CN105440326A - Ageing-resistant hydrophobically modified starch PVC composite degradable plastic and preparation method thereof - Google Patents

Abstract

The invention discloses an ageing-resistant hydrophobically modified starch PVC composite degradable plastic. The plastic is prepared from, by weight, 0.7-0.9 parts of tetrabutyl titanate, 2.3-2.6 parts of triethanolamine, 2.3-2.5 parts of tall oil, 1.6-1.8 parts of cerium butanetetracarboxylate, 3.4-3.7 parts of methyltin mercaptide, 0.2-0.3 parts of hexadecyl guanidinium salt, 0.3-0.4 parts of dicumyl peroxide, 3-3.4 parts of triallyl isocyanurate, 333-341 parts of starch, 300-350 parts of PVC, 3.6-3.8 parts of aluminum isopropoxide, 15-17 parts of isopropanol, 120-125 parts of water, 12-13 parts of nitric acid and 60-65 parts of hydrogen peroxide. Triethanolamine, tall oil, cerium butanetetracarboxylate and methyltin mercaptide are used in the invention, so the heat resistance, the flexibility and the water resistance of the plastic are improved, and performances of various starch-based plastic products are met.

Description

A kind of ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics and preparation method thereof

Technical field

The present invention relates to degradative plastics technical field, particularly relate to a kind of ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics and preparation method thereof.

Background technology

Starch is compound of polysaccharide, belongs to natural macromolecular material, and source is very extensive, and starch has wide application in fields such as weaving, papermaking, petroleum industries.Since the sixties in 20th century, along with the minimizing day by day of earth petroleum resources, pollute because of plastic white and cause increasing the weight of gradually of environmental degradation, bio-degradable plastics enjoys the favor of research both at home and abroad.Because starch has good biodegradability, the biomass research as biodegradable plastic achieves certain achievement.But native starch polyhydroxy structure inherently makes its polarity comparatively strong, cause starch and synthetic resins mutual compatibility that is nonpolar or low-pole poor, limit its application in biodegradable plastic.Address this problem at present and mainly take to carry out hydrophobization process to starch.The method of modification mainly contains the methods such as physically modified, chemical modification, coupling modifier.Wherein, physically modified: adopt sonic oscillation can effectively make starch granules miniaturization, specific surface area increases, but hydrophobic effect is not good; Chemical modification: usually use various chemical reagent substituted hydroxy, substitution value is low, hydrophobic effect is not remarkable, and the aftertreatment of cost height is complicated.Coupling modifier: technique is simple, pollution-free, hydrophobic effect is remarkable, but starch particle diameter after process is large and uneven, affects the consistency between itself and synthetic resins.Physics is combined with coupling modifier organic phase by this problem, establishes a kind of composite modifying method new technology, the coupling of many methods, has complementary advantages, obtains high hydrophobicity starch.High hydrophobicity starch is added in polyvinyl chloride (PVC) and polyvinyl alcohol (PVA) respectively, prepared biodegradable PVC plastic and PVA film.Structural characterization and performance test have been carried out to high hydrophobicity starch, biodegradable PVC plastic and PVA film.The preparation and property test of high hydrophobicity starch: first W-Gum is carried out ultrasonic refining, with the hydrophobic performance of treated starch for index, examine modification time, modification temperature, stirring velocity, coupling agent consumption and hydrophobizing agent consumption to the impact of treated starch hydrophobic performance.Determine best modified condition, contact angle test display: the contact angle of modified starch obviously increases (141 ~ 143 °), wherein, coupling agent phthalandione four butyl esters/hydrophobizing agent stearic acid is compared with the hydrophobically modified better effects if of coupling agent silane/hydrophobizing agent peanut oil to starch.Infrared analysis result shows: after sonic oscillation, in starch, the stretching vibration peak of O-H becomes 3436cm-1 from 3423cm-1, illustrates that sonic oscillation can make hydrogen bond rupture between O-H and dissociate.After hydrophobically modified, in starch, the stretching vibration peak of O-H reduces to 3411cm-1 again, and this is the result of starch surface hydroxyl and coupling agent and hydrophobizing agent effect.Scanning electron microscope analysis shows: after sonic oscillation, starch particle diameter significantly diminishes, and is uniformly dispersed, and agglomeration reduces, and the uniform mottled modified material of surface attachment, shows that properties-correcting agent is on the starch particles coated.Starch base PVC plastic preparation and property test: will make by oneself respectively treated starch in varing proportions (20%, 40%, 60%) join in the PVC raw material of same formula, degradative plastics sheet material is prepared after blended, stretch-proof experimental result shows: level of modified starch 20 ~ 60%, tensile strength 25.49MPa ~ 17.99MPa, can meet the performance of various starch plastics product.The preparation and property test of starch base PVA film: first by PVA and water heating for dissolving completely, then once add the starch of coupling agent, softening agent and hydrophobically modified, be uniformly mixed, discontinuous degassing, casting film.With rate of descent and tensile strength for main performance index, be reference index with transmittance, consider selection optimum preparating condition.Biological degradation rate is tested: employing soil buries method and the biodegradability of cultivation liquid method to starch base PVC plastic sheet material and starch base PVA film has carried out preliminary test, and experimental result shows: starch base PVC plastic and PVA film all show good biodegradability.Wherein, starch base PVC plastic is after burying experiment through 4 months soil, and biological degradation rate reaches 61.8%, adopt cultivation liquid method after 40 days, biological degradation rate can reach 54%, and after starch base PVA film adopts cultivation liquid method to degrade 40 days, biological degradation rate can reach 68%.This research establishes a kind of novel method preparing high hydrophobicity starch.The method technique is simple, environmental protection, and cost is low, is expected to suitability for industrialized production, and popularizing application prospect is had an optimistic view of.Made high hydrophobicity starch can respectively as the good biological matter of PVC and PVA plastics, and the starch base PVC plastic prepared with it and PVA plastics have good physicals and biodegradability.

" the composite hydrophobic modification of starch and the applied research in biodegradable plastic thereof " literary composition gives starch composite modified method, obtains good hydrophobicity starch.But the method modification of starch in literary composition, in starch molecule glucose unit C6 atom on primary hydroxyl and be easily hydrolyzed, hydrophobic performance should be not.The Sumstar 190 that simple hydrogen peroxide oxidation obtains is along with the increase of aldehyde, ketone content in oxidising process, and the hydrophobic performance of thermoplasticity Sumstar 190 is significantly improved, and the mechanical property of material significantly improves.But in oxidising process, the molecular weight of starch can sharply decline, and due to the poor heat stability of aldehyde radical, the resistance toheat of Sumstar 190 thus can be made to decrease.Therefore the imperfect problem of the water tolerance that current treated starch also exists, thermotolerance, mechanical property, requires further improvement.

Summary of the invention

The object of the invention is exactly the defect in order to make up prior art, provides a kind of ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics and preparation method thereof.

The present invention is achieved by the following technical solutions:

A kind of ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics, is made up of the raw material of following weight part: tetrabutyl titanate 0.7-0.9, trolamine 2.3-2.6, tall oil 2.3-2.5, butane tetracid cerium 1.6-1.8, thiol methyl tin 3.4-3.7, hexadecyl guanidinesalt 0.2-0.3, dicumyl peroxide 0.3-0.4, cyanacrylate 3-3.4, starch 333-341, PVC300-350, aluminum isopropylate 3.6-3.8, Virahol 15-17, water 120-125, nitric acid 12-13, hydrogen peroxide 60-65.

The preparation method of described ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics, comprises the following steps:

(1) by aluminum isopropylate, Virahol mixing, be heated to 78-80 DEG C, nitric acid be added to the water and stir 60-70min, then add tetrabutyl titanate, stir, leave standstill 3-4 hour, obtain mixture;

(2) starch is mixed with trolamine, tall oil, butane tetracid cerium, grinding evenly, spray into the mixture that (1) step obtains while stirring, after stirring, add hydrogen peroxide, mix, be heated to 78-80 DEG C, stirring reaction 30-40 minute, regulates pH to be neutral, obtains treated starch;

(3) treated starch is mixed in high-speed mixer with other remaining components mix 4-5 minute, then send into parallel double-screw extruder, extruding pelletization at 140-145 DEG C;

(4) pellet (3) step obtained is sent in mill and is hacked at 140-145 DEG C, then sends in extrusion press, at 170-180 DEG C of lower sheeting process 3-4 minute, at room temperature crosslinked 1-2 hour, to obtain final product.

Advantage of the present invention is: the present invention is by using aluminum isopropylate, tetrabutyl titanate, nano particle is defined on starch surface, and size distribution is extremely even, be combined firmly with starch granules, after anti-oxidation, molecular weight gathers decline, greatly improve the water tolerance of starch, ageing resistance, thermotolerance and cohesiveness, strengthen with the bonding force of plastics, improve the mechanical property of composite plastic; By using trolamine, tall oil, butane tetracid cerium, thiol methyl tin, improve the thermotolerance of plastics, snappiness, water tolerance, the performance of various starch plastics product can be met.

Embodiment

A kind of ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics, is made up of the raw material of following weight part (kilogram): tetrabutyl titanate 0.7, trolamine 2.3, tall oil 2.3, butane tetracid cerium 1.6, thiol methyl tin 3.4, hexadecyl guanidinesalt 0.2, dicumyl peroxide 0.3, cyanacrylate 3, starch 333, PVC300, aluminum isopropylate 3.6, Virahol 15, water 120, nitric acid 12, hydrogen peroxide 60.

The preparation method of described ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics, comprises the following steps:

(1) by aluminum isopropylate, Virahol mixing, be heated to 78 DEG C, nitric acid be added to the water and stir 60min, then add tetrabutyl titanate, stir, leave standstill 3 hours, obtain mixture;

(2) mixed with trolamine, tall oil, butane tetracid cerium by starch, grinding evenly, sprays into the mixture that (1) step obtains, after stirring while stirring, add hydrogen peroxide, mix, be heated to 78 DEG C, stirring reaction 30 minutes, regulates pH to be neutral, obtains treated starch;

(3) treated starch is mixed in high-speed mixer with other remaining components mix 4 minutes, then send into parallel double-screw extruder, extruding pelletization at 140 DEG C;

(4) pellet (3) step obtained is sent in mill and is hacked at 140 DEG C, then sends in extrusion press, 170 DEG C of lower sheeting process 3 minutes, at room temperature crosslinked 1 hour, to obtain final product.

The tensile strength of this embodiment composite plastic is 35.8MPa after tested, and elongation at break is 320%, 200 DEG C of heat-stable times is 280min, and impact embrittlement temperature and be-35 DEG C, hot unit elongation is 145%.

Claims (2)

1. an ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics, is characterized in that being made up of the raw material of following weight part: tetrabutyl titanate 0.7-0.9, trolamine 2.3-2.6, tall oil 2.3-2.5, butane tetracid cerium 1.6-1.8, thiol methyl tin 3.4-3.7, hexadecyl guanidinesalt 0.2-0.3, dicumyl peroxide 0.3-0.4, cyanacrylate 3-3.4, starch 333-341, PVC300-350, aluminum isopropylate 3.6-3.8, Virahol 15-17, water 120-125, nitric acid 12-13, hydrogen peroxide 60-65.

2. the preparation method of ageing-resistant Hydrophobic Modified Starch PVC composite degradable plastics according to claim 1, is characterized in that comprising the following steps:

(1) by aluminum isopropylate, Virahol mixing, be heated to 78-80 DEG C, nitric acid be added to the water and stir 60-70min, then add tetrabutyl titanate, stir, leave standstill 3-4 hour, obtain mixture;

(2) starch is mixed with trolamine, tall oil, butane tetracid cerium, grinding evenly, spray into the mixture that (1) step obtains while stirring, after stirring, add hydrogen peroxide, mix, be heated to 78-80 DEG C, stirring reaction 30-40 minute, regulates pH to be neutral, obtains treated starch;

(3) treated starch is mixed in high-speed mixer with other remaining components mix 4-5 minute, then send into parallel double-screw extruder, extruding pelletization at 140-145 DEG C;

(4) pellet (3) step obtained is sent in mill and is hacked at 140-145 DEG C, then sends in extrusion press, at 170-180 DEG C of lower sheeting process 3-4 minute, at room temperature crosslinked 1-2 hour, to obtain final product.