WO2018117885A1 - Pla - based active and degradable biocomposites for food packaging - Google Patents

Pla - based active and degradable biocomposites for food packaging Download PDF

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Publication number
WO2018117885A1
WO2018117885A1 PCT/RO2016/000028 RO2016000028W WO2018117885A1 WO 2018117885 A1 WO2018117885 A1 WO 2018117885A1 RO 2016000028 W RO2016000028 W RO 2016000028W WO 2018117885 A1 WO2018117885 A1 WO 2018117885A1
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WIPO (PCT)
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pla
biocomposites
exemple
chitosan
antimicrobial
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PCT/RO2016/000028
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French (fr)
Inventor
Maria RĂPĂ
Cornelia Vasile
Elena Grosu
Ancuta Roxana Trifoi
Raluca Nicoleta Darie-Niţă
Elena Butnaru
Raluca Petronela Dumitriu
Madlatuå SIVERTSVIK Morten
Jan Thomas ROSNES
Amalia-Carmen Miteluţ
Elisabeta Elena POPA
Bogdanel Sivestru MUNTEANU
Laurenţiu Moldovan
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S.C. Institutul De Cercetari Produse Auxiliare Organice S.A.
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Publication of WO2018117885A1 publication Critical patent/WO2018117885A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/20—Compounding polymers with additives, e.g. colouring
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
    • C08G63/06—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from hydroxycarboxylic acids
    • C08G63/08—Lactones or lactides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/20—Compounding polymers with additives, e.g. colouring
    • C08J3/22—Compounding polymers with additives, e.g. colouring using masterbatch techniques
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
    • C08L67/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • C08J2367/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones

Definitions

  • Antimicrobial activity of these agents is attributed to some classes of compounds which constitue volatile fraction, such as hydrocarbons terpenes, oxygenated terpene, aldehydes, ketones and esters, carnosic acid, carnosol, rosmarinic acid, or others, like eugenol, carvacrol, thymol (containing oregano).
  • Antimicrobial agents can be added either directly into a bag placed within the package, or through incorporation into the composition of the product packing material or by the coating technique of the packaging surface, or by using antimicrobials polymers which exhibit film-forming properties [3, 4].
  • the active substance incorporated into the package by any technique, in contact with food, either solid or liquid, it releases slowly and inhibits the microbiological or oxidative degradation phenomena, responsible for canned and packaged food inacceptability.
  • PLA Polylactic acid
  • PLA is commercialized by companies like Cargill and Dow Chemicals. Its good transparency, high modulus and rigidity at room temperature recommend him as food packaging material with short-use [6].
  • PLA offer barrier properties comparable to those provided by PET.
  • PLA is potentially degradable in the soil, compost or in the human body by hydrolysis. In the degradative process, after 40-60 days at 50-60 °C, PLA is hydrolyzed into small molecules (oligomers, dimers, monomers). These compounds are then degraded in C0 2 and H 2 0 by microorganisms from the compost or soil.
  • the lactic acid as a product of degradation of PLA is known as a normal component of metabolism in the human body which is converted into carbon dioxide and water in acetic acid cycle [9, 10].
  • packaging materials based PLA are considered as safe materials both in terms of food and for environmental protection [11].
  • PLA due to low water vapor and oxygen permeability, low mechanical and thermal properties, fragility and heat deflection temperature and the high cost, PLA exhibit limitations for use in the food packaging.
  • plasticizers In order to eliminate PLA's deficiencies, is recommended improving the properties of PLA by modifying it with plasticizers, blending with other polymers, such as poly (butylene adipate-co- terephthalate) PBAT [12, 13], poly (hydroxybutyrate) [14, 15], etc., the copolymerization and incorporation of the fillers [16].
  • plasticizers which have been extensively studied for plasticizing PLA it include: poly (ethylene glycol) (PEG), citrate esters, glycerol triacetate, monoesters of glucose, fatty acid esters, lactide and oligomers of lactide, etc. [17-19].
  • plasticizers for modifying the properties of biopolymers is limited by the technical and legislative requirements (Directive 2002-72-EC) to achieve food packaging.
  • Using of plasticizers leads to a significant improvement in elongation, to the detriment of tensile strength, in addition occuring the possibility of their migration during time from the PLA matrix.
  • Chitosan is widely used for obtaining of antimicrobial film for edible coating to reduce water vapor and oxygen transmission, to diminish the rate of breathing and increase the shelf life of the fruit [20].
  • PET polyethylene terephthalate
  • chitosan as a potential packaging active material for protecting the meat against Salmonella enter ica, Campylobacter spp., Escherichia coli, Listeria monocytogenes and Candida albicans [21] or low density polyethylene (LDPE) [22] to increase shelf life of poultry meat.
  • Antimicrobial nature of chitosan is mainly due of its amino groups positively charged that interact with negatively charged microbial cell membranes [23].
  • thermoformed plastics polyethylene terephthalate or polyethylene or polystyrene impact-resistant and two layers of metallic vapor of tin or aluminum vapor deposited on the each layer of thermoformed thermoplastic material and a recessed cavity which is in contact with the food surface.
  • an antimicrobial composition for food packaging consists of: salicylaldehyde; ii) carvacrol, thymol, or a mixture thereof; and in some embodiment iii) other components and excipients without any antimicrobial activity intended for active coating of food packaging.
  • thermoplastic polymers LDPE, PLA and PCL
  • a method for obtaining an antimicrobial packaging in the form of film based on thermoplastic polymers comprising the step of mixing a thermoplastic polymer which has a melting point less than or equal to 160 ° C at a temperature less than or equal to 160 0 C, and an antimicrobial substance type: lysozyme, thymol or extract of lemon subjected to the mixture obtained by the compression at the same temperature as indicated above.
  • the technical problem solved by the invention consists in the obtaining of polylactic acid - based active biocomposites, chitosan modified with rosehip oil and / or nanoclay, bioplasticizers and additives with antimicrobial and antioxidant action by mixing in the melt on similar equipments to those used to process conventional polymers, which have the following characteristics:
  • bioactive antibacterial component itself a bioactive antibacterial component was modified by encapsulating within the composition of two bioactive components, namely: rosehip oil derived from cold pressing of the seeds and nanoclay type C30B, all components acting synergistically to create a bioactive food packaging; - by adjusting the plasticizer content from the recipe it can get either flexible or rigid food packaging;
  • Polymeric composition based on polylactic acid and modified chitosan for obtaining of bioactive polymeric composites eliminates the disadvantages of known products, in that they are constituted of a mixture composed of: PLA Ingeo type 2003D from 76 to 79.2%, LAPOL 108 as masterbatch form from 7.64 to 19.6%, PEG BioULTRA 4000 from 5.79 to 11.88%, chitosan with average molecular weight modified with rosehip oil cold pressed and / or nanoclay 0-3%, vitamin E 1%, BYP P-4101 0.5-3% and HPS 0-2% additives, the percentages being expressed in weight percent.
  • the process for preparing active biocomposites consists in the fact that the processing of the polymer blend is based on bringing the raw materials in the molten state in a Brabender Plastograph, provided with a mixing chamber of 50 cm 3 , at a temperature of 170 ⁇ 5 ° C, mixing time 6 min., and a speed of the screws of 60 rotations per minute.
  • PLA is very hygroscopic and will retain moisture from the air, leading to degradation of macromolecular chains, reducing product viscosity and resistance. Therefore, prior to use, polylactic acid (PLA) and the plasticizer LAPOL 108 as masterbatch are dried in an oven with air circulation at a temperature of 50 °C for 24 hours (moisture content ⁇ 200 ppm).
  • encapsulated chitosan with rosehip and/or clay is dried in an oven with air circulation at 40 °C for 4 h.
  • the mixture melted and homogenized is hot-pressed on a laboratory press under the following conditions: preheat - for 5 minutes, the temperature of 175 °C, pressing - for 10 minutes, the temperature of 175 °C and the pressure of 147 barr and cooling - for 20 minutes in order to obtain thin homogeneous films with dimensions 200x200x0.1 mm and homogeneous plates with dimensions of 150x150x1 mm. It was taken specimens from these films and plates for testing the physical and mechanical properties, thermal and antimicrobial activity.
  • the invention as described above, present the advantage that is obtained biocomposites based on polylactic acid, modified chitosan, additives and bioactive agents which shows processability improved and physical-mechanical, barrier and antimicrobial activity appropriate to use of packaging for food.
  • Lapol®108 is a bioplasticizer patented (US 7,842,761 B2), obtained from renewable resources, used for improving polymers processing by standard procedures, such as: injection molding, extrusion and thermoforming. It provides hardness and flexibility of polymer recipe without diminishing the modulus of elasticity, while reduces the glass transition temperature. It is compatible and miscible with PLA and other polymers (without necessity of other compatible or additives).
  • Vitamin E ⁇ a-Tocopherol
  • bioactive agent Sigma-Aldrich presents the density of 0.95 g / cm 3 (20 °C) and the chemical structure shown in Figure 4.
  • BYK-P 4101 is a copolymer which contains acid groups which ensures adsorption of the silica dioxide powder (BYK-Chemie GmbH); It shows the bulk density 530 kg/m 3 , is an additive for processing that interact strongly at the matrix interface, with the role of improving the conditions for processing and maintaining or even improving the physical and mechanical properties such as tensile strength, modulus of elasticity being approved for applications that involve contact with food.
  • 39.2 g PLA is melt mix with 9.8 g Lapol 108 plasticizer on a Brabender Plastograph, equipped with a mixing cuve of 50 cm 3 at a temperature of 170 ⁇ 5 0 C, at 60 rpm for 2 minutes. Then, 0.52 ml vitamin E and 0.5 g chitosan modified with rosehip oil cold pressed were added to the molten mixture. Melt mixing is continued up to 6 minutes.
  • Example no. 2 and 3 0.5 g BYK-P4101 and 1.5 g BYK-P4101 additives respectively are added to the composition of Example no. 1, so that the mass ratio between the PLA and the Lapol 108 plasticizer is 80:20.
  • composition based on PLA, plasticizer, chitosan modified and BYK-P4104 additive, in weight percent is shown in Table 1.
  • the homogeneous plates with dimensions (150x150x1) mm and homogeneous and thin films with dimensions (200x200x0.1) mm were prepared by compression-molding using a hydraulic press in the following conditions: preheating - 5 min at a temperature of 175 °C, press - 10 min., at a temperature of 175 °C and a pressure of 147 barr and cooling - 20 min. Specimens were prepared from these plates and films for testing of tensile, and thermal (differential scanning calorimetry (DSC)) properties, water vapor transmission rate, antimicrobial and antioxidant activity.
  • DSC thermal scanning calorimetry
  • the addition of the BYP-P4101 additive to the PLA plasticized formulations containing modified chitosan has the effect of increasing the antimicrobial activity (log reduction of 4.42 to 4.71 against E. coli) - Table 5 - Example no. 2 and Example no. 3, the reduction of tensile strength PLA of biocomposites -14% in the case of the incorporation of 1% BYK and ⁇ 48% in the case of the incorporation of 3% BYK respectively, compared to neat PLA (Table 8) - Example 2 and Example 3, and also, to improve the water vapor transmission rate (13.76 g/m 2 / 24 h in the case of biocomposite containing 3% BYK) - Table 9 - Example 3.
  • the glass transition temperature (T g ), the melting temperature (T m ) and the degree of crystallinity of the PLA (X c ) decrease with the addition of the BYK additive - Table 10 - Example no. 2 and Example no. 3.
  • Biocomposite containing the BYK-P 4101 additive at 1% concentration has a higher antioxidant activity (percent inhibition of 29,9%) compared to the other samples - Table 7 - Example no. 2.
  • PLA 39.2 g PLA is melt mix with 6.86 g Lapoll08 plasticizer on a Brabefider Plastograph, equipped with a mixing cuve of 50 cm 3 at a temperature of 170 ⁇ 5 0 C, at 60 rpm for 2 minutes. Then, 2.94 g PEG BioUltra 4000, 0.52 ml vitamin E and 0.5 g chitosan modified with rosehip oil cold pressed were added to the molten mixture. Melt mixing is continued up to 6 minutes.
  • Example no. 5 0.25 g BYK-P4101 and 0.5 g HPS additives respectively are added to the composition of Example no. 4, so that the mass ratio between the PLA and plasticizers is 80:20 and those between LAPOL 108 and PEG BioULTRA 4000 is 70:30.
  • composition based on PLA, plasticizers, chitosan modified with rosehip oil cold pressed and B YK-P4104 and HPS additives, in weight percent, is shown in Table 2.
  • Example no. 5 and Example no. 4 record a log reduction of 1.5 - 1.8 against E. coli and of 2.2 - 3 against S. aureus - Table 5 and Table 6.
  • the sample containing modified chitosan with rosehip oil cold pressed shows a tensile strength greater (29 MPa)- Exemple no. 4, while the sample containing HPS and BYK additives shows a decrease in tensile strength (17 MPa) and a higher antioxidant activity (23,53%) - Exemple no. 5.
  • Example no. 4 and Example no. 5 For those two samples (Example no. 4 and Example no.
  • 39.2 g PLA is melt mix with 5.88 g Lapol 108 plasticizer on a Brabender Plastograph, equipped with a mixing cuve of 50 cm 3 at a temperature of 170 ⁇ 5 0 C, at 60 rpm for 2 minutes. Then, 3.92 g PEG BioUltra 4000, 0.52 ml vitamin E and 0.5 g chitosan modified with rosehip oil cold pressed were added to the molten mixture. Melt mixing is continued up to 6 minutes.
  • chitosan is modified with rosehip oil and purified sodium montmorillonite (C30B) in following quantities: 0.5 g, 1 g and 1.5 g respectively, so that the mass ratio between the PLA and plasticizers is 80:20 and those between LAPOL 108 and PEG BioULTRA 4000 is 60:40.
  • C30B purified sodium montmorillonite
  • composition based on PLA, plasticizers, chitosan modified with rosehip oil cold pressed and sodium montmorillonite, in weight percent, is shown in Table 3.
  • Example no. 11 for which the tensile strength is 28 MPa, the tensile strength decreases with incorporation of 1% chitosan modified with rosehip oil cold pressed and sodium montmorillonite respectively - Exemples no. 7 and 8 (21-23 MPa), but with increasing of the antimicrobial agent content modified with sodium montmorillonite - Examples no.
  • 39.2 g PLA is melt mix with 3.92 g Lapol 108 plasticizer on a Brabender Plastograph, equipped with a mixing cuve of 50 cm at a temperature of 170 ⁇ 5 ° C, at 60 rpm for 2 minutes. Then, 5.88 g PEG BioUltra 4000, 0.52 ml vitamin E and 0.5 g chitosan modified with rosehip oil cold pressed were added to the molten mixture. Melt mixing is continued up to 6 minutes.
  • chitosan is modified with rosehip oil and purified sodium montmorillonite (C30B) in following quantities: 0.5 g and 1 g respectively and added to the composition from Exemple 12, so that the mass ratio between the PLA and plasticizers is 80:20 and those between LAPOL 108 and PEG BioULTRA 4000 is 40:60.
  • C30B purified sodium montmorillonite
  • Exemple no. 17 is considered as reference for Exemples no. 12-16.
  • composition based on PLA, plasticizers, chitosan modified with rosehip oil cold pressed and sodium montmorillonite, in weight percent, is shown in Table 4.
  • the tensile strength decreased with ⁇ 50% for all samples and the elongation at break is in the range of 5-12% (Table 8) - Examples no. 12-16, and the water vapor transmission rate does not differ significantly.
  • the antimicrobial activity is in the range of 1.3 - 3.5 log reduction against E. coli and 2.2-3.1 against S. aureus respectively (Table 5 and Table 6) - Examples 12-16.
  • the glass transition temperature increases than reference with adding of modified chitosan, which has an effect to increase the degree of crystallinity of PLA (Table 10) - Examples 12-16.
  • Antimicrobial activity was performed in accordance with the ISO 22196:2007. The method involve placing a droplet of a suspension of either Escherichia coli ATCC 8739 or Staphylococcus aureus ATCC 6538 directly onto the material surface (50 x 50 mm) being tested. Each test specimen; treated and untreated was prepared in a separate sterile Petri dish with the test surface uppermost and 0.4 ml of the test inoculum with concentration between 2.5 xlO 5 cells/ml and lOxlO 5 cells/ml was pipetted onto the test surface.
  • test inoculum was covered with a piece of neutral film (without anti-bacterial properties, 40 x 40 mm) and gently pressed down on the film so that the test inoculum spreads to the edges.
  • SCDLP serum casein digest broth with lecithin and polyoxyethylene sorbitan monooleate
  • R is the antibacterial activity
  • Uo is the average of the common logarithm of the number of viable bacteria, in cells/cm 2 , recovered from the untreated test specimens immediately after inoculation;
  • U t is the average of the common logarithm of the number of viable bacteria, in cells/cm 2 , recovered from the untreated test specimens after 24 h;
  • a t is the average of the common logarithm of the number of viable bacteria, in cells/cm 2 , recovered from the treated test specimens after 24 h.
  • the tensile properties were determined according to EN ISO 527-2:201 1 using an Instron 3345 tester (USA) on specimens with thickness of 1 mm and length of 40 mm. Test machine operated at a crosshead speed of 10 mm/min. At least five specimens were tested for each composition and the average value is reported in Table 8. The influence of plasticizer content on the tensile properties of PLA- based active biocompositions and modified chitosan with respect to plasticized PLA is shown in Figures 5-7. Water vapor transmission rate.
  • WVTR Water vapor transmission rate
  • DSC Differential scanning calorimetry
  • Table 7 shows that the antioxidant activity decreases with increasing of ratio between plasticizers and the biocomposites containing the plasticizers ratio of 40:60 and modified chitosan have a higher antioxidant activity (Example no. 13, Example no. 15 and Example no. 16).
  • the elongation at break can has different values, depending on the intended use of the food packaging ( Figure 6).
  • Figure 6 the mass ratio between PEG and Lapol 108
  • it can pick up the sample containing 40:60 weight ratio between Lapol 108 and PEG without the need to add modified chitosan (Example no. 17, elongation at break of 239 %).
  • This sample shows antimicrobial activity due to the vitamin E content from composition.
  • Table 9 shows that with increasing of bioplasticizer content from PLA biocomposites, the water vapor permeability increased, from 15.94 g/m /24 h for the neat PLA to 21.97 g/m 2 /24 h in the case of ratio between plasticizers of 70/30, to 28.09 g/m 2 /24 h when the ratio between plasticizers is 60/40 and to 37.45 g/m 2 /24 h respectively if the plasticizers ratio is 40/60 (Example no. 6, Example no. 11, Example no. 17).
  • Plasticizer content influence on the tensile strength at break of the PLA-based active biocomposites and modified chitosan.
  • the caption indicates the ratio between Lapol 108/PEG BioULTRA 4000 plasticizers

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Abstract

The invention relates to compositions for obtaining of active biocomposites for food use applications, and to a process for obtaining them. The process for obtaining them according to the invention comprises in the melt mixing a blend consisting of a polylactic acid type 2003D polymeric matrix, modified chitosan with average molecular weight and additives having antimicrobial / antioxidant activity, at a temperature of 170°C, mixing time 6 min and a speed of 60 rotations per minute.

Description

PLA - BASED ACTIVE AND DEGRADABLE BIOCOMPOSITES FOR FOOD
PACKAGING
REFERENCES
[I] Lopez O.V., Castillo L.A., Garcia M.A., Villar M.A., Barbosa S.E., Food packaging bags based on thermoplastic corn starch reinforced with talc nanoparticles, Food Hydrocolloids 2015;43:18-24.
[2] Lucera A., Costa C, Conte A. and Del Nobile M.A. Food applications of natural antimicrobial compounds, Front. Microbio. 2012;3:287.
[3] Appendini P., Hotchkiss J. H. Review of antimicrobial food packaging. Inno.Food Sci. Emerg. Technol. 2002;3 : 1 13-126.
[4] Hanusova K., Dobias J., Klaudisova K. Effect of packaging films releasing antimicrobial agents on stability of food products. Czech J. Food Sci. 2009;27:347-349.
[5] Petersen, K., Nielsen, P. and Olsen, M. Physical and mechanical properties of biobased materials-starch, polylactate and polyhydroxybutyrate. Starch, 2001 ;53:356-361.
[6] Ansari S., Fatma T., Polyhydroxybutyrate - A Biodegradable Plastic and its Various Formulations, International Journal of Innovative Research in Science, Engineering and Technology, 2014;Vol. 3, Issue 2, 9494- 9499, ISSN: 2319-8753.
[7] Pranamuda H., Tokiwa Y., Tanaka H., Polylactide Degradation by an Amycolatopsis sp., Applied and Environmental Microbiology, 1997;vol 63, no.4, 1637-1640.
[8] Tokiwa Y., Calabia B. P., Biodegradability and biodegradation of poly(lactide), Appl Microbiol Biotechnol, 2006;72:244-251, DOI 10.1007/s00253-006-0488-l.
[9] Maurus, P. B, & Kaeding, C. C. Bioabsorbable implant material review. Operation Techniques and Sport Medicine, 2004;12, 158-60.
[10] Vert M. After soft tissues, bone, drug delivery and packaging, PLA aims at blood. Eur Polym J, 2015. http://dx.doi.org/l 0.1016/i .eurpolvmi .2015.03.051.
[I I] Ahmed J. and Varshney S.K. (2011). Polylactides - chemistry, properties and green packaging technology: a review. International Journal of Food Properties, 14: 37-58.
[12] Al-Itry R., Lamnawar K., Maazouz A. Reactive extrusion of PLA, PBAT with a multifunctional epoxide: physico-chemical and rheological properties Eur Polym J 2014;58:90-102.
[13] Gu S.Y., Zhang K., Ren J., Zhan H. Melt rheology of polylactide/poly)butylene adipate-co- terephthalate blends. Carbohyd Polym 2008;74:79-85.
[14] Reddy M.M., Vivekanandhan S., Misra M., Bhatia S.K., Mohanty A.K. Biobased plastics and bionanocomposites: Current status and future opportunities. Prog Polym Sci 20l3;38(10-l l): 165;3i- 1689. [15] Arrieta M.P., Lopez J., Lopez D., Kenny J.M., Peponi L., Effect of chitosan and catechin addition on the structural, thermal, mechanical and disintegration properties of plasticized electrospun PLA-PHB biocomposites. Polymer Degradation and Stability 132 (2016) 145-156.
[16] Mekonnen T., Mussone P., Khalil H., Bressler D. Progress in bio-based plastics and plasticizing modifications. J Mater Chem Al, 2013;13379-13398.
[17] Hassouna F., Raquez J.M., Addiego F., Toniazzo V., Dubois P., Ruch D. New development on plasticized poly (lactide): chemical grafting of citrate on PLA by reactive extrusion. Eur. Polym. J. 2012;48(2):404-415.
[18] Herrera N., Mathew A.P., Oksman K. Plasticized polylactic acid/cellulose nanocomposites prepared using melt-extrusion and liquid feeding: Mechanical, thermal and optical properties. Compos. Sci. Technol. 2015;106:149-155.
[19] Tee Y.B., Talib R.A., Abdan K., Chin N.L., Basha R.K., Md Yunos K.F. Toughening poly(lactic acid) and aiding the melt-compounding with bio-sourced plasticizers. Agric Agric Sci Procedia 2014;2:289-295. DOI: 10.1016/j.aaspro.2014.11.041.
[20] Dutta P.K., Tripathi S., Mehrotra G.K., Dutta J., Perspectives for chitosan based antimicrobial films in food applications, Food Chemistry, 2009, Volume 114, Issue 4, 1173-1182.
[21] Fras Zemljic L., Tkavc T., Vesel A., Sauperl O. Chitosan coatings onto polyethylene terephthalate for the development of potential active packaging material, Appl Surf Sci
2013;265:697-703.
[22] Quiroz-Castillo J.M., Rodriguez-Felix D.E., Grijalva-Monteverde H., del Castillo-Castro T., Plascencia-Jatomea M., Rodriguez-Felix F., Herrera-Franco P.J. Preparation of extruded polyethylene/chitosan blends compatibilized with polyethylene-graft-maleic anhydride. Carbohyd Polym 2014;101:1094-1100.
[23] Sanches-Silva A., Costa H.S., Losada P.P., Sendon R., Sanchez-Machado D.I., Valdez H.S.,
Varona I.A., Lopez-Cervantes J. Preparation of active packaging with antioxidant and antimicrobial activity based on astaxanthin and chitosan. Nutr Bull 2010;35:268-271.
[24] WO 2015026313 Al.
[25] WO 2004056214 A2.
[26] US2016325911 Al.
[27] EP 1657181 Bl.
[28] WO 2010057658 A9.
[29] US 8828516 B2.
[30] OSIM File no. A/00576/11.08.2016.
[31] Bonilla J., Fortunati E., Vargas M., Chiralt A., Kenny J.M. Effects of chitosan on the' physicochemical and antimicrobial properties of PLA films. J Food Eng 2013;119:236-243. DESCRIPTION OF THE INVENTION
PLA - BASED ACTIVE AND DEGRADABLE BIOCOMPOSITES FOR FOOD
PACKAGING
Currently, food packaging market is in a continuous growth in order to meet the demands of the global population. Numerous efforts are made to develop specific packages to present simultaneously mechanical, thermal, optical and barrier adequate properties in order to ensure full quality of food [1]. At the same time, the materials used for packaging of food must have antibacterial properties.
In recent years it have been developed "active" systems for packaging of fresh food (such as meat, fish, cheese, fruit or vegetables), based on the polymer materials in which it were incorporated additives with antimicrobial and / or antioxidant properties. These materials are used in order to obtain rigid or flexible packages, which provide the extension of the preservation of foodstuffs stored at ambient or refrigerator temperature. Antimicrobial agents added to packaging materials, are for example: nisin, chitosan, herbal essential oils (rosemary (Rosmarinus officinalis), oregano (Origanum vulgare), sage (Salvia officinalis), etc.) [2]. Antimicrobial activity of these agents is attributed to some classes of compounds which constitue volatile fraction, such as hydrocarbons terpenes, oxygenated terpene, aldehydes, ketones and esters, carnosic acid, carnosol, rosmarinic acid, or others, like eugenol, carvacrol, thymol (containing oregano).
Antimicrobial agents can be added either directly into a bag placed within the package, or through incorporation into the composition of the product packing material or by the coating technique of the packaging surface, or by using antimicrobials polymers which exhibit film-forming properties [3, 4]. The active substance incorporated into the package by any technique, in contact with food, either solid or liquid, it releases slowly and inhibits the microbiological or oxidative degradation phenomena, responsible for canned and packaged food inacceptability.
Also, consumer awareness on environmental protection has increased and the demand for food packaging achieved with recycled materials and eventually biodegradable. In the case of additives with antimicrobial and / or antioxidant activity there is a growing demand that they be as "natural" as possible, to avoid the risk of poisoning or allergic reactions.
Most food packaging materials are obtained from conventional polymers, such as polyethylene, polyethylene terephthalate, polypropylene, polystyrene. These polymers are ideal candidates for food packaging in safe conditions and comply with national and international regulations. Despite these advantages, conventional packaging materials are a huge problem because of long persistenc in the environment and lack of biodegradability. In addition, it is known that petrochemical resources are limites. In this context, the research on the environment-friendly materials has escalated lately.
Polylactic acid (PLA) has received special attention in recent decades as one of the most attractive packing materials due to its biodegradability, and lack of ecotoxicity and biocompatibility [5]. PLA is a biopolymer whose structure is presented in Figure 1, is produced chemically from renewable resources, especially from sugar and starch or cellulose, requires small amount of energy for its production compared to oil resources. During PLA's degradation there is forming a small amount of C02, its use leading to reduce the greenhouse effect from atmosphere.
Figure imgf000005_0001
Figure 1. The chemical structure of the polylactic acid
Currently, PLA is commercialized by companies like Cargill and Dow Chemicals. Its good transparency, high modulus and rigidity at room temperature recommend him as food packaging material with short-use [6]. PLA offer barrier properties comparable to those provided by PET. PLA is potentially degradable in the soil, compost or in the human body by hydrolysis. In the degradative process, after 40-60 days at 50-60 °C, PLA is hydrolyzed into small molecules (oligomers, dimers, monomers). These compounds are then degraded in C02 and H20 by microorganisms from the compost or soil. The lactic acid as a product of degradation of PLA is known as a normal component of metabolism in the human body which is converted into carbon dioxide and water in acetic acid cycle [9, 10].
Therefore, the packaging materials based PLA are considered as safe materials both in terms of food and for environmental protection [11].
However, due to low water vapor and oxygen permeability, low mechanical and thermal properties, fragility and heat deflection temperature and the high cost, PLA exhibit limitations for use in the food packaging.
In order to eliminate PLA's deficiencies, is recommended improving the properties of PLA by modifying it with plasticizers, blending with other polymers, such as poly (butylene adipate-co- terephthalate) PBAT [12, 13], poly (hydroxybutyrate) [14, 15], etc., the copolymerization and incorporation of the fillers [16]. Among the plasticizers which have been extensively studied for plasticizing PLA it include: poly (ethylene glycol) (PEG), citrate esters, glycerol triacetate, monoesters of glucose, fatty acid esters, lactide and oligomers of lactide, etc. [17-19]. Selecting of plasticizers for modifying the properties of biopolymers is limited by the technical and legislative requirements (Directive 2002-72-EC) to achieve food packaging. Using of plasticizers leads to a significant improvement in elongation, to the detriment of tensile strength, in addition occuring the possibility of their migration during time from the PLA matrix.
Chitosan is the second most widespread polysaccharide in nature after cellulose, obtained by alkaline deacetylation of chitin. Due to its antimicrobial activity, non-toxicity and biodegradability, it exhibits a great potential for using as packaging material. Chitosan is marketed in sorts with different average molecular weights and degrees of deacetylation. Structure of chitosan and chitin are presented in Figure 2, where p and q are fractions of glucosamine and N-acetyl glucosamine monomers, and they are comprises between 0 and 1. The sum p + q = 1. For chitin, q→ 1 and the molecule is almost com let acetylated. In the case of chitosan, q < 0,5.
Figure imgf000006_0001
Figure 2. Chemical structure of chitosan and chitine
Chitosan is widely used for obtaining of antimicrobial film for edible coating to reduce water vapor and oxygen transmission, to diminish the rate of breathing and increase the shelf life of the fruit [20]. In several studies have reported coatings of polyethylene terephthalate (PET) with chitosan as a potential packaging active material for protecting the meat against Salmonella enter ica, Campylobacter spp., Escherichia coli, Listeria monocytogenes and Candida albicans [21] or low density polyethylene ( LDPE) [22] to increase shelf life of poultry meat. Antimicrobial nature of chitosan is mainly due of its amino groups positively charged that interact with negatively charged microbial cell membranes [23].
It is known from the WO 2,015,026,313 Al patent [24] a laminated metalized structure in order to achieve rigid food packaging, formed of two layers of thermoformed plastics - polyethylene terephthalate or polyethylene or polystyrene impact-resistant and two layers of metallic vapor of tin or aluminum vapor deposited on the each layer of thermoformed thermoplastic material and a recessed cavity which is in contact with the food surface.
Such packaging does not solve the problem of nonbiodegradable plastics.
It is known from the WO 2,004,056,214 A2 patent [25] a method for preparation of bioactive packaging materials composed of synthetic polymers and the natural resources that are coated with a polymer layer containing the preservatives in the form of solutions or dispersions in water or organic solvents and mixtures thereof or in the form of laquers. It is known from the US 2,016,325,911 Al patent [26] an antimicrobial composition for food packaging consists of: salicylaldehyde; ii) carvacrol, thymol, or a mixture thereof; and in some embodiment iii) other components and excipients without any antimicrobial activity intended for active coating of food packaging.
It is known from the EP 1,657,181 Bl patent [27] getting an antimicrobial packaging by coating a nitrocellulose substrate, acrylics, and vinyl compounds with essential oils from plants that contain antibacterial agents, antifungal agents and antioxidants dissolved or dispersed in the range 0.1% to 10% by weight of the final active liquid.
It is known also from the WO 2,010,057,658 A9 patent [28] a method for obtaining an antimicrobial packaging in the form of film based on thermoplastic polymers (LDPE, PLA and PCL) incorporating the substances with antimicrobial activity comprising the step of mixing a thermoplastic polymer which has a melting point less than or equal to 160 ° C at a temperature less than or equal to 160 0 C, and an antimicrobial substance type: lysozyme, thymol or extract of lemon subjected to the mixture obtained by the compression at the same temperature as indicated above.
These polymeric mixtures for antimicrobial packaging present the disadvantage that they are obtained in the laboratory using organic solvents and natural extracts are volatile.
It is known from the US 8,828,516 B2 patent [29] a method for obtaining an active food package in the form of an absorbent non-woven fabric integrated into a biodegradable polymer (preferably fibers from polylactic acid) from which silver ions are released.
The disadvantage of using this type of package is the existence of the health risks associated with the use of silver nanoparticles, the color, taste or smell of the food to be affected by ions of silver, and also the availability of large quantities of metal required to obtain an antibacterial effect (1-5% by weight).
The technical problem solved by the invention consists in the obtaining of polylactic acid - based active biocomposites, chitosan modified with rosehip oil and / or nanoclay, bioplasticizers and additives with antimicrobial and antioxidant action by mixing in the melt on similar equipments to those used to process conventional polymers, which have the following characteristics:
- raw materials (poliactic acid, chitosan, rosehip oil cold pressed, plasticizers) used are obtained from renewable resources, non-threatening environment protection and consumer safety;
- method of obtaining the polymer blends in the melt is relatively simple, without solvent consumption;
- chitosan itself a bioactive antibacterial component was modified by encapsulating within the composition of two bioactive components, namely: rosehip oil derived from cold pressing of the seeds and nanoclay type C30B, all components acting synergistically to create a bioactive food packaging; - by adjusting the plasticizer content from the recipe it can get either flexible or rigid food packaging;
- active components do not migrate from the packaging recipe to the packaged food product;
- they are used small amounts of antimicrobial / antioxidants agents to reduce the number of microorganisms on the surface of food packaging and implicitly on packaged food product with consequences on increasing the shelf life of the packaged product and on the health and safety of consumers.
Polymeric composition based on polylactic acid and modified chitosan for obtaining of bioactive polymeric composites, according to the present invention, eliminates the disadvantages of known products, in that they are constituted of a mixture composed of: PLA Ingeo type 2003D from 76 to 79.2%, LAPOL 108 as masterbatch form from 7.64 to 19.6%, PEG BioULTRA 4000 from 5.79 to 11.88%, chitosan with average molecular weight modified with rosehip oil cold pressed and / or nanoclay 0-3%, vitamin E 1%, BYP P-4101 0.5-3% and HPS 0-2% additives, the percentages being expressed in weight percent.
The process for preparing active biocomposites, according to the invention, consists in the fact that the processing of the polymer blend is based on bringing the raw materials in the molten state in a Brabender Plastograph, provided with a mixing chamber of 50 cm3, at a temperature of 170 ± 5 ° C, mixing time 6 min., and a speed of the screws of 60 rotations per minute. PLA is very hygroscopic and will retain moisture from the air, leading to degradation of macromolecular chains, reducing product viscosity and resistance. Therefore, prior to use, polylactic acid (PLA) and the plasticizer LAPOL 108 as masterbatch are dried in an oven with air circulation at a temperature of 50 °C for 24 hours (moisture content <200 ppm).
Also, encapsulated chitosan with rosehip and/or clay is dried in an oven with air circulation at 40 °C for 4 h. The mixture melted and homogenized is hot-pressed on a laboratory press under the following conditions: preheat - for 5 minutes, the temperature of 175 °C, pressing - for 10 minutes, the temperature of 175 °C and the pressure of 147 barr and cooling - for 20 minutes in order to obtain thin homogeneous films with dimensions 200x200x0.1 mm and homogeneous plates with dimensions of 150x150x1 mm. It was taken specimens from these films and plates for testing the physical and mechanical properties, thermal and antimicrobial activity.
The invention, as described above, present the advantage that is obtained biocomposites based on polylactic acid, modified chitosan, additives and bioactive agents which shows processability improved and physical-mechanical, barrier and antimicrobial activity appropriate to use of packaging for food.
In order to obtain biocomposites which make the subject of the present invention the following materials were used: - Polylactic acid (PLA) Ingeo®Biopolimer 2003 D (NatureWorks LLC), granules, that exhibit: residual monomer content of 0.22%, isomer type D 4.4%, specific weight 1.24 g/cm3, MFR, (210 °C, 2.16 kg) 6 g/10 min, tensile strength 53 MPa, modulus of elasticity 3.5 GPa, elongation at break 6.0%;
Chitosan with average molecular weight modified by encapsulating of rosehip oil and respectively purified sodium montmorillonite (Cloisite C30B) by emulsion-solvent evaporation technique, according to proposed patent deposed with OSIM File No. A / 00 576 / 08.11.2016 [30]
- LAPOL 108 in the form of masterbatch with 70% PLA - granules (LAPOL, LLC, USA). Lapol®108 is a bioplasticizer patented (US 7,842,761 B2), obtained from renewable resources, used for improving polymers processing by standard procedures, such as: injection molding, extrusion and thermoforming. It provides hardness and flexibility of polymer recipe without diminishing the modulus of elasticity, while reduces the glass transition temperature. It is compatible and miscible with PLA and other polymers (without necessity of other compatible or additives).
- Polyethylene glycol BioULTRA 4,000 (Sigma-Aldrich), in the form of pellets, shows: molecular weight (calculated from the OH index) 4,016 g/mol, melting point of 61 °C and the chemical structure resented in Figure 3.
Figure imgf000009_0001
Figure 3. The chemical structure of polyethylene glycol
- Vitamin E (± a-Tocopherol) - bioactive agent (Sigma-Aldrich) presents the density of 0.95 g / cm3 (20 °C) and the chemical structure shown in Figure 4.
Figure imgf000009_0002
Figure 4. The chemical structure of vitamin E
- montmorilonite unmodified (Dellite HPS) (Laviosa, Chimica Mineraria S.P.A. Italia);
- BYK-P 4101 is a copolymer which contains acid groups which ensures adsorption of the silica dioxide powder (BYK-Chemie GmbH); It shows the bulk density 530 kg/m3, is an additive for processing that interact strongly at the matrix interface, with the role of improving the conditions for processing and maintaining or even improving the physical and mechanical properties such as tensile strength, modulus of elasticity being approved for applications that involve contact with food.
In the followings, it is presented 17 examples of active polymeric biocomposites and the method of manufacturing thereof according to the invention. Their compositions are summarized in Tables 1-4 and the mechanical, thermal, water vapor permeability, antimicrobial and antioxidant activity are presented in Tables 5-10 and Figures 5-11.
Exemples no. 1-3:
39.2 g PLA is melt mix with 9.8 g Lapol 108 plasticizer on a Brabender Plastograph, equipped with a mixing cuve of 50 cm3 at a temperature of 170 ± 5 0 C, at 60 rpm for 2 minutes. Then, 0.52 ml vitamin E and 0.5 g chitosan modified with rosehip oil cold pressed were added to the molten mixture. Melt mixing is continued up to 6 minutes.
In the Examples no. 2 and 3, 0.5 g BYK-P4101 and 1.5 g BYK-P4101 additives respectively are added to the composition of Example no. 1, so that the mass ratio between the PLA and the Lapol 108 plasticizer is 80:20.
The composition based on PLA, plasticizer, chitosan modified and BYK-P4104 additive, in weight percent is shown in Table 1.
Table 1 - Composition of obtained biocomposites according to Exemples no. 1-3
Figure imgf000010_0001
Once the melted products were obtained, the homogeneous plates with dimensions (150x150x1) mm and homogeneous and thin films with dimensions (200x200x0.1) mm were prepared by compression-molding using a hydraulic press in the following conditions: preheating - 5 min at a temperature of 175 °C, press - 10 min., at a temperature of 175 °C and a pressure of 147 barr and cooling - 20 min. Specimens were prepared from these plates and films for testing of tensile, and thermal (differential scanning calorimetry (DSC)) properties, water vapor transmission rate, antimicrobial and antioxidant activity.
It is noted that the addition of the BYP-P4101 additive to the PLA plasticized formulations containing modified chitosan has the effect of increasing the antimicrobial activity (log reduction of 4.42 to 4.71 against E. coli) - Table 5 - Example no. 2 and Example no. 3, the reduction of tensile strength PLA of biocomposites -14% in the case of the incorporation of 1% BYK and ~ 48% in the case of the incorporation of 3% BYK respectively, compared to neat PLA (Table 8) - Example 2 and Example 3, and also, to improve the water vapor transmission rate (13.76 g/m2/ 24 h in the case of biocomposite containing 3% BYK) - Table 9 - Example 3. Also, the glass transition temperature (Tg), the melting temperature (Tm) and the degree of crystallinity of the PLA (Xc) decrease with the addition of the BYK additive - Table 10 - Example no. 2 and Example no. 3. Biocomposite containing the BYK-P 4101 additive at 1% concentration has a higher antioxidant activity (percent inhibition of 29,9%) compared to the other samples - Table 7 - Example no. 2.
Exemples no. 4-6:
39.2 g PLA is melt mix with 6.86 g Lapoll08 plasticizer on a Brabefider Plastograph, equipped with a mixing cuve of 50 cm3 at a temperature of 170 ± 5 0 C, at 60 rpm for 2 minutes. Then, 2.94 g PEG BioUltra 4000, 0.52 ml vitamin E and 0.5 g chitosan modified with rosehip oil cold pressed were added to the molten mixture. Melt mixing is continued up to 6 minutes.
In the Example no. 5, 0.25 g BYK-P4101 and 0.5 g HPS additives respectively are added to the composition of Example no. 4, so that the mass ratio between the PLA and plasticizers is 80:20 and those between LAPOL 108 and PEG BioULTRA 4000 is 70:30.
Exemple no. 6 is considered as reference for Exemples no. 4 and 5.
The composition based on PLA, plasticizers, chitosan modified with rosehip oil cold pressed and B YK-P4104 and HPS additives, in weight percent, is shown in Table 2.
Table 2 - Composition of obtained biocomposites and plasticized PLA according to Exemples no.
4-6
Figure imgf000011_0001
The same procedure described in Examples no. 1-3 was used for preparation and testing of specimens.
Investigated biocomposites (Example no. 5 and Example no. 4) record a log reduction of 1.5 - 1.8 against E. coli and of 2.2 - 3 against S. aureus - Table 5 and Table 6. In comparison with the reference (Example no. 6), the sample containing modified chitosan with rosehip oil cold pressed shows a tensile strength greater (29 MPa)- Exemple no. 4, while the sample containing HPS and BYK additives shows a decrease in tensile strength (17 MPa) and a higher antioxidant activity (23,53%) - Exemple no. 5. For those two samples (Example no. 4 and Example no. 5), compared with the reference, the elongation at break decreases significantly, from 45% to ~ 3% - Table 8, the cold crystallization does not occur, the glass transition temperature shows a higher value (57-59 °C) and the degree of crystallinity decreases (33-34%) - Table 10.
Exemples no. 7-11:
39.2 g PLA is melt mix with 5.88 g Lapol 108 plasticizer on a Brabender Plastograph, equipped with a mixing cuve of 50 cm3 at a temperature of 170 ± 5 0 C, at 60 rpm for 2 minutes. Then, 3.92 g PEG BioUltra 4000, 0.52 ml vitamin E and 0.5 g chitosan modified with rosehip oil cold pressed were added to the molten mixture. Melt mixing is continued up to 6 minutes.
In the Examples no. 8-10, chitosan is modified with rosehip oil and purified sodium montmorillonite (C30B) in following quantities: 0.5 g, 1 g and 1.5 g respectively, so that the mass ratio between the PLA and plasticizers is 80:20 and those between LAPOL 108 and PEG BioULTRA 4000 is 60:40.
Exemple no. 11 is considered as reference for Exemples no. 7-10.
The composition based on PLA, plasticizers, chitosan modified with rosehip oil cold pressed and sodium montmorillonite, in weight percent, is shown in Table 3.
Table 3 - Composition of obtained biocomposites and plasticized PLA according to Exemples no.
7-11
Figure imgf000012_0001
* modified chitosan with rosehip oil and C30B
The same procedure described in Examples no. 1-3 was used for preparation and testing of specimens.
Biocomposites containing both chitosan modified with rosehip oil cold pressed and montmorillonite in the percentage of 1-3%, show a significant antimicrobial activity against E. coli (logarithmic reduction of 4.87-5.83) - Examples no. 8-10 - Table 5. Compared to reference, (Example no. 11) for which the tensile strength is 28 MPa, the tensile strength decreases with incorporation of 1% chitosan modified with rosehip oil cold pressed and sodium montmorillonite respectively - Exemples no. 7 and 8 (21-23 MPa), but with increasing of the antimicrobial agent content modified with sodium montmorillonite - Examples no. 9 and 10, this property increases (24- 31 MPa) as a result of the improving compatibility between the polymer matrix and modified chitosan - Table 8, the water vapor permeability increases (42-44 g/m2/24 h) - Table 9. The samples (Exemples no. 7-10) show a melting temperature around 151-152 °C, accompanied by a small shoulder (144-146 °C) due to the melting of different types of crystallites and a cold crystallization temperature (102-107 °C) higher than the reference. The degree of crystallinity is lower (30-32%) compared to reference (34%) - Examples no. 7, 8 and 10. Adding of 2% chitosan modified with oil rosehip and montmorillonite has an effect of nucleations (increase of the degree of crystallinity) - Exemple no. 9. Biocomposite containing 3% modified chitosan leads to lowering of Tg (47.7 0 C) - Example no. 10, since those with 2% and3 % modified chitosan respectively, show an increase of the Tg with respect to reference - Table 10.
Exemples no. 12-17:
39.2 g PLA is melt mix with 3.92 g Lapol 108 plasticizer on a Brabender Plastograph, equipped with a mixing cuve of 50 cm at a temperature of 170 ± 5 ° C, at 60 rpm for 2 minutes. Then, 5.88 g PEG BioUltra 4000, 0.52 ml vitamin E and 0.5 g chitosan modified with rosehip oil cold pressed were added to the molten mixture. Melt mixing is continued up to 6 minutes.
In the Examples no. 13 and 14, chitosan is modified with rosehip oil and purified sodium montmorillonite (C30B) in following quantities: 0.5 g and 1 g respectively and added to the composition from Exemple 12, so that the mass ratio between the PLA and plasticizers is 80:20 and those between LAPOL 108 and PEG BioULTRA 4000 is 40:60.
Than the composition from Exemple no. 12, in Exemples no. 13 and 14, 0.25 g BY P-4101 and HPS additives in amount of 0.5 g and 1 g respectively are added.
Exemple no. 17 is considered as reference for Exemples no. 12-16.
The composition based on PLA, plasticizers, chitosan modified with rosehip oil cold pressed and sodium montmorillonite, in weight percent, is shown in Table 4.
Table 4 - Composition of obtained biocomposites and plasticized PLA according to Exemples no.
12-17
Figure imgf000013_0001
Exemple 15 77.2 7.72 1 1.58 1 1 1 0.5
Exemple 16 76.4 7.64 11.46 1 1 2 0.5
Exemple 17 79.2 7.92 1 1.88 - 1 - -
*modified chitosan with rosehip oil and C30B
The same procedure described in Examples no. 1-3 was used for preparation and testing of specimens.
As compared to the reference (Example no. 17), the tensile strength decreased with ~ 50% for all samples and the elongation at break is in the range of 5-12% (Table 8) - Examples no. 12-16, and the water vapor transmission rate does not differ significantly. The antimicrobial activity is in the range of 1.3 - 3.5 log reduction against E. coli and 2.2-3.1 against S. aureus respectively (Table 5 and Table 6) - Examples 12-16. The glass transition temperature increases than reference with adding of modified chitosan, which has an effect to increase the degree of crystallinity of PLA (Table 10) - Examples 12-16.
Analysis of PLA-based active biocompositions and modified chitosan
Investigation methods and obtained results
Antimicrobial activity. Antimicrobial activity was performed in accordance with the ISO 22196:2007. The method involve placing a droplet of a suspension of either Escherichia coli ATCC 8739 or Staphylococcus aureus ATCC 6538 directly onto the material surface (50 x 50 mm) being tested. Each test specimen; treated and untreated was prepared in a separate sterile Petri dish with the test surface uppermost and 0.4 ml of the test inoculum with concentration between 2.5 xlO5 cells/ml and lOxlO5 cells/ml was pipetted onto the test surface. The test inoculum was covered with a piece of neutral film (without anti-bacterial properties, 40 x 40 mm) and gently pressed down on the film so that the test inoculum spreads to the edges. Immediately after inoculation, half of the untreated test specimens were processed by adding 10 ml of SCDLP (soybean casein digest broth with lecithin and polyoxyethylene sorbitan monooleate) broth to the Petri dish containing the test specimen and number of viable bacterial cells counted on Plate count agar. This value (U0) was used to determine the recovery rate of the bacteria from the test specimens from this patent. After the specimen; treated and untreated was inoculated and the cover film applied, the lid of the Petri dish was placed. After 24 hour incubation at 35 °C and > 90 % relative humidity ( H), the bacterial suspension was released from between the coverslip-test sample sandwich and the number of viable bacterial cells that had survived was determined for treated (At) and untreated specimen (Ut).
When the conditions for a valid test are satisfied, the test is deemed valid and the antibacterial activity was calculated using Equation (1). R = (Ut - Uo) - (At - Uo) = Ut - A, (1)
Where:
R is the antibacterial activity;
Uo is the average of the common logarithm of the number of viable bacteria, in cells/cm2, recovered from the untreated test specimens immediately after inoculation;
Ut is the average of the common logarithm of the number of viable bacteria, in cells/cm2, recovered from the untreated test specimens after 24 h;
At is the average of the common logarithm of the number of viable bacteria, in cells/cm2, recovered from the treated test specimens after 24 h.
Antibacterial effect of the PLA-based modified chitosan on the E. coli and S. aureus is shown in Table 5 and Table 6.
Determination of antioxidant activity by measuring the ability of inhibiting the DPPH radical (2,2-diphenyI-l-picrilhidrazil)
To carry out the test were used ~ 250 mg of sample, which was kept in a vessel containing 10 ml of methanol under stirring for 24 hours. From the methanolic solution obtained from each sample 0.2 ml were extracted and mixed with 2 ml of DPPH solution (2 x 10"4 mol 1). It was used as a control, a mixture of 0.2 ml methanolic solution which was mixed with 2 ml of DPPH solution. The mixtures were left for 30 minutes at room temperature in the dark, after which the absorbance was measured at 515 nm. The radical deactivation activity was calculated using the following equation:
%RSA = x l OO (2)
Where:% RSA is the procentual activity of the radical, Acontroi is the absorbance of DPPH methanolic solution and Asampie is the absorbance of the sample.
The results are presented in Table 7.
Tensile properties. The tensile properties (tensile strength, elongation at break, the Young's modulus) were determined according to EN ISO 527-2:201 1 using an Instron 3345 tester (USA) on specimens with thickness of 1 mm and length of 40 mm. Test machine operated at a crosshead speed of 10 mm/min. At least five specimens were tested for each composition and the average value is reported in Table 8. The influence of plasticizer content on the tensile properties of PLA- based active biocompositions and modified chitosan with respect to plasticized PLA is shown in Figures 5-7. Water vapor transmission rate. Water vapor transmission rate (WVTR) of the samples was determined with PBI-Dansensor L 80-5000, at a temperature of 23 °C, 85 % humidity (RH) and atmospheric pressure. The specimens with dimensions (108x108x0.1) mm were used for testing of permeability. The values obtained in comparison with neat PLA are shown in Table 9.
Differential scanning calorimetry (DSC) measurements. Thermal analysis of samples was carried out on a DSC analyzer (823e Mettler Toledo) in the range of 35-190 °C and at a heating rate of 10 °C /min. From DSC thermograms, first run, glass transition temperature (Tg), crystallization temperature (Tcc), crystallization enthalpy (AHCC) melting temperature (Tm) and melting enthalpy (AHm) were determined. The degree of crystallinity (Xc) was calculated by dividing the melting enthalpy of the specimens, AHm (J/g) to the enthalpy value for a theoretically 100% crystalline PLA (AHm° = 93.1 J/g). The weight fraction of PLA from each sample was used for Xc calculation.
DSC thermograms for PLA-based active biocomposites compared to reference are illustrated in Figures 8-11. DSC parameters are summarized in Table 10.
In all characterizations, for comparative purpose, it has included the value obtained for pure PLA.
All the formulations shown in Examples 1....17 show antimicrobial activity against E. Coli and S. Aureus. There is not found any antibacterial effect of neat PLA (negative results presented in Table 5 and Table 6). For E. coli strain, PLA-based biocomposites showed a greater antimicrobial effect than in the case of 51 aureus. For biocomposites containing modified chitosan and plasticizers in the ratios of 100/0, 70/30 and 60/40 respectively, the antimicrobial effect increased compared to reference samples against E. coli (Example 1, Example 6, Example 11 and Example 17) - Table 5.
Table 5 - Log10 reduction of Escherichia coli ATCC 8739 in contact tests with PLA-based biocomposites, plastified PLA and neat PLA
Uo u, A, R= (Ut- At)
PLA 3.58 3.85 6.07 -2.22
Exemple 1 3.97 5.04 2.62 2.42 (> 99%)
Exemple 2 3.78 5.94 1.52 4.42 (> 99.9%)
Exemple 3 3.78 5.94 1.23 4.71 (> 99.9%)
Exemple 4 4.3 2.1 0.3 1.8 (> 90%)
Exemple 5 4.3 2.1 0.6 1.5 (> 90%)
Exemple 6 4.3 2.1 0.8 1.3 (> 90%)
Exemple 7 3.82 1.99 1.42 0.57 (< 90%)
Exemple 8 3.78 5.94 1.07 4.87 (> 99.9%)
Exemple 9 3.78 5.94 0.11 5.83 (> 99.9%)
Exemple 10 3.78 5.94 0.71 5.23 (> 99.9%)
Exemple 11 4.19 2.55 0.88 1.67 (> 90%)
Exemple 12 3.8 4.3 2.1 2.2 (> 90%)
Exemple 13 3.8 4.3 0.8 3.5 (> 99.9%)
Exemple 14 3.6 2.7 0.4 2.3 (> 99%)
Exemple 15 3.6 2.7 0.8 1.9 (> 90%) Exemple 16 3.6 2.7 0.4 2.3 (> 99%)
Exemple 17 3.8 4.3 1.5 2.8 (> 90%)
Adding of chitosan modified with rosehip oil cold pressed and montmorillonite (1-3%) to plasticized PLA containing plasticizers in a ratio of 60:40 Lapoll08 to PEG led to an increased antimicrobial effect against E. coli of about 5 log units compared to the untreated PLA (Example no. 8, Example no. 9 and Example no. 10). An increase of about 4 log units was recorded in the case of biocomposites containing only Lapol 108 (20%) and BYK-P4101 additive (1% and 3%) treated with E. coli (Example no. 2 and Example no. 3). The greatest antimicrobial effect against S. aureus was obtained by the biocomposites with modified chitosan and a plasticizers ratio Lapol 108:PEG of 40:60 (Example no. 12 and Example no. 13) - Table 6.
Table 6 - Log10 reduction of Staphylococcus aureus ATCC 6538 in contact tests with PLA-based biocomposites, plastified PLA and neat PLA
Figure imgf000017_0001
Table 7 shows that the antioxidant activity decreases with increasing of ratio between plasticizers and the biocomposites containing the plasticizers ratio of 40:60 and modified chitosan have a higher antioxidant activity (Example no. 13, Example no. 15 and Example no. 16).
Table 7 - Antioxidant activity for PLA-based biocomposites, plastified PLA and neat PLA
Figure imgf000017_0002
Exemple 9 24.02
Exemple 10 26.96
Exemple 11 26.35
Exemple 12 28.92
Exemple 13 51.96
Exemple 14 31.86
Exemple 15 41.67
Exemple 16 45.58
Exemple 17 25.98
The introduction of the modified chitosan to the plasticized PLA has the effect of lowering the tensile strength for all biocomposites compared to the value recorded for PLA (69.28 MPa). As a consequence, the Young's modulus dramatically decreased - Figure 7. Looking at Figure 5 and Table 8 it can be observed that the highest values of tensile strength are recorded for biocomposites containing only Lapol 108 as plasticizer and chitosan modified with rosehip oil cold pressed (48-57 MPa) (Example no. 1 and Example no. 2), followed by the biocomposite containing the ratio between plasticizers of 40:60 and 3% chitosan modified with rosehip oil cold pressed and sodium montmorillonite (31.24 MPa) (Example no. 10). By adjusting the mass ratio between PEG and Lapol 108, the elongation at break can has different values, depending on the intended use of the food packaging (Figure 6). Thus, if it is desired to produce flexible packages, then it can pick up the sample containing 40:60 weight ratio between Lapol 108 and PEG without the need to add modified chitosan (Example no. 17, elongation at break of 239 %). This sample shows antimicrobial activity due to the vitamin E content from composition. To obtain rigid packages it can opt for any formulation containing modified chitosan.
Table 8 - Tensile properties of PLA-based biocomposites, plastified PLA and neat PLA
Figure imgf000018_0001
Exemple 15 14.96±4.28 11.3±0.16 1946±68
Exemple 16 14.48±3.02 7.35±1.87 1793±84
Exemple 17 37.6±2.65 239.58±13.57 2130±140
Table 9 shows that with increasing of bioplasticizer content from PLA biocomposites, the water vapor permeability increased, from 15.94 g/m /24 h for the neat PLA to 21.97 g/m2/24 h in the case of ratio between plasticizers of 70/30, to 28.09 g/m2/24 h when the ratio between plasticizers is 60/40 and to 37.45 g/m2/24 h respectively if the plasticizers ratio is 40/60 (Example no. 6, Example no. 11, Example no. 17).
Table 9 - Water vapor permeability of PLA-based biocomposites, plastified PLA and neat PLA
Figure imgf000019_0001
This increase in barrier property is correlated with the decrease in the degree of crystallinity reported in Table 10. The introduction of the modified chitosan into the plasticized PLA matrix leads to an increased of water vapor permeability with respect to reference, which is due to the high affinity of chitosan for water [31]. It is noted that BYK-P 4101 additive has an improving effect of the water vapor permeability (Example no. 2 and Example no. 3) compared to the samples without additives, while the HPS additive increased the barrier to water vapor (Example no. 5, Example no. 15 and Example no. 16).
Table 10 - Thermal parameters evaluated from DSC thermograms for PLA-based biocomposites,.;
plastified PLA and neat PLA
Figure imgf000019_0002
PLA 65.2 - - 18.1 155.7 19.4
Exemple 1 54.7 12.1 115.9 10.9 149.6 14.9
Exemple 2 52.4 10.2 120.6 5.4 147.8 7.5
Exemple 3 50.7 3.7 126.0 3.0 148.7 4.3
Exemple 4 57.6 - - 24.7 149.8 33.8
153.5
Exemple 5 59.1 - - 24.6 145.3 34.2
Exemple 6 54.3 15.7 92.9 26.3 149.4 35.6
Exemple 7 48.4 17.9 102.8 22.0 151.4 30.1
144.8
Exemple 8 49.2 19.6 107.3 23.7 151.2 32.4
145.5
Exemple 9 49.0 21.7 106.4 26.1 150.9 36.1
145.2
Exemple 10 47.7 22.2 105.0 21.8 152.6 30.4
146.0
Exemple 11 48.5 16.8 93.5 25.3 152.2 34.3
142.8
Exemple 12 56.3 - - 29.9 151.7 40.9
Exemple 13 58.3 - - 29.1 151.2 39.8
Exemple 14 60.3 - - 23.8 152.7 32.9
Exemple 15 55.6 - - 26.2 151.1 36.4
Exemple 16 55.3 - - 23.9 151.9 33.6
Exemple 17 45.7 17.3 79.6 22.9 149.9 31.0
138.5
Analysing the DSC parameters (Table 10) PLA is found that the addition of plasticizers leads to lower glass transition temperature, in good corellation with the increasing of plasticizer content (Example no. 6, Example no. 1 1 and Example no. 17) than non-plasticized PLA. Incorporation of modified chitosan led to the restricting of macromolecular chains mobility and melting peaks are situated at higher melting temperatures against reference samples, but smaller than that of pure PLA. The presence of modified chitosan into PLA matrix where the ratio between plasticizers is 40:60 increases the activity of PLA to crystallize, the degree of crystallization having higher values than reference (32-40%) - Examples no. 12-16.
60
£ 40
σ>
c
S>
n 30
CD
20
10
Figure imgf000021_0001
Figure 5. Plasticizer content influence on the tensile strength at break of the PLA-based active biocomposites and modified chitosan. The caption indicates the ratio between Lapol 108/PEG BioULTRA 4000 plasticizers
Figure imgf000021_0002
ssssssss#sss/sss
Figure 6. Plasticizer content influence on the elongation at break of the PLA-based active biocomposites and modified chitosan. The caption indicates the ratio between Lapol 108 PEG BioULTRA 4000 plasticizers
Figure imgf000022_0001
Figure 7. Plasticizer content influence on the Young modulus of the PLA-based active biocomposites and modified chitosan. The caption indicates the ratio between Lapol 108/PEG BioULTRA 4000 plasticizers
Figure imgf000022_0002
Figure 8. DSC thermograms for PLA-based active biocomposites (Exemples no. 1...3) - Exemple 4
■ Exemple 5]
- Exemple 6[
-7
40 60 80 100 120 140 160 180
Temperature ( C)
Figure 9. DSC thermograms for PLA-based active biocomposites compared to reference (Exemples no. 4...6)
Figure imgf000023_0001
Temperature (°C)
Figure 10. DSC thermograms for PLA-based active biocomposites compared to reference
(Exemples no. 7...11)
5
o
as
ω ■Exemple 121
X
- Exemple 13
-7-1 - Exemple 14
-8 - Exemple 15
- Exemple 16
-9 - Exemple 17
40 80 100 120 140
Temperature (°C)
Figure 11. DSC thermograms for PLA-based active biocomposites compared to reference
(Exemples no. 12...17)

Claims

PLA - BASED ACTIVE AND DEGRADABLE BIOCOMPOSITES FOR FOOD PACKAGING CLAIMS
1. Polymer biocomposites characterized in that as, are consist of a mixture of: 76 to 79.2% PLA Ingeo type 2003D, LAPOL 108 as masterbatch from 7.64 to 19.6%, PEG 4000 BioULTRA 5.79 to 11.88%, chitosan average molecular weight modified by encapsulating of rosehip oil obtained by cold pressing of the seeds rosehip and/or Cloisite C30B 0-3%, vitamin El%, BYP P-4101 0.5-3 % and HPS 0-2% additive (the percentages being expressed in weight percent), incorporated additives having the effect of improving prelucrability, antimicrobial activity and barrier properties.
2. Polymer Biocomposites as defined in claim 1, characterized in that as, the mass ratio between PLA and plasticizers is 80/20, and between LAPOL 108 and PEG BioUltra 4000 plasticizers is 100 ... 40/0 ... 60.
3. Biocomposites polymer as defined in any one of claims 1-2, characterized in that as, the antimicrobial agent is chitosan modified by encapsulating of the rosehip oil and / or Cloisite C30B.
4. Biocomposites polymer as defined in any one of claims 1-2, characterized in that as, the polymeric additive to improve the properties of the barrier is BYK-P 4101.
5. Process for obtaining a biocomposites polymer as defined in claim 1, characterized in that as, the raw material is processed in the melt at a temperature of 170 ± 5 ° C, mixing time of 6 minutes and a rotational speed of screw of 60 rpm followed by hot pressing at 175 °C and a pressure of 147 bar, from which films with dimensions of 200x200x0,1 mm and plates with dimensions of 150x150x1 mm are obtained, having a very good antimicrobial activity which consists of a logarithmic reduction of 1.3 to 5.8 against E. coli and of 0.39 to 3.1 in the case of exposure to S. aureus, which corresponds to an inhibition of the development of these gram-negative and gram- positive bacteria respectively above 90 % and an antioxidant activity between 23,55-51,96%, tensile properties > 10 MPa and elongation at break suitable for making rigid or flexible antimicrobial food packaging.
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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109354724A (en) * 2018-09-26 2019-02-19 蚌埠市国药农业科技有限公司 A kind of degradable moisturizing mulch and preparation method thereof
CN110218427A (en) * 2019-06-28 2019-09-10 王新华 A kind of high strength easy-to-degrade antibacterial environment protection poly-lactic acid material
CN110408039A (en) * 2019-08-19 2019-11-05 陕西理工大学 A kind of preparation method of the miniature product of high-intensity and high-tenacity polylactic acid
CN111019099A (en) * 2019-12-02 2020-04-17 华南理工大学 Chitosan grafted polylactic acid copolymer and preparation method and application thereof
CN112625411A (en) * 2020-12-10 2021-04-09 好维股份有限公司 Biodegradable antibacterial toothbrush and production process thereof
CN113354930A (en) * 2021-06-08 2021-09-07 南京财经大学 Degradable preservative film and preparation method and application thereof
CN113817205A (en) * 2021-09-29 2021-12-21 上海海洋大学 Photocatalytic polylactic acid antibacterial film and preparation method and application thereof
CN113861642A (en) * 2021-09-16 2021-12-31 郑州大学 PLA/PBF/POE-g-GMA/ZnO composite material for antibacterial food packaging and preparation thereof
CN114907678A (en) * 2022-05-06 2022-08-16 青岛科技大学 pH response polylactic acid-based composite membrane and preparation method thereof
CN115960446A (en) * 2022-12-27 2023-04-14 浙江农林大学 Preparation method of essential oil/carboxylated nanocellulose/polylactic acid packaging film
CN117511159A (en) * 2024-01-05 2024-02-06 湖南大道新材料有限公司 Cosmetic dry-wet separation packaging bag

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5908918A (en) * 1996-07-17 1999-06-01 Chronopol, Inc. Impact modified polylactide
WO2013119450A1 (en) * 2012-02-10 2013-08-15 The United States Of America, As Represented By The Secretary Of Agriculture Bioderived compatibilizer for biopolymers

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5908918A (en) * 1996-07-17 1999-06-01 Chronopol, Inc. Impact modified polylactide
WO2013119450A1 (en) * 2012-02-10 2013-08-15 The United States Of America, As Represented By The Secretary Of Agriculture Bioderived compatibilizer for biopolymers

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
"Polymeric processing additive to improve the processing properties and the mechanical resistance of thermoplastic compounds", BYK ADDITIVES & INSTRUMENTS, 2015, Retrieved from the Internet <URL:http://www.uni-trading.com/sub/support/tds.msds/additive/BYK/BYK_etc/TDS/BYK-P4101%20TDS(EN).pdf> *
KUORWELL K. KUORWELL ET AL.: "Review of Mechanical Properties, Migration, and Potential Applications in Active Food Packaging Systems Nanoclays and NanoSilver", COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, vol. 14, 2014, pages 411 - 430 *
MASSIMILIANO BARLETTA ET AL.: "Graphene-modified Poly(Lactic Acid) for packaging: Material formulation, processing, and performance", JOURNAL OF APPLIED POLYMER SCIENCE, 2015, pages 42252 *
PAMELA PITTARELLA ET AL.: "Vitamin E Acetate Addition to Poly(D,L)Lactic Acid Modifies Its Mechanical Behavior Without Affecting Biocompatibility", JOURNAL OF APPLIED POLYMER SCIENCE, 2014, pages 39970, XP055496917 *
PAUL ALEXANDRU POPESCU ET AL.: "Biodegradation behaviour of PLA/chitosan composites in natural soil", ISEKI_FOOD ASSOCIATION, July 2016 (2016-07-01), pages 1 - 2, XP055496914 *

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CN110218427A (en) * 2019-06-28 2019-09-10 王新华 A kind of high strength easy-to-degrade antibacterial environment protection poly-lactic acid material
CN110408039B (en) * 2019-08-19 2021-12-03 陕西理工大学 Preparation method of high-strength high-toughness polylactic acid miniature product
CN110408039A (en) * 2019-08-19 2019-11-05 陕西理工大学 A kind of preparation method of the miniature product of high-intensity and high-tenacity polylactic acid
CN111019099A (en) * 2019-12-02 2020-04-17 华南理工大学 Chitosan grafted polylactic acid copolymer and preparation method and application thereof
CN111019099B (en) * 2019-12-02 2021-12-21 华南理工大学 Chitosan grafted polylactic acid copolymer and preparation method and application thereof
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CN113817205A (en) * 2021-09-29 2021-12-21 上海海洋大学 Photocatalytic polylactic acid antibacterial film and preparation method and application thereof
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