BRPI0804422A2 - process for the production of hybrid reinforced polymeric materials and their applications - Google Patents

Abstract

The present invention relates to a process for producing reinforced hybrid polymeric materials and their applications. The procedure of the invention contemplates the incorporation of preformed polystyrene into submicron or nanometric size potimeric particles obtained in polymerization processes in dispersed medium. The process is preferably, but not exclusively, characterized by the use of post-consumption polystyrene or polystyrene residues via dissolution in suitable monomer or mixture of monomers, preparation of a hybrid polymer-monomer droplet emulsion and subsequent homogenization of this emulsion according to high-tech techniques. shear, and polymerization of the monomers contained in the hybrid drops. The process disclosed in this invention allows the incorporation of more than 40% w / w post consumer polystyrene into polymeric matrices, the preparation of stable polymer-monomer hybrid droplets and the obtaining of synthesized reinforced materials suitable for various industrial applications.

Description

PROCESS FOR PRODUCTION OF ENHANCED HYBRID POLYMERIC MATERIALS AND THEIR APPLICATIONS

Technical Field

The present invention relates to a process for producing polymer-polymer reinforced hybrid materials and their applications. The method of the invention basically consists in the incorporation of preformed polystyrene into submicron or nanometric polymer particles obtained via dispersed system polymerization, where the preformed polystyrene confers the reinforced hybrid characteristic of the material produced. The process is characterized by the preferential but not exclusive use of post-consumption polystyrene. The processor disclosed in this patent is a novel method for polystyrene recycling, where such recycled materials may be employed directly after disposal, or alternatively after conventional separation processes have been subjected to them. The process is further characterized by the dissolution of post-consumption polystyrene by minus an unsaturated ethylenic monomer or mixtures of suitable unsaturated ethylenic monomers, preparation of a polymer-monomer gotash hybrid emulsion, emulsion homogenization with high shear techniques, and subsequent polymerization of the hybrid inlets. It is the object of the present patent application to allow the incorporation of more than 40% w / w post-consumption polystyrene in polymeric matrices, preparation of stable polymer-monomer hybrid droplets and suitable for various materials. industrial applications.

State of the Art

For various reasons it is desirable to incorporate a second polymeric material into existing aqueous polymer dispersions. In many applications, these hybrid materials have improved and reinforcing characteristics when compared to the simple mixture of different materials. Synthesis of aqueous polymeric dispersions via mini-emulsion polymerization has been known for several years and the technique has several advantages compared to conventional dispersed system polymerization techniques. For example, the mini-emulsion polymerization technique allows the incorporation or encapsulation of hydrophobic components in polymers during polymerization and is a valuable tool for the production of hybrid materials. In addition to the unsaturated ethylene monomer, or unsaturated ethylenic demonomer mixtures, water and surfactants, the miniemulsion process contains in its formulation an additional compound to stabilize the small droplets formed during the homogenization process before and after the polymerization process. Such an additional compound or compost is usually hydrophobic materials with low or no water solubility and good monomer miscibility.

US Pat. 4,113,687 discloses a process for the production of vinyl chloride mini emulsions. The disclosed process requires the use of plasticizers for the stabilization of submicron droplets, which stabilization, which according to the inventors cannot be conferred by the use of high molecular weight trypsets. 4,070,323 and US Pat. 4,177,177 relates methods based on dissolving polymers and co-stabilizers in a solvent, followed by solvent elimination and recovery according to standard processes. The use of polymers as potential hydrophobic components is disclosed in US Pat. 5,686,518 to the inventors Fontenot, Schork and Reimers. According to the inventors, the use of non-volatile compounds offers a distinct advantage over traditional volatile co-stabilizers as they must be eliminated from the final product. Pure polymers are employed in amounts less than 5% w / w with respect to demonomer weight.

The mini-emulsion polymerization technique has been described as suitable for incorporating materials into polymeric matrices. In U.S. Patent Bhattacharjee and Schrock disclose in US Pat. US2002 / 0177654 a process for the production of hybrid particles. According to the described process, a pure polymer is initially synthesized for the specific purpose of the process, then the polymer is dissolved in a monomer. This solution should have low viscosity, typically less than 1 Pa.s, which is the maximum working limit. The process is further characterized by subsequent polymerization. The American invention US 2007/0218089 A1 issued to BASF Aktiengesellschaft discloses a process for incorporating polymeric particle effect materials using the mini emulsion polymerization technique. According to the process, the effects materials are characterized as substances that confer stability to UV radiation and resistance to light and heat. Processon is not characterized by the intentional production of a preformed polymer for the production of hybrid particles. The process disclosed in US Pat. No. US2005 / 0T76896 A1 employs liquid particle-emulsified particles for the encapsulation of chemical compounds. According to the document, encapsulation would not be feasible via the use of other polymerization techniques. The stabilization of liquid particles is performed with the presence of low molecular weight oil-soluble compounds.

Following current practice in the chemical industry, all processes in the current state of the art employ pure or coarse chemicals. Impurities are known to severely affect chemical synthesis, resulting in longer reaction times, inhibition times, out-of-specification material production, unsafe operating conditions, and other negative impacts.

Polystyrene is used in large quantities because of its characteristics, such as low cost, low thermal conductivity and good shock resistance. Expanded polystyrene is a widely used material in the construction sector, mainly for thermal insulation, and in the packaging industry. The material is produced with pentane, or another blowing agent known in the prior art, inserted into the polystyrene matrix, which is then steam heated to form expanded polystyrene. The residue from these materials and the production of polystyrene and expanded polystyrene, more specifically expanded polystyrene, due to their low density, are bulky, making transportation and subsequent disposal one of the major challenges for the plastics family.

There are several alternatives to minimize the negative impact of polystyrene residue on the environment. Remediation via the incineration process in advanced incineration systems can produce from 8.2 MJ to 8.6 MJ of energy per 1.0 kg of tailings. However, it is known that the characteristics may interfere with the incinerator combustion process and may also cause the production of highly toxic gases.

Consumer plastic materials are complex compositions including one or more polymers and various additives and are rarely pure materials. Some types of expanded polystyrene contain flame retardants based on brominated compounds, and blowing agents, among other additives. These materials when incinerated can cause extremely toxic degassing. Consequently, residues from polystyrene, and more specifically expanded polystyrene, should initially be subjected to a process of volume reduction, separation of impurities, elimination of additives and finally regeneration of polystyrene. Volume reduction can be performed by thermo-mechanical decompression treatment. However, these processes are known to cause degradation of recycled material. Alternative methods for volume reduction and polystyrene recycling according to the current state of the art involve polymer dissolution in organic solvents. WO2007 / 009553 A1 discloses a process similar to that described in US Pat. 5,232,954 and German DE 10207336, in which the polymeric residue is dissolved in a system consisting of a solvent and a non-solvent. The process requires multiple steps. Initially, volume reduction, separation of insoluble materials, polymer precipitation, subsequent separation, washing and drying of precipitated polystyrene occur.

The present inventor has found that post-consumer polystyrene can be completely recycled into polymer particles using the mini emulsion technique. Surprisingly, the process leads to the production of superior performing polymer-polymer hybrid departments. Thus, the present inventor — developed a new method for reducing polystyrene and expanded polystyrene and for the production of reinforced hybrid materials.

Summary of the Invention

On the one hand, the invention disclosed herein relates to a process for the production of polymeric dispersions, and their products obtained in production, comprising: (a) Dissolving post-consumer polystyrene or expanded polystyrene into an unsaturated ethylene monomer or mixtures of unsaturated monomers;

(b) Formation of a mixture of (a) with another unsaturated ethylene monomer or monomers, in a ratio defined according to the desired final application;

(c) Dispersing the mixture prepared in (b) into an aqueous system containing a suitable surface active substance;

(d) subjecting the aqueous dispersion prepared under (c) to conditions sufficient to prepare micro- or nanometric drops of the hybrid polymer-monomer organic phase;

(e) subjecting the dispersion formed in (d) to conditions suitable for polymerization of the monomer (s), forming a dispersion of polymeric particles, containing a polymer-polymer hybrid system with an average particle size preferably less than 1000 nm;

On the other hand, the present invention is a new process for post-consumer expanded polystyrene or expanded polystyrene recycling, where polymer-polymer hybrid materials are produced with concentrations greater than 40% w / w of the material to be recycled over the total weight of polymeric material via polymerization. in dispersed system.-

In a third aspect, this invention is a process for producing polymer-polymer hybrid materials with enhanced properties that can be applied in various fields such as paint, paper and board coating, cosmetics, textiles, and other areas and applications. Detailed Description of the Invention

In the following text the invention is described in detail, but not limited to the description.

Post-consumer polystyrene may be any residue containing polystyrene and / or expanded polystyrene. For example, the waste may result from industrial production of the material, waste from granulators and transformers in general, packaging waste obtained from urban collection, expanded polystyrene obtained from agricultural applications, drinking glasses, plates, etc.

Surprisingly, according to the scope of the present invention, post-consumable polystyrene can be used without any specific process for pre-separation of assets such as plasticizers, antioxidants, stabilizers, pigments and flame retardants. Alternatively, post-consumption polystyrene obtained from urban or rural waste may be used after separation of polystyrene from its additives, employing processes known in the art such as selective dissolution followed by deprecipitation.

Operating according to the procedure of the invention, post-consumer polystyrene dissolution is carried out at atmospheric pressure in equipment preferably equipped with a stirring system, condenser and at a temperature typically in the range of 20 ° C to 70 ° C.

Preferably, the temperature is in the range of 30 ° C to 60 ° C. According to the scope of the invention, post-consumer polystyrene may be used as waste, or alternatively after undergoing decompression processes known in the art.

Following the procedure of the invention, post-consumer polystyrene is dissolved in a suitable unsaturated ethylenic monomer or unsaturated ethylenic demonomer mixtures. Suitable unsaturated ethylenic monomers α, (3 include acrylates or alkyl methacrylates (eg methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, isobornyl methacrylate and lauryl methacrylate), polymerizable aromatic compounds (eg styrene, α-methyl styrene, vinyl toluene and tert-butyl styrene), for example polymerizable nitriles , acrylonitrile and methacrylonitrile), rue-curable compounds, α-olefin compounds such as ethylene, vinyl compounds such as vinyl acetate, vinyl propionate and homologues of long chain vinyl esters, vinyl esters, audynylidene vinyl halides, butadiene and isoprene Other ethylenic monomers a, (3 unsaturated are those with fluorine or silicon atoms, such as acryl 1H, 1H, 5H-octafluorpentyl actin and trimethylsilyloxyethyl acrylate.

Preferably, the unsaturated α (3) ethylenic monomers are chosen from the group consisting of styrene, acrylates and methacrylates, vinyl or vinylidene halides, dienes, vinyl esters and mixtures thereof.

Porphipylammonite rociti-7p: The och-nltna nroforonrialmonte in the ammonium intnmnstpor styrene, vinyl acetate, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, butadiene and vinyl chloride.

More preferably, the styrene and acrylate monomers are chosen as unsaturated ethylenic monomers.

The post-consumption polystyrene concentration in the solution ranges from 0.1% to 50% by weight. Preferably, the concentration ranges from 1% to 40% by weight. More preferably, the concentration of post-consumer polystyrene or expanded polystyrene in the range of 10% to 30% by weight. Post-consumer materials may contain insoluble components. These materials, if present, are separated from the polystyrene / monomer solution by techniques. conventional solid / liquid separations such as centrifugation, filtration and decantation.

Upon termination of dissolution of the nomomere post-consumption polystyrene according to the procedure of the present invention, the post-consumption polystyrene / monomer solution is completely mixed with unsaturated ethylene monomer or unsaturated ethylene monomer mixtures. The proportions and compositions of the unsaturated ethylenic monomers are chosen according to the desired final properties of the material to be synthesized, which is widely known to one of ordinary skill in the art.

Suitable unsaturated Î ±, ethylenic monomers include alkyl methacrylates or acrylates (eg methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylate cyclohexyl, 2-ethylhexyl methacrylate, stearyl methacrylate, isobornyl methacrylate and lauryl methacrylate), polymerizable aromatic compounds (e.g. styrene, α-methyl styrene, vinyl toluene and tert-butyl styrene), polymerizable nitrile ( acrylonitrile and methacrylonitrile), polymerizable amide compounds, α-olefin compounds such as ethylene, vinyl compounds such as vinyl acetate, vinyl propionate and homologues of long chain vinyl esters, vinyl esters, vinyl halides or vinylidene, diene compounds such as isadiene butadiene. Other α, β unsaturated ethylenic monomers are those fluorine or silicon atoms, such as 1H, 1H, 5H-octafluorpentyl acrylate and trimethylsiloxyethyl acrylate. Preferably, α, β (unsaturated 3) ethylenic monomers are chosen from the styrene compound set. , acrylates and methacrylates, vinyl or vinylidene halides, dienes, vinyl esters and mixtures thereof. Particularly, the choice is preferably made from styrene, vinyl acetate, methyl acrylate, butyl acrylate, ethyl acrylate, 2-acrylate. ethyl hexyl, butadiene and vinyl chloride.

According to the process disclosed in this patent, the post-consumption polystyrene concentration in the solution ranges from 0.1% to 50% by weight. Preferably, the concentration ranges from 1% to 40% by weight.

More preferably, the concentration of post-consumer polystyrene and / or expanded polystyrene in the range of 10% to 30% by weight.

The post-consumption polystyrene / monomer (s) solution is dispersed in the aqueous phase under conditions such that the post-consumption polystyrene / monomer solution dispersed in the aqueous phase forms hybrid drops with an average droplet size of approximately 1 µm or less. The volume fraction of the dispersed phase, transformed into total solids content after the polymerization process, may vary over a wide range, from slightly over 0.1% of the dispersion to 60% or more. The volume fraction preferably constitutes 20%, even more preferably 30%, and even more preferably approximately 50% of the dispersion volume.

The mixture is subjected to high voltage techniques. Tension is defined as force per unit area. One way to exert tension is through shear. Shear means that the force is such that a layer or plane moves to an adjacent layer or plane. Tension can also be exerted on all sides as a mass-depressing stress, so that the stress is exerted almost shear. Another way to exert tension is by cavitation, which occurs when the pressure within a liquid is reduced to the point of vaporization. The formation and collapse of vapor bubbles occurs with violence in short periods of time, producing strong tension. Another way to apply tension is by employing ultrasonic energy.

In a description of the process according to the present invention, the use of high shear localized equipment is preferable. Even more preferably, high shear mixing is achieved by the use of ultrasound, colloidal mills and / or high pressure homogenizers.

Monomers have a low boiling point at ambient temperature and are preferably added to a post-consumption aqueous polystyrene / monomer dispersion. To utilize such monomers, a vasopressurized is conveniently charged with the post-consumption aqueous polystyrene / monomer dispersion and the vessel is pressurized via the addition of the domonomer. The contents of the pressurized vessel are kept under agitation to facilitate incorporation of the monomer into the hybrid drops. Gaseous monomers, as mentioned within the scope of the present invention, are typically hydrophobic. These compounds diffuse through the aqueous phase to the polystyrenophosphates = consumption / monomer. The subsequent polymerization process is conducted in pressurized reactor.

The temperature used in the process homogenization step according to the invention is generally any temperature between the freezing point and the boiling temperature of the compounds present in the mixture. Suitable temperatures for the formation of demonomer mini emulsions are in the range of 20 to 50 ° C, more preferably in the range of 25 to 40 ° C.

The aqueous phase includes water, and additionally contains a suitable emulsifier or mixture of emulsifiers. Emulsifiers may be any surfactant, soap or the like, widely known in the art. Examples of specific emulsifiers include alkyl sulfates, alkyl sulfosuccinates, alkyl aryl sulfonates, α-olefin sulfonates, quaternary ammonium salts, amine salts, oresine fatty acid salts, nonyl or octyl phenol reaction products with similar ethylene oxide . The proportion of the alkyl chain in the various emulsifiers usually ranges from 8 to 18 carbon atoms. Examples of specific surfactants include sodium lauryl sulfate, sodium sulfosuccinates, sodium comodimethylamyl sulfosuccinate, and similar sodium dodecyl diphenyl disulfonate. The emulsifier concentration is sufficient to obtain a stable aqueous dispersion of polymer. The concentration typically ranges from 0.5 to 5 parts over 100 parts of the total parts of monomer to serpolymerized. An additional list of emulsifiers can be found in McCutcheon's 2001, Emulsifiers and Detergents North AmericanEd. The Manufacturing Confectioner Pub. Co. N.J., USA, 2001, pages 1 to 227.

Droplet degradation is known to be caused by colloidal stability and monomer diffusion from small droplets to larger outlets, a process known as Ostwald degradation. During the mini-emulsion polymerization step degradation is not desired, as its occurrence may result in the formation of heterogeneous polymeric particles and with varying size distribution and chemical composition. The instability caused by the collision from Brown's movement can be prevented by choosing suitable emulsifiers. For best particle stability, a hydrophobic co-stabilizer should be used.

Hydrophobic co-stabilizers used in the process according to the present invention are highly water-insoluble compounds and highly soluble in α, β-unsaturated ethylenic monomers. The hydrophobic co-stabilizer employed according to the invention normally has a water solubility of less than 5.10 ~ 5 g / l, preferably less than 5.10 - 6 g / l (measured at 25 ° C).

Suitable hydrophobic co-stabilizers are hydrocarbons, especially alkanes or cycloalkanes, containing at least 12 carbon atoms (eg hexadecane and octadecane), long chain alcohols (eg hexadecanol or octadecanol), halogenated hydrocarbons, organosilicon compounds, long chain esters , oils, such as vegetable oils (eg deoliva olive oil), hydrophobic dyes, protected isocyanates, and also polymerization, polycondensation or polyaddition polymeroligers. The use of polymeric co-stabilizers is described, for example, in USPat. 5,686,518.

According to a specific description of the process according to the patent, a hydrophobic co-stabilizer may also be used alone, or in addition to a non-reactive co-stabilizer. Hydrophobic pig stabilizers are understood to be co-stabilizers that may participate in the subsequent polymerization process. Examples of such compounds are the hydrophobic compounds of stearyl acrylate (co) monomers and other long chain (meta) acrylates, chain transfer agents, comododecyl mercaptan, ocetadecyl mercaptan and other long chain mercaptans, and hydrophobic primers type 2,5- dimethyl-2-5-di (2-ethylhexanoylperoxy) hexane and other (hydro) peroxides or long chain azode initiators.

The hydrophobic co-stabilizer used in the process according to the invention is preferably chosen from alkanes or alcohols containing 12 to 24 carbon atoms, especially hexadecane, or from acrylates containing 18 to 22 carbon atoms and mixtures thereof. A deacrylate mixture containing 18 to 22 carbon atoms is marketed under the name Norsocryl by Atofina.

The hydrophobic co-stabilizer is typically employed in concentrations in the range 0.05 to 40 wt%, preferably in the range 0.1 to 10 wt%, and most preferably in the range 0.2 to 5 wt%, based on in the total weight of the mixture prepared in step (a) of the process according to this invention. In the specific case where (co) monomers as described above are employed as hydrophobic co-stabilizing compounds, their concentration may be up to 70% by weight based on the total amount of post-consumption polystyrene / monomer solution.

When the hydrophobic co-stabilizer is not a (co) monomer, the hydrophobic co-stabilizer is preferably added in amounts ranging from 0.1 to 10 wt%, more preferably from 0.2 to 8 wt% and even more preferably in the range. 0.5 to 5% by weight based on total mass of polystyrene / monomer solution. Surprisingly, in the process according to the invention, the presence of hydrophobic co-stabilizers can be completely eliminated. The inventor has found that mini-emulsions can be prepared by employing only post-consumer polystyrene according to the most recommended procedure of the waterproof process. The essential difference with current state of the art processes is the surprising way in which stable mini emulsions can be generated employing high concentrations of post-consumer polystyrene.

In a description of the process according to this invention, the monomer (s) present within the hybrid drops is polymerized. The monomer (s) is normally polymerized. (s) under free radical polymerization conditions, preferably in the presence of a free radical generating initiator. The polymerization initiator may be water soluble or water soluble. Suitable free radical initiators are known from the state of the art. These include, for example, organic peroxides such as benzoyl peroxide, lauroyl peroxide, 2,5-dimethyl 2,5-di (2-ethylhexanoylperoxy) hexane and dicumyl peroxide; inorganic persulphates, such as ammonium, sodium or potassium persulphates; and azo initiators such as azobis (isobutyronitrile) (AiBN) and azobis (1-cyclohexanecarbonitrile); and redox pairs such as Fe2 + / H2O2, ROH / Ce4 + (where R corresponds to an organic group such as C1-6 alkyl or Cs-earil) and K2S20s / Fe2 +.

The polymerization temperature and other conditions of the polymerization stage are similar to those employed in processes known in the art. Generally, the polymerization temperature is in the range of 5 ° C to 120 ° C, preferably from 30 ° C to 90 ° C. The polymerization time is in the range of 120 minutes to 24 hours, preferably less than 600 minutes. The polymerization process may be conducted in a variety of known forms in the state of the art, including batch, semi-batch, and continuous processes, seeded or seedless processes, and operating conditions do not constitute a limitation to the watered process. Those skilled in the state of the art will appreciate that various modifications and substitutions can be made without disconfiguring the spirit and scope of the present invention. In a preferred description of the present invention, the post-consumption polystyrene hybrid aqueous dispersion / monomer is employed in seed processes. In a preferred description of this invention, the hybrid aqueous dispersion of post-consumption polystyrene droplets / monomer is initially polymerized according to known state-of-the-art processes and subsequently employed as seed in subsequent polymerization processes.

The resulting dispersion is useful in many applications. Products obtained in accordance with the present invention have similar applications to traditional lattices, such as preparation of decorative and protective coatings, films, contact adhesives, paints, glues, varnishes, civil construction adhesives, paper and cardboard coatings, among others. Surprisingly, the inventor It has been found that products obtained according to the process disclosed herein have properties superior to the characteristic properties of products obtained according to techniques known in the state of the art. Although the invention is not limited by any theory, it is believed that post-consumer polystyrene present in dispersed waste forms a reinforcing mesh with the polymerized monomers in the process. The hybrid structure formed by post-consumer polystyrene and polymerized monomers confers unexpected and improved final properties.

The following examples are provided by way of illustration of the invention, and do not limit the scope of the invention.

Example 1. Preparation of post-consumer polystyrene solution

21 grams of expanded polystyrene residue was dissolved at room temperature in 402 grams of styrene monomer. The monomer was poured into a becher, whereupon the polystyrene residue was then added. Instantly upon contact, the residue was dissolved, enabling the rapid addition of additional volumes of material. Dissolution was completed rapidly and with light agitation. The final solution had a viscosity of 9 mPa.s and did not show phase separation after laboratory rest for more than 2 months. The residue was collected from rejectitourbane and used without purification process, giving a yellowish coloration to the solution.

Example 2. Preparation of post-consumer polystyrene solution

Preparation of a post consumer monomer polystyrene mixture according to Example 1, wherein 44 grams of polystyrene residue was dissolved in 399 grams of styrene monomer. The final mixture had a viscosity of 27 mPa.s and showed no phase separation after laboratory rest for more than 2 months.

Example 3. Preparation of Post-Consumption Polystyrene Solution — Emonomer

Preparation of a post consumer monomer polystyrene mixture according to Example 1, wherein 56 grams of polystyrene residue was dissolved in 318 grams of styrene monomer. The final mixture had a viscosity of 80 mPa.s and showed no phase separation after laboratory rest for more than 2 months.Example 4. Preparation of post-consumption polystyrene solution and monomer

Preparation of a post consumer monomer polystyrene mixture according to Example 1, wherein 76 grams of polystyrene residue was dissolved in 305 grams of styrene monomer. The final mixture had a viscosity of 232 mPa.s and showed no phase separation after laboratory rest for more than 2 months.

Example 5. Preparation of post-consumer polystyrene solution

Preparation of a post consumer monomer polystyrene mixture according to Example 1, wherein 96 grams of polystyrene residue was dissolved in 289 grams of styrene monomer. The final mixture had a viscosity of 512 mPa.s and showed no phase separation after laboratory rest for more than 2 months.

Example 6. Preparation of post-consumer polystyrene solution in monomer

Preparation of a post-consumer monomer polystyrene mixture according to Example 1, wherein 118 grams of polystyrene residue was dissolved in 276 grams of styrene monomer. The final mixture had a viscosity of 1.3 Pa.s and showed no phase separation after resting in the laboratory for more than 2 months.

Example 7. Preparation of post-consumer polystyrene solution in monomer

Preparation of a post consumer monomer polystyrene mixture according to Example 1, wherein 26 grams of polystyrene residue was dissolved in 40 grams of styrene monomer. To this mixture was added 133.6 grams of butyl acrylate. The final mixture had a viscosity of 0.1 Pa.s and did not show phase separation after laboratory rest for more than 2 months.

Example 8. Preparation of aqueous dispersion of the polystyrene post-consumption and monomer mixture.

An aqueous solution containing 275 grams of deionized water, 4 grams of sodium lauryl sulfate and 0.3 grams of NaHCCb was mixed with the mixture prepared in Example 7 employing magnetic stirring. The aqueous dispersion was sonicated for 10 minutes at power 9, employing the Transon Sonifier 450W sonicator. The hybrid post-consumption polystyrene / monomer droplet size was measured by the light scattering technique using the Malvem Zetasizer 1000 equipment. A value of 208 nm was found.

Example 9. Polymerization of Post Consumption / Monomer Hybrid Mini Emulsion

The dispersion prepared according to Example 8 was fed to a reactor. The system was heated to 70 ° C. After temperature stabilization for 15 minutes, 25 grams of an aqueous ammonium persulfate solution was added to the reactor. The polymerization was conducted thermally and in batch for 120 minutes. A clot-free latex was obtained, and after resting in the laboratory for more than 6 months, no separation was observed. The solids content was evaluated by gravimetry, obtaining 40% w / w. Latex viscosity was measured with a Brookfield type viscometer, resulting in 36 mPa.s. The z-mean particle size was measured via light scattering using the Malvern Zetasizer 1000 HS equipment with a 180 nm result. The glass transition temperature was evaluated by the DSC technique using the TA Instruments DSC Q100 equipment. A clear transition at -32 ° C, and a smooth transition in the region of 109 ° C was observed. Example 10. Preparation of post-consumer polystyrene solution

Preparation of a post consumer monomer polystyrene mixture according to Example 1, wherein 142 grams of polystyrene residue was dissolved in 802 grams of styrene monomer and 42 grams of acrylic acid. The residue was dissolved immediately after contact with the monomer solution, resulting in a clear solution with no phase separations after long aging in the laboratory.

Example 11. Preparation of aqueous dispersion of the polystyrene post-consumption and monomer mixture.

An aqueous solution containing 1332 grams of deionized water, 6.3 grams of a 50% w / w aqueous NaOH solution, 1.6 grams of Aerosol MA-80 (Cytec) and 11 grams of Rhodacal DSB (Rhodia) was mixed together with The mixture prepared in Example 10 for 15 minutes employing mechanical stirring. The dispersion was then transferred to a high pressure homogenizer (Artepeças APL 500, Brazil) and subjected to a homogenization cycle at 20 MPa. The final hybrid droplet size, analyzed by the light scattering technique with the MalvernZetasizer 1000 HS, was 360 nm.

Example 12. Polymerization of Post Consumption / Monomer Hybrid Mini Emulsion

700 grams of mini emulsion prepared according to Example 11a was added to a polymerization reactor. The system was heated to 80 ° C and the temperature kept constant for 15 minutes. Then, an aqueous solution composed of 35 grams of deionized water and 1.5 grams of ammonium sulfate was added to the reactor, allowing the system to react in a quench for 60 minutes. After completion of the initial step, 1634 grams of the mini-emulsion prepared according to Example 11 was added concurrently with an aqueous solution composed of 110 grams of deionized water and 4.2 grams of ammonium persulfate over a 180 minute period. At the end of the additions, the system was allowed to cool for 60 minutes.

A solids-free clot-free latex, measured by the gravimetry technique, of 37% w / w was obtained. The average particle size obtained was 362 nm.

Example 13. Seed emulsion polymerization employing post-consumer polystyrene / polymer hybrid particles

To the initial charge containing 1200 grams of the latexobtide according to Example 12, 430 grams of deionized water, 3.2 grams of Rhodacal DSB (Rhodia) was added. The temperature of the reaction medium was adjusted to 90 ° C. Then, an aqueous solution composed of 50 grams of deionized water and 6 grams of deammonium persulfate was added to the reactor, keeping the system isothermal for 60 minutes. A mixture containing 750 grams of styrene, 13.7 grams of tert-dodecyl mercaptan, 52 grams of acrylic acid and 458 grams of butadiene was prepared in a pressurized vessel. This mixture was added to the reactor at constant flow for a period of 270 minutes in parallel with the addition of an aqueous solution composed of 220 grams of deionized water, 6 grams of deammonium persulfate and 15 grams of Rhodacal DSB (Rhodia). The system was allowed to cool to room temperature 60 minutes after completion of the additions. A solid-free clot-free latex, measured by the degravimetry technique, was obtained at 50.7% w / w. The average particle size obtained was 254 nm.

Example 14. Seed emulsion polymerization employing post-consumer polystyrene / polymer hybrid particles. Added to the initial charge containing 533 grams of the latex obtained according to Example 12, 366 grams of deionized water, 5.0 grams of Rhodacal DSB (Rhodia). The temperature of the reaction medium was adjusted to 90 ° C. Then, an aqueous solution consisting of 50 grams of deionized water and 6 grams of ammonium persulphate was added to the reactor, maintaining the system isothermal for 60 minutes. A mixture containing 767 grams of styrene, 19 grams of deterc-dodecyl mercaptan, 66 grams of acrylic acid and 714 grams of debutadiene was prepared in a vasopressurized. This mixture was added to the reactor at a constant flow rate for a period of 270 minutes in parallel with the addition of an aqueous solution composed of 625 grams of deionized water, 8 grams of deammonium persulfate and 18.5 grams of Rhodacal DSB (Rhodia). The system was allowed to cool to room temperature 60 minutes after completion of the additions. A solid-free clot-free latex, measured by the degravimetry technique, was obtained at 51.5% w / w. The average particle size obtained was 203 nm.

Example 15. State-of-the-art seed emulsion polymerization

Preparation of an aqueous polymeric dispersion according to Example 14, wherein the seed employed in the polymerization process was obtained by batch emulsion polymerization consisting of 350 grams of styrene, 15 grams of acrylic acid, 556 grams of water-based and 74 grams of lauryl. sodium sulfate. A decoagulum-free latex with solids content, measured by the gravimetry technique, of 50.5% w / w was obtained. The average particle size obtained was 190 nm.

Example 16. Application on Paper Coating

The performance of latex produced according to the processor disclosed in the present invention, as illustrated in Example 14, was compared with the performance of a latex obtained according to the state of the art. The formulation used in the preparation of the paper coating formulation is detailed below:

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The coating formulations had similar physicochemical properties. The solids content measured by gravimetry, Brookfield viscosity and pH measured for the top-coat formulation with the slopes obtained according to Examples 14 and 15 had the following values: 59.9%, 1000 mPa.s, 8.8 and 59 , 5%, 980 mPa.s, 8.9, respectively. Gravity measured solids content, Brookfield viscosity and pH measured for the latex pre-coat formulation according to Examples 14 and 15 had the following values: 35.1%, 80 mPa.s, 9.1 and 35, 2%, 86 mPa.s, 9.1, respectively. A standard paper base weighing 70 grams per square meter was used. The properties of the coating were analyzed using standard IGT equipment and materials, following TAPPI procedures. The observed dry pick was 1.16 and 1.3 m / s for the formulation coated paper containing the latex prepared according to Example 14 and 15, respectively.

Example 17. Preparation of latex via mini-emulsion polymerization according to state of the art procedure 4 grams of hexadecane was added to a demonomer solution consisting of 151 grams of butyl acrylate and 45 grams of styrene. An aqueous solution composed of 275 grams of deionized water, 4 grams of sodium lauryl sulfate and 0.3 grams of NaHCCb was mixed with the previously prepared organic solution with the aid of a magnetic stirrer. The resulting aqueous dispersion was sonicated for 10 minutes at power 9. The average droplet size was evaluated by the light scattering technique using the Malvern Zetasizer 1000 equipment, yielding 190 nm. The resulting dispersion of the sonication process was added to a reactor. The system was heated to 70 ° C. After temperature stabilization for 15 minutes, 25 grams of a 4% w / w aqueous solution of ammonium persulfate was added to the reactor. The polymerization was isothermally conducted and in batch for 120 minutes.

A clot-free latex was obtained. The solids content was evaluated by gravimetry technique and the obtained result was 39%.

Example 18. Comparative Evaluation of Mechanical Properties

The latices obtained according to procedures 9 and 16 were thickened using traditionally widely known acrylic thickeners in the market. The thickened latex was then poured into a mold to obtain specimens following standardized procedures in the literature. —Mechanical properties were evaluated using the EMIC DL2000 tensiometer. The modulus corresponding to 18 times the original body length The test sample was measured at 1.9 kgf / cm2 and 2.4 kgf / cm2 for the samples obtained with the synthesized latex according to the procedure described in Examples 9 and 16, respectively.

Claims (16)

1.- Process for the production of reinforced hybrid polymeric materials, characterized by: a. Dissolution of post-consumer polystyrene or expanded polystyrene in a suitable unsaturated ethylenic monomer or a mixture of unsaturated ethylenic monomers.b. Formation of a mixture of (a) with another unsaturated ethylenic demonomer solution or monomers.c. Dispersion of the mixture prepared in (b) in an aqueous solution containing suitable emulsifiers. Processing of the aqueous dispersion prepared in (c) under conditions suitable for the formation of sub-micrometric hybrid polymer-monomer composition.e. Processing the dispersion formed in (d) under conditions suitable for polymerization of the monomers, forming a particle distribution containing the polymer-polymer hybrid material with an average size preferably less than 1000 nm. 2. A process according to claim 1, characterized in that it is post-consumer polystyrene composed of polystyrene and / or expanded polystyrene. 3. A process according to claim 2, characterized in that it is the post-consumer polystyrene obtained from any tailings. 4. A process according to claim 3, characterized in that it is the post-consumption polystyrene used as obtained from the tailings, without the prior separation of its components and additives. 5. A process according to claim 1 wherein the percentage of post-consumption polystyrene corresponds to more than 0.1% by weight on the total weight of the polymeric aqueous dispersion, preferably above 1% and even more preferably above 10%. %. 6. A process according to claim 1 wherein the mixture of post-consumer polystyrene and unsaturated ethylene monomer (s) is present, viscosity of less than 2 Pa.s measured at room temperature. 7. A process according to claim 1 wherein the mixture is post-consumer polystyrene and unsaturated ethylene monomer (s) mixed with an aqueous phase containing surfactants. 8. A process as claimed in claim 7 wherein the initial aqueous dispersion is subjected to high energy homogenization equipment producing hybrid droplets of less than 700 nm in size. 9. A process according to claim 1 wherein the aqueous dispersion of hybrid droplets is polymerized in batch, semi-batch or continuous processes to obtain reinforced hybrid polymer particles. 10. A process according to claim 9, characterized in that the polymeric aqueous dispersion is further employed in dispersed medium polymerization processes. 11. Polymeric particle dispersion characterized in that they are prepared according to the process of claim 1. 12. Polymeric particle dispersion characterized in that they are prepared according to claim 9. 13. Polymeric particle dispersion characterized in that they are prepared according to claim 10. 14. A solid film or material characterized by coagulation or drying of the resulting dispersion according to claim 1. 15.- Solid film or material characterized by coagulation or drying of the resulting dispersion according to claim 9. 16.- A film or solid material characterized by coagulation or drying of the resulting dispersion according to claim 10.