CN101864184B - Thermoplastic vegetable fiber/starch blending material and preparation method thereof - Google Patents

Abstract

The invention discloses a thermoplastic plant fiber/starch blend material and a preparation method thereof. The weight ratio of each component is: thermoplastic plant fiber 1-99, thermoplastic starch 1-99, crosslinking agent 0-10, plasticizer 0-10. Its preparation is to stir the raw materials in a high-speed mixer for 5-20 minutes, dry at a temperature of 30-60°C for 8-12 hours, and control the temperature at 100-140°C to melt and blend the blended materials in a twin-screw extruder. 5 ~ 10 minutes, granulation at 110 ~ 150 ° C, 0.1 ~ 1MPa to obtain the product. The product of the invention has good processing performance, and has excellent thermoplastic processing characteristics and mechanical properties in the process of extrusion molding, blow molding, injection molding and foaming. , electromechanical, building materials, packaging and environmental protection and other production and processing fields.

Description

Thermoplastic plant fiber/starch blend material and preparation method thereof

(1) Technical field The present invention relates to the present invention relates to thermoplastic plant fiber/starch blend material and preparation method thereof.

(2) Background technology Every year, 150 million tons of limited petrochemical resources such as oil and natural gas are used to chemically synthesize "synthetic polymers". The sustainable development of human society has become the consensus of all countries in the world. To achieve the sustainable development of the world economy, one of the frontiers of related research at home and abroad is to use clean production technology to modify and synthesize renewable biomass resources into environmentally friendly polymer materials that meet the requirements of use, reducing the impact on limited resources. Consumption, to reduce the pollution of the environment after the use of materials, for this reason, related research at home and abroad pays more attention to finding new natural polymer plastic materials.

Plant fiber is a huge regenerative biopolymer resource on the earth. Starting from the sustainable utilization of resources, protection of the environment, and the characteristics of biocompatibility and biodegradability, people place great expectations on the utilization of renewable plant fibers. Thus, the resource utilization of plant fibers and the development of environmentally friendly green products have formed a hot field in the research and development of environmentally green high-tech. As a renewable resource, the modification and utilization of plant fiber can save a lot of petroleum resources on the one hand, and alleviate the environmental pollution caused by a large amount of non-degradable synthetic polymer waste. Realize the cycle of biomass in the natural environment.

Starch is a natural polymer material with abundant sources and low price, and it is an inexhaustible renewable resource. Starch has the characteristics of being renewable, cheap, easy to store and easy to transport. Under certain conditions, it can undergo various reactions and derive many derivatives. The good availability and biodegradability of starch make it a good raw material for biodegradable materials. Starch-based derivative materials can be biodegraded in a variety of environments, and the final degradation products CO2 and H2O can be recycled through photosynthesis. will cause any pollution to the environment. Over the years, countries all over the world have attached great importance to the research and development of starch-based thermoplastic materials, but thermoplastic starch melt has poor performance, and there are difficulties in processing and application. It is very difficult to implement processing methods such as blow molding, calendering, injection molding and spinning, and it is difficult to process products that meet the requirements of use on conventional polymer processing equipment through conventional processing methods.

The new thermoplastic blend material obtained after thermoplastic plant fiber and starch melt blending modification has good processing performance, and has excellent thermoplastic processing characteristics and mechanical properties in the process of extrusion, blow molding, injection molding and foaming. Its products are used After being completely degraded and environmentally friendly, it can be widely used in the production and processing fields of chemical industry, agricultural mulch film, electromechanical, building materials, packaging and environmental protection.

(3) Contents of the invention

1. Purpose of the invention The purpose of the present invention is to provide an environmentally friendly thermoplastic plant fiber/starch blend material and its preparation method. The blending of thermoplastic plant fiber/starch can improve the processing performance of thermoplastic plant fiber, and at the same time, it can have a good plasticizing effect on starch, and solve the problems of insufficient starch processing performance, toughness and tear resistance, low elongation at break, and thin films. Brittleness and other problems, provide a new method of producing environmentally friendly plant fiber/starch thermoplastic materials using natural plant fibers as raw materials, and serve for the large-scale development and utilization of renewable resource plant fibers.

2. Technical solution The technical solution of the present invention is:

The invention relates to a thermoplastic plant fiber/starch blended material, the weight ratio of each component of which is: thermoplastic plant fiber 1-99, thermoplastic starch 1-99, crosslinking agent 0-10, plasticizer 0-10. The thermoplastic plant fiber is prepared by crushing and expanding the plant fiber raw material after removal of impurities, adding 1% H2SO4 solution twice the weight of the plant fiber, treating at 120° C. for 1 hour, filtering, cleaning, drying, and pulverizing through a 40-mesh sieve. Obtain the pure plant fiber powder that removes lignin and pentosan; Add 3 times of 18% NaOH solution to the pure plant fiber powder, dip for 2h at 30°C, press to squeeze out excess lye, so that the plant fiber contains The lye is controlled at 50% to obtain alkalized plant fibers; take 100 parts of alkalized plant fibers, 2 parts of potassium persulfate, and 200 parts of methyl acrylate in the reaction kettle by weight, and feed N2 at the same time, stirring at 30 ° C React for 10 hours, add 10% acetic acid solution to neutralize to pH 7.0 after the material is in a slurry form; the reaction solution is removed by centrifugation, and the obtained solid is washed to neutral and then vacuum-dried to obtain a thermoplastic plant fiber; the thermoplastic The starch is 100 parts by weight of starch, 15 parts of glycerin, 20 parts of maleic anhydride, 0.035 parts of tert-butyl peroxide, 3 parts of dioctyl maleate and 16 parts of water, and mix and stir in a high-speed mixer Finally, melt blending and grafting reaction is carried out through an extruder at 140°C to 160°C, and extrusion granulation after the reaction is completed to obtain thermoplastic starch; the crosslinking agent is selected from maleic anhydride, tributyl citrate , ethylene bis stearic acid amide, hexagonal boron nitride, or any combination of two or more; the plasticizer is selected from glycerol, polyethylene glycol, dibutyl phthalate, hexagonal One or any combination of two or more dibutyl diacids.

A kind of method for preparing thermoplastic plant fiber/starch blended material, its concrete steps are:

The first step, ingredients: take thermoplastic plant fiber 1~99, thermoplastic starch 1~99, crosslinking agent 0~10, plasticizer 0~10 according to weight ratio, stir and mix in a high-speed mixer for 5~20min .

The second step, drying: the homogeneously mixed blend is dried at a temperature of 30-60°C for 8-12 hours.

The third step, blending and granulation: Melt and blend the dried blended material in a twin-screw extruder at 100-140°C for 5-10 minutes, extrude and granulate at 110-150°C and 0.1-1MPa, Prepare thermoplastic plant fiber/starch blend material.

3. Beneficial effects As a renewable natural resource, plant fiber has sufficient sources and is biodegradable. By blending and modifying it, a new thermoplastic plant fiber/starch blend material with plant fiber as the skeleton can be obtained. As a renewable resource, its blending modification and utilization can save a lot of petroleum resources on the one hand, and on the other hand can alleviate the environmental pollution caused by a large amount of non-degradable synthetic polymer waste. Biomass recycling can be achieved in the natural environment. The blending modification of thermoplastic plant fiber and thermoplastic starch has good compatibility and can reach a state of thermodynamic compatibility, avoiding the phase separation of the product, and improving the stability of the performance of the modified product. The blending modification of thermoplastic plant fiber and thermoplastic starch makes its processing rheological properties similar to that of polyethylene, which is convenient for industrial production with conventional equipment. The blended modified product of thermoplastic plant fiber and thermoplastic starch has excellent comprehensive mechanical properties, and its products are completely degradable and environmentally friendly after use. They can be widely used in the production and processing fields of chemical industry, agricultural mulch film, electromechanical, building materials, packaging and environmental protection.

(4) Specific implementation methods

The present invention will be further described in detail below in conjunction with the examples, wherein the parts of raw materials are all parts by weight unless otherwise specified.

Example 1: Take 1 part of thermoplastic plant fiber, 99 parts of thermoplastic starch, and 1 part of maleic anhydride in a high-speed mixer for 5 minutes, dry at a temperature of 30 ° C for 12 hours, and control the temperature at 100 ° C. The mixture was melt-blended in a twin-screw extruder for 5 minutes, and pelletized at 110° C. and 1 MPa to obtain a fully biodegradable thermoplastic plant fiber/starch blend material.

Example 2: Take 99 parts of thermoplastic plant fiber, 1 part of thermoplastic starch, and 10 parts of dibutyl phthalate according to the weight ratio, stir in a high-speed mixer for 20 minutes, dry at a temperature of 60°C for 8 hours, and control the temperature at 140°C The blended material was melt-blended in a twin-screw extruder for 10 minutes, and pelletized at 150° C. and 0.1 MPa to obtain a fully biodegradable thermoplastic plant fiber/starch blended material.

Embodiment 3: get 10 parts of thermoplastic plant fibers, 90 parts of thermoplastic starches by weight, 3 parts of tributyl citrate and 3 parts of glycerol, 7 parts of Polyethylene Glycol are stirred in high-speed mixer 8 minutes, at temperature Dry at 40°C for 10 hours, blend the melt blended material in a twin-screw extruder at 110°C for 6 minutes, and granulate at 120°C and 0.7 MPa to obtain a fully biodegradable thermoplastic plant fiber/starch blend material.

Example 4: Take 30 parts of thermoplastic plant fiber, 70 parts of thermoplastic starch, 5 parts of ethylene bis stearic acid amide and 3 parts of dibutyl adipate by weight, stir in a high-speed mixer for 10 minutes, and dry at a temperature of 45 ° C For 12 hours, the blend was melt-blended in a twin-screw extruder at 120°C for 7 minutes, and granulated at 130°C and 0.5 MPa to obtain a fully biodegradable thermoplastic plant fiber/starch blend material.

Embodiment 5: Take 50 parts of thermoplastic plant fiber, 50 parts of thermoplastic starch, 7 parts of hexagonal boron nitride and 5 parts of polyethylene glycol by weight, stir in a high-speed mixer for 15 minutes, and dry at a temperature of 35 ° C for 12 hours. The blended material was melt-blended in a twin-screw extruder at 130° C. for 8 minutes, and pelletized at 140° C. and 0.3 MPa to obtain a fully biodegradable thermoplastic plant fiber/starch blended material.

Embodiment 6: Get 70 parts of thermoplastic plant fibers, 30 parts of thermoplastic starch, 5 parts of tributyl citrate, 5 parts of ethylene bis stearic acid amide and 7 parts of glycerol by weight and stir in a high-speed mixer for 12 minutes , dried at 50°C for 8 hours, controlled temperature at 140°C, melt blended the blended material in a twin-screw extruder for 9 minutes, and granulated at 150°C and 0.2MPa to obtain a fully biodegradable thermoplastic plant fiber/starch blend Material.

Claims (4)

1. a thermoplastic vegetable fiber is characterized in that, the weight part proportioning of its each component is: thermoplastic plant fiber 1～99, thermoplastic starch 1～99, linking agent 0～10, softening agent 0～10; Described thermoplastic plant fiber is that the plant fiber material after the impurity elimination is pulverized, and is expanded; The 1%H that adds 2 times of vegetable fibre weight ₂SO ₄Solution is handled 1h down at 120 ℃; Filter, clean, dry, pulverized 40 mesh sieves, obtain removing the pure plant fiber powder of lignin and pentosan; The 18%NaOH solution that in pure plant fiber powder, adds 3 times, at 30 ℃ of dipping 2h down, squeezing is squeezed and is removed unnecessary alkali lye, makes to contain alkali lye in the vegetable fibre and be controlled at 50%, promptly obtains the alkalization vegetable fibre; Get 200 parts of alkalization 100 parts on vegetable fibre, 2 parts of Potassium Persulphates, methyl acrylates by weight in reactor, feed N simultaneously ₂, 30 ℃ of following stirring reaction 10h are to material and add 10% acetum behind the pulpous state and be neutralized to pH7.0; Reaction solution is removed solution by centrifugation, and the gained solid is drying to obtain thermoplastic plant fiber through being washed to neutral final vacuum; Described thermoplastic starch is to get 16 parts in 100 parts of starch, 15 parts of glycerine, 20 parts of maleic anhydrides, 0.035 part of tert-butyl peroxide, 3 parts of dioctyl maleates and water by weight, after high speed mixing roll mixing stirring, carry out the melt blending graft reaction at 140 ℃～160 ℃ by forcing machine, the extruding pelletization after reaction finishes obtains thermoplastic starch.

2. thermoplastic vegetable fiber according to claim 1 is characterized in that, described linking agent is a MALEIC ANHYDRIDE, the arbitrary combination of one or more in tributyl citrate, ethylene bis stearic acid amide, the hexagonal boron nitride.

3. thermoplastic vegetable fiber according to claim 1 is characterized in that, described softening agent is a glycerol, polyoxyethylene glycol, dibutyl phthalate, the arbitrary combination of one or more in the Polycizer W 260.

4. prepare the method for the described thermoplastic vegetable fiber of claim 1, the steps include:

The first step, batching: by weight proportioning heat-obtaining plasticity vegetable fibre 1～99, thermoplastic starch 1～99, linking agent 0～10, softening agent 0～10, stirring and evenly mixing 5～20min in high-speed mixer;

Second step, drying: with the blend that mixes 30～60 ℃ of dryings of temperature 8～12 hours;

In the 3rd step, the blend granulation: in 100～140 ℃ of melt blending 5～10min, extruding pelletization under 110～150 ℃, 0.1～1MPa is prepared into thermoplastic vegetable fiber to the blend composition that drying is good in twin screw extruder.