CN1637053A - Completely biodegradable starch-base plastics and plastomer material and their prepn process - Google Patents

Abstract

The present invention is completely biodegradable starch-base plastics and rubber material and their preparation process. The completely biodegradable starch is added with high efficiency organic plasticizer and heat stabilizer and the mixture is processed through extrusion, molding, injection and spinning to form completely biodegradable starch-base plastics and rubber material. The starch-base plastics and rubber material may be thermoplastic processed, has excellent mechanical performance, no ageing and practical production value, and is environment friendly without environmental pollution.

Description

The full starch plastics of complete biodegradable, elastomer material and preparation method thereof

] technical field

The invention belongs to full starch plastics, elastomer material of complete biodegradable and preparation method thereof.

Background technology

For reducing the white pollution that macromolecule product causes, all be devoted to exploitation both at home and abroad and both had advantageous property, simultaneously degradable again plastics of new generation, elastomer product.Wherein a class is to utilize general-purpose plastics such as polyethylene, polypropylene etc. as matrix, again the biodegradable plastic that is mixed and made into mutually under certain condition with degradable macromolecular materials such as starch.Existing many patents of this series products such as CN1049671, patent 00105580.1 etc.But this series products can only the part degraded, as disposable food packing film or plastic film for agricultural use, its resistates will destroy Soil structure, influences plant growth.Another kind of is the aliphatic poly ester material, but this class material is because problems such as high-crystallinity that high taxis itself causes and secondary crystal make that their mechanical property is very poor, and process window is very narrow; On the other hand, the price of aliphatic polyester is several times of common high molecular materials, is difficult to realize suitability for industrialized production before its massive decrease of prices.Also having a class is to be thermoplastics type's material of base material with natural polysaecharides macromole such as starch, though as using plastifying starch plastics degradables such as glycerine, ethylene glycol, sorbyl alcohol, wearing out of material is very obvious, and range of application is restricted.

In numerous biodegradable polymers, polysaccharide compound, as starch (starch) and derivative thereof etc., demonstrate its excellent biocompatibility, biological degradability, extraordinary wetting ability, wide application field, significant environmental benefit and social benefit.Compare with traditional plastics, polysaccharide compound has been broken away from the dependence to petroleum resources, in petroleum day by day nervous today, and can be owing to oil crisis causes raw-material in short supply.And after they were decomposed, its final product was water and carbonic acid gas, therefore can not produce harm to environment, can also be used for making compost, and as fertilizer sources or soil improvement agent go back to nature.And the price of starch is very cheap, has absolute price to strive advantage unexpectedly with respect to general petroleum base macromolecular material, and they are a kind of reproducible resources simultaneously, and annual a large amount of animals and plants are by the synthetic a large amount of starch of biological methods such as photosynthesis.Finding out terms of settlement if can seek out solution at the deficiency as the material aspect of starch, all is the immeasurable thing of social morality for the tellurian mankind and other biology and all biological offsprings so.

Have numerous hydroxyls on the starch polymer, wetting ability is very strong, but they are water insoluble, and this is because the cause by hydrogen bonded between the hydroxyl.Because intramolecularly is numerous from hydrogen bond, make pure starch not have second-order transition temperature and fusing point, even add the heat decomposition temperature of thermic starch, starch still can't carry out thermoplasticity processing.In addition, though can access thermoplastic starch-based material after adding the softening agent of other kinds, the general snappiness that the ordering rearrangement of starch molecule and crystalline effect make its material present when just having processed in this material in the one day time to about a week becomes crisp, rigid, can't obtain the starch-base biodegradation material of actual application value to such an extent as to mechanical property significantly descends.

Summary of the invention

The purpose of this invention is to provide full starch plastics, elastomer material of a kind of complete biodegradable and preparation method thereof

The method for toughening of the present invention by efficient, persistent softening agent being provided and being convenient to process uses the starting material that extensively are easy to get, and prepares starch plastics, elastomer material with excellent mechanical properties.

Shortcomings such as low and product is easily aging at the mechanical property of this biodegradable polymer poor processability of starch, product, provide two classes efficient, persistent softening agent, wherein a class softening agent is by the active sulfuryl on the molecule, the hydroxyl generation intensive hydrogen bond association on sulfoxide group and the starch polymer; Another kind of is combination and hydroxyl generation intensive hydrogen bond on the starch polymer and the ionic linkage association that amide group and lithium ion form, make starting material can in the temperature range of normal temperature to 170 ℃, finish processing smoothly, and then overcome the shortcoming that to carry out thermoplasticity processing of material from can not melt-processed becoming.Such softening agent has suppressed the recrystallization of starch fully, and has prevented from significantly in storage process the significantly improving of mechanical property of starch particularly to increase its toughness because molecular chain catabiosis that short range orderization produces makes.Be lower than the feature that 30% o'clock bill of material reveals plastics for plasticizer loading; Be higher than 30% o'clock bill of material for plasticizer loading and reveal elastomeric feature.Such softening agent can make the elongation at break of material significantly increase, and reaches original more than 50 times.On this basis, cooperate and add extender plasticizer, thermo-stabilizer, and in conjunction with complete processing, can further reduce the processing temperature of material, improve the flexible of material and shorten process period greatly and promptly help overcoming the thermal destruction of material in the high temperature process process, promptly save the energy, help again saving time.Prepare the biodegradable full starch plastics, the elastomeric material that have good mechanical properties, do not have catabiosis and have actual production to be worth.

The selected polysaccharide compound of the present invention is:

The various types of starch and the modified starch of one or more complete biodegradables.Softening agent is:

1) R ₁-SO-R ₂Or R ₁-SO ₂-R ₂, R wherein ₁And R ₂Be alkyl, cycloalkyl, phenyl, benzyl, carboxyl, amino or the hydroxyl of H, different lengths, wherein R ₁And R ₂Can be the same or different, but cannot be H simultaneously;

2) N,N-dimethylacetamide (DMAC)/lithium chloride (LiCl) or N, dinethylformamide (DMF)/lithium chloride (LiCl)

Extender plasticizer is:

Water, glycerine, ethylene glycol, polyoxyethylene glycol, dioctyl phthalate (DOP) (DOP), diethyl phthalate (DEP), dimixo-octyl phthalate (DIOP), Octyl adipate (DOA) or tributyl citrate.

Thermo-stabilizer is:

Four [3-(3 ', 5 '-di-t-butyl-4 '-hydroxy phenyl) propionic acid] wherein one or both of pentaerythritol ester (antioxidant 1010), three (2, the 4-di-tert-butyl-phenyl) phosphorous acid esters (oxidation inhibitor 168), two (octadecyl) pentaerythritol diphosphites (oxidation inhibitor 618) or MALEIC ANHYDRIDE.

The biodegradable full starch plastics of fully biodegradable, its weight of elastomer material % are:

One or more various types of starch and modified starch 90-50

Softening agent 10-50

Extender plasticizer 0-20

Thermo-stabilizer 0.5-9

The melt blending process: starting material just mix in homogenizer in proportion in advance, and mixing in Banbury mixer then, melting temperature is 50-160 ℃, and mixing time is 5-20min, Banbury mixer rotating speed 20-50rpm/min; Its twin screw is extruded processing conditions: temperature in 50-120 ℃, the mixing section temperature is 70-150 ℃, and the fluxing zone temperature is 85-165 ℃, and extrusion temperature is 65-130 ℃, and screw speed is 80-120rpm/min.The products therefrom tensile strength is: 0.92-39.0MPa, elongation at break is: 4.1%-293%.

The mechanical property of product characterizes: the material of blend is through the vulcanizing press compressing tablet, and the stability of separated deposit 1 month and 1 year contrast material at room temperature is cut into batten with the standard cutting knife more again.All battens are on tester for elongation (Instron model 1211), and the speed with 10mm/minute or 50mm/minute under the room temperature stretches.

The aging resistance of product characterizes and selects x-ray diffractometer (Philips PW1700 type x-ray diffractometer) for use, and scanning angle is the 5-45 degree.

Embodiment

Embodiment 1: press column weight amount % and take by weighing each component:

Conventional corn starch (amylose starch 27%) 98.0

Antioxidant 1010 0.5

MALEIC ANHYDRIDE 1.5

Mix with Banbury mixer, mixing temperature 100-160 ℃, mixing time 5-15min, Banbury mixer rotating speed 20-50rpm/min.The gained material is so because so starch can't carry out the melt-processed starch granules to it in the course of processing can not form external phase and can't carry out mechanical property table test.

Embodiment 2: press column weight amount % and take by weighing each component:

Conventional corn starch (amylose starch 27%) 88.2

Dimethyl sulfoxide (DMSO) 9.8

Oxidation inhibitor 618 0.1

MALEIC ANHYDRIDE 1.5

Mix 80 ℃ of mixing temperatures, mixing time 15min, Banbury mixer rotating speed 30rpm/min with Banbury mixer.The gained material, the mechanical property characterization result is as follows: the yield strength after month is 28.5MPa, and tensile strength is 27.6MPa, and elongation at break is 4.1%; Yield strength after 1 year is 30.2MPa, and tensile strength is 29.3MPa, and elongation at break is 4.0%.As seen comparative example 1-2 adds behind the toughner starch can finish processing smoothly from can not melt-processed becoming on universal machine.

Embodiment 3: press column weight amount % and take by weighing each component:

Viscous maize starch (amylose starch＜1%) 68.6

Dibenzyl sulfoxide 26.5

Water 2.9

Oxidation inhibitor 168 0.1

MALEIC ANHYDRIDE 1.5

Extruding processing conditions with twin screw is: 120 ℃ of temperature ins, mixing section temperature are 150 ℃, and the fluxing zone temperature is 165 ℃, and extrusion temperature is 130 ℃, and screw speed is 120rpm/min.The gained material, the mechanical property characterization result is as follows: the yield strength after month disappears, and tensile strength is 39.0MPa, and elongation at break is 35%; Yield strength after 1 year disappears, and tensile strength is 36.7MPa, and elongation at break is 39%.

Embodiment 4 presses column weight amount % and takes by weighing each component:

High-effective cationic starch (substitution value 0.01) 63.7

DMF/LiCL 14.3

Glycerine 20.0

Oxidation inhibitor 168 0.1

MALEIC ANHYDRIDE 1.5

Prior to just mixing in the homogenizer, mixing 10 minutes of 140 ℃ of left and right sides in Banbury mixer again, rotating speed is 50rpm/min.The gained material, the mechanical property characterization result is as follows: yield-point after one month disappears and the platform of rubbery state occurs on stress strain curve, and tensile strength is 1.83MPa, and elongation at break is 245%; Yield strength after 1 year disappears, and tensile strength is 1.75MPa, and elongation at break is 257%.

Embodiment 5 presses column weight amount % and takes by weighing each component:

Green starch 58.8

DMAC/LiCL 35.2

DOA 4.0

Oxidation inhibitor 168 0.1

MALEIC ANHYDRIDE 1.5

Prior to just mixing in the homogenizer, mixing 10 minutes of 150 ℃ of left and right sides in Banbury mixer again, rotating speed is 25rpm/min.The gained material, the mechanical property characterization result is as follows: yield-point after one month disappears and the platform of rubbery state occurs on stress strain curve, and tensile strength is 1.4MPa, and elongation at break is 175%; Yield strength after 1 year disappears, and tensile strength is 1.35MPa, and elongation at break is 167%.

Embodiment 6 presses column weight amount % and takes by weighing each component:

Conventional corn starch (amylose starch 27%) 49.0

Dimethyl sulfoxide (DMSO) 45.0

DIOP 2.5

Ethylene glycol 2.5

Oxidation inhibitor 168 0.1

Prior to just mixing in the homogenizer, mixing 20 minutes of 50 ℃ of left and right sides in Banbury mixer again, rotating speed is 25 rev/mins.The gained material, the mechanical property characterization result is as follows: yield-point after one month disappears and the platform of rubbery state occurs on stress strain curve, and tensile strength is 1.01MPa, and elongation at break is 305%; Yield strength after 1 year disappears, and tensile strength is 0.92MPa, and elongation at break is 293%.

Comparative example 2-6, in starch, add an amount of softening agent as can be seen, allow starch carry out material processed and make the elongation at break of starch increase, be attended by the decline of modulus and intensity simultaneously along with the increase of plasticizer loading from can't the thermoplastic material processed becoming available general plastics machinery. Reveal the peculiar mechanical property of rubber when the content of softening agent is increased to 30% bill of material when above, this moment, the aging recrystallization and the local ordering phenomenon of starch disappeared.

Embodiment 7 presses column weight amount % and takes by weighing each component:

Anionic starch (substitution value 0.005) 75.0

Dimethyl sulfone 22.0

DOP 3.0

Antioxidant 1010 0.1

Prior to just mixing in the homogenizer, mixing 20 minutes of 130 ℃ of left and right sides in Banbury mixer again, rotating speed is 20rpm/min.The gained material, the mechanical property characterization result is as follows: the yield strength after month is 34.5MPa, and tensile strength is 31.6MPa, and elongation at break is 12.1%. Yield strength after 1 year is 32.8MPa, and tensile strength is 27.5MPa, and elongation at break is 14.9%.

Embodiment 8: press column weight amount % and take by weighing each component:

Anionic starch (substitution value 0.005) 89.9

Tetramethylene sulfone 7.0

DEP 3.0

Antioxidant 1010 0.1

Prior to just mixing in the homogenizer, mixing 20 minutes of 130 ℃ of left and right sides in Banbury mixer again, rotating speed is 25rpm/min.The gained material, the mechanical property characterization result is as follows: the yield strength after month is 27.8MPa, and tensile strength is 26.3MPa, and elongation at break is 8.1%; Yield strength after 1 year is 33.9MPa, and tensile strength is 29.5MPa, and elongation at break is 10.3%.

Embodiment 9: press column weight amount % and take by weighing each component:

Yam starch 48.8

Viscous maize starch 10.0

Dimethyl sulfoxide (DMSO) 35.2

Water 4.0

Oxidation inhibitor 168 0.1

MALEIC ANHYDRIDE 1.5

Extruding processing conditions with twin screw is: 50 ℃ of temperature ins, mixing section temperature are 70 ℃, and the fluxing zone temperature is 85 ℃, and extrusion temperature is 65 ℃, and screw speed is 80rpm/min.The gained material, the mechanical property characterization result is as follows: yield-point after one month disappears and the platform of rubbery state occurs on stress strain curve, and tensile strength is 1.01MPa, and elongation at break is 105%; Yield-point after 1 year disappears and the platform of rubbery state occurs on stress strain curve, and tensile strength is 1.24MPa, and elongation at break is 123%.

Claims (1)

1, a kind of plastics of polyose of complete biodegradable, elastomer material is characterized in that selected polysaccharide compound is: the various types of starch and the modified starch of one or more complete biodegradables;

Softening agent is:

1) R ₁-SO-R ₂Or R ₁-SO ₂-R ₂, R wherein ₁And R ₂Be alkyl, cycloalkyl, phenyl, benzyl, carboxyl, amino or the hydroxyl of H, different lengths, wherein R ₁And R ₂Can be the same or different, but cannot be H simultaneously;

2) N,N-dimethylacetamide (DMAC)/lithium chloride (LiCl) or N, dinethylformamide (DMF)/lithium chloride (LiCl);

Extender plasticizer is:

Water, glycerine, ethylene glycol, polyoxyethylene glycol, dioctyl phthalate (DOP) (DOP), diethyl phthalate (DEP), dimixo-octyl phthalate (DIOP), Octyl adipate (DOA) or tributyl citrate;

Thermo-stabilizer is:

Four [3-(3 ', 5 '-di-t-butyl-4 '-hydroxy phenyl) propionic acid] wherein one or both of pentaerythritol ester (antioxidant 1010), three (2, the 4-di-tert-butyl-phenyl) phosphorous acid esters (oxidation inhibitor 168), two (octadecyl) pentaerythritol diphosphites (oxidation inhibitor 618) or MALEIC ANHYDRIDE;

The biodegradable full starch plastics of fully biodegradable, its weight of elastomer material % are:

One or more various types of starch and modified starch 90-50

Softening agent 10-50

Extender plasticizer 0-20

Thermo-stabilizer 0.5-9

The melt blending process: starting material just mix in homogenizer in proportion in advance, and mixing in Banbury mixer then, melting temperature is 50-160 ℃, and mixing time is 5-20min, Banbury mixer rotating speed 20-50rpm/min; Its twin screw is extruded processing conditions: temperature in 50-120 ℃, the mixing section temperature is 70-150 ℃, and the fluxing zone temperature is 85-165 ℃, and extrusion temperature is 65-130 ℃, and screw speed is 80-120rpm/min.The products therefrom tensile strength is: 0.92-39.0MPa, elongation at break is: 4.1%-293%.