CN102268097B

CN102268097B - Preparation method of thermoplastic fully-degradable corn starch matrix

Info

Publication number: CN102268097B
Application number: CN 201110141145
Authority: CN
Inventors: 袁怀波; 马莉莎; 高翠平
Original assignee: Hefei University of Technology
Current assignee: Hefei University of Technology
Priority date: 2011-05-30
Filing date: 2011-05-30
Publication date: 2012-12-19
Anticipated expiration: 2031-05-30
Also published as: CN102268097A

Abstract

The invention relates to a preparation method of a thermoplastic fully-degradable corn starch matrix, which comprises the following steps: carrying out micro-pulverization on corn starch, and adding water until the water content of the corn starch reaches 20%; mixing the corn starch (of which the water content is 20%), citric acid and glycerol in a mass ratio of 1:0.4:0.3, and evenly stirring at high speed; carrying out esterification reaction on the mixture to obtain a viscous esterified substance; and flushing the esterified substance with water twice, drying and pulverizing to obtain the light yellow powdery thermoplastic fully-degradable corn starch matrix. The particle size of the corn starch is made small by micro-pulverization, and the corn starch sufficiently contacts with the modifiers; since the actions of heat and shearing force on the particles are relatively obvious and sufficient, the temperature during reaction can be easily reached and controlled, thereby shortening the reaction time; the special phenomenon of partial esterification appears in the reaction process, so the anabiosis can be prevented, thereby facilitating long-term storage of the corn starch matrix. The modifiers used in the invention are innoxious and fully-degradable, thereby widening the application range of the corn starch matrix.

Description

The high-fall preparation method who separates W-Gum matrix of a kind of thermoplasticity

Technical field

The present invention relates to the two high-fall preparing methods that separate W-Gum matrix of modified thermoplastic of a kind of mechanical force and Hydrocerol A.

Background technology

Thermoplastic starch (TPS) is a starch in hydrogen bond and the crystalline texture destroyed under properties-correcting agent and heat and the shear action between starch molecule, makes its fusion that can before decomposition, reach crystallite, thereby but thermoplastic is processed into material uses.

The preparation of thermoplasticity W-Gum at present mainly contains following several method: 1. W-Gum is dispersed in water or the organic solvent; Be made into the suspension-s that concentration is 35%-45%; Hydro-oxidation sodium and Monochloro Acetic Acid are in milk of starch; React with chemical reagent being lower than under the gelatinization point condition, obtain product through filtration, cleaning, drying then; 2. having prepared thermoplastic starch (TPS) with methane amide as fluidizer, 3. is that raw material only adds Hydrocerol A with the W-Gum, and the glycerin modification agent prepares the thermoplasticity W-Gum; 4. use W-Gum, Z 150PH (PVA), glycerine are raw material, Hydrocerol A as additive and LUTARALDEHYDE as the linking agent hybrid process; 5. W-Gum and fluidizer being added rotating speed according to the ratio of mass ratio 1: 0.2～0.35 is to mix in 1000～4000 rev/mins of high-speed mixers; Mixed 5 minutes; Then with mixture be sealed in the plastics bag place after 24 hours subsequent use; According to the ratio of mass ratio 1: 0.01～0.05, with polyvinyl alcohol water solution and polynite in container under 80 ℃ of temperature violent stirring 6～10 hours, place after 24 hours the mixing solutions sealing subsequent use then; After mixture mixes mixture is put into the twin screw compounding forcing machine and extrude, promptly process thermoplastic starch material; 6. utilizing twin screw extruder that W-Gum is carried out gelatinization and handle, after drying, pulverizing, make pre-gelatinized starch, is raw material with it, adds glycerine, and PVA is that softening agent prepares thermoplastic starch; 7. the method for preparing hydrophobic thermoplastic starch with octenyl succinic acid anhydride; At first in the ratio of mass ratio 100: 0.1～10; Starch joined with octenyl succinic acid anhydride (ASA) mix 2～10 minutes in the high-speed mixer; The mixture sealing was placed 4～12 hours, extrude, process hydrophobic thermoplastic starch through the screw rod plastic forcing machine; 8. in the presence of glycerine, urea and water, W-Gum can be processed into thermoplastic starch etc. in Banbury mixer.There is following problem respectively in above-mentioned eight kinds of preparing methods: do not occur there is not strong interaction between special partial esterification, starch and the softening agent in method 1, the method 2, the preservation period of prepared W-Gum matrix is shorter relatively.Do not use superfine communication technique in the method 3, softening agent is abundant inadequately with contacting of starch, and the Zhi Huadu of prepared W-Gum matrix is the highest to be merely 0.23.Used Z 150PH (PVA) in method 4, method 5, the method 6, this material can not be degraded fully, is unfavorable for protecting environment.Used octenyl succinic acid anhydride in the method 7, and these material price rate of exchange are expensive, the cost of prepared W-Gum matrix is than higher.Used urea in the method 8, urea is to use food, aspects such as medicine.

Summary of the invention

In order to overcome the deficiency that above-mentioned existing W-Gum matrix preparation method exists, the present invention provides the product that a kind of technology is simple, the reaction times is short, cost is low, prepare to preserve long and the wider high-fall preparation method who separates W-Gum matrix of thermoplasticity of use range.

The technical solution that realizes above-mentioned purpose is following:

The high-fall preparation method who separates W-Gum matrix of a kind of thermoplasticity comprises following operation steps:

(1), with the W-Gum micronizing, the diameter that makes corn starch granules is about the 58-66 micron, adds entry and makes the water cut of W-Gum reach 20%;

(2), W-Gum 25 grams, Hydrocerol A 10 grams, glycerine 7.5 grams of getting water cut 20% mix by mass ratio 1:0.4:0.3; Under 1500～3000 rev/mins of conditions of rotating speed, high-speed stirring 3-5 minute, get mixture; Mixture is put into sealing bag, and sealing was placed 24 hours;

(3), esterification: mixture is heated while stirring, 120 ℃ of temperature, esterification 60 minutes, the carboxylate of sticky shape, cool to room temperature;

(4), with carboxylate with zero(ppm) water suction filtration flushing twice, the unreacted Hydrocerol A of flush away, the material after the distillation washing is dry under 50 ℃ of conditions, dry thing, with dry thing pulverizing, obtain the high-fall W-Gum matrix of separating of micro-yellow powder shape thermoplasticity.

The present invention and existing eight kinds of advantages that the preparation method compares and has: do not occur not having between special partial esterification, starch and the softening agent strong interaction in method 1, the method 2; And strong interaction between special partial esterification, starch and the softening agent appears among the present invention; Partial esterification and can better prevent to bring back to life the long-time preservation of the W-Gum matrix that is more conducive to make by force alternately.Do not use superfine communication technique in the method 3, softening agent is abundant inadequately with contacting of starch, and the Zhi Huadu of product is the highest to be merely 0.23; And used superfine communication technique among the present invention; Starch granules diminishes, and has increased contacting of softening agent and starch granules, has strengthened the interaction between softening agent and the starch; Make reaction efficiency higher and Zhi Huadu reaches as high as 0.346, be more conducive to prolonged preservation.Used Z 150PH (PVA) in method 4, method 5, the method 6; This material can not be degraded fully; And do not use Z 150PH (PVA) among the present invention; Degradation property ratio method 4, method 5, the method 6 prepared products of the W-Gum matrix that therefore makes must be got well, and are more conducive to protect environment.Used octenyl succinic acid anhydride in the method 7, and these material price rate of exchange are expensive, so cost is than higher; Used urea in the method 8, urea cannot use aspects such as food, medicine; What use among the present invention all is non-toxic substance, makes to such an extent that application range of products is wider.

The present invention has adopted superfine communication technique, is about 101 microns without the diameter of the corn starch granules of micronizing, and the diameter of corn starch granules is about 62 microns after the micronizing; Starch granules diminishes, and is beneficial to starch granules and fully contacts with properties-correcting agent, has strengthened the interaction between softening agent and the starch; Also be beneficial to simultaneously heat and shearing force to the particulate effect, avoided reagent effective consumption and the low problem of utilization ratio, simultaneously; Temperature ratio during reaction is easier to reach and control, and the reaction times is also shorter, has occurred special partial esterification phenomenon in the reaction process; Can prevent to bring back to life the W-Gum matrix prolonged preservation of being convenient to make.The high-fall Zhi Huadu of separating W-Gum of thermoplasticity of the present invention is 0.346, and the single modified thermoplastic W-Gum Zhi Huadu that only adds Hydrocerol A, glycerin modification agent is 0.258, and whole preparation process does not have the discharge of industrial sewage, belongs to environmental protection and saving type technology.

Embodiment

Below in conjunction with embodiment the present invention is done to describe further.

Embodiment 1:

The high-fall preparation method who separates W-Gum matrix of thermoplasticity comprises following operation steps:

With conventional corn starch micronizing, the diameter that makes corn starch granules is the 58-64 micron;

To add in the closed reactors through 500 kilograms of W-Gums of micronizing and 125 kilograms of zero(ppm) water and mix, and make the water cut of W-Gum reach 20%; Add 250 kilograms of Hydrocerol As, 187.5 kilograms of glycerine then, under 3000 rev/mins of conditions of rotating speed, 3 minutes thorough mixing of high-speed stirring were placed 24 hours in closed reactor; In 120 ℃ of following heated and stirred of temperature 60 minutes, esterification, the carboxylate of sticky shape, reaction finishes cool to room temperature, the carboxylate of sticky shape; With zero(ppm) water suction filtration flushing twice, the unreacted Hydrocerol A of flush away, the material after distillation is washed are dry under 50 ℃ of conditions, get dry thing, and dry thing is pulverized, and obtain the high-fall W-Gum matrix of separating of micro-yellow powder shape thermoplasticity with carboxylate.Can use through technological formings such as extruding.

Embodiment 2:

To add in the closed reactors through 1000 kilograms of W-Gums of micronizing and 250 kilograms of zero(ppm) water and mix, and make the water cut of W-Gum reach 20%; Add 500 kilograms of Hydrocerol As, 375 kilograms of glycerine then, under 1500 rev/mins of conditions of rotating speed, 5 minutes thorough mixing of high-speed stirring.

Other step is with embodiment 1.

Embodiment 3:

To add in the closed reactors through 600 kilograms of W-Gums of micronizing and 150 kilograms of zero(ppm) water and mix, and make the water cut of W-Gum reach 20%; Add 300 kilograms of Hydrocerol As, 225 kilograms of glycerine then, under 2000 rev/mins of conditions of rotating speed, 4 minutes thorough mixing of high-speed stirring.

Other step is with embodiment 1.

Claims

1. high-fall preparation method who separates W-Gum matrix of thermoplasticity is characterized in that comprising following operation steps:

1.1, with the W-Gum micronizing, making the diameter of corn starch granules is the 58-66 micron, adds entry and makes the water cut of W-Gum reach 20%;

1.2, W-Gum 25 gram, Hydrocerol A 10 grams, glycerine 7.5 grams of getting water cut 20% mix by mass ratio at 1: 0.4: 0.3; Under 1500～3000 rev/mins of conditions of rotating speed, high-speed stirring 3-5 minute, get mixture; Mixture is put into sealing bag, and sealing was placed 24 hours;

1.3, esterification: mixture is heated while stirring, 120 ℃ of temperature, esterification 60 minutes, the carboxylate of sticky shape, cool to room temperature;

1.4, with carboxylate with zero(ppm) water suction filtration flushing twice, the unreacted Hydrocerol A of flush away, the material after the distillation washing is dry under 50 ℃ of conditions, dry thing, with dry thing pulverizing, obtain the high-fall W-Gum matrix of separating of micro-yellow powder shape thermoplasticity.