The invention belongs to the technical field of polymer materials, and relates to a completely biodegradable masterbatch and a preparation method thereof. The fully biodegradable master batch is made of the following components in parts by weight: 70-95 parts of starch, 5-30-50 parts of pbat, 5-30 parts of plasticizer, 0.5-3 parts of compatilizer, 0.05-2 parts of initiator, 0.5-5 parts of hydrophobic modifier, 0-0.6 parts of lubricant and 0. 1.6 antioxidant. The fully biodegradable master batch provided by the invention not only has good thermoplasticity, good processability and good dispersion effect in polymer matrix, but also has low water absorption performance, which can ensure the mechanical properties of the material during long-term storage; When added to biodegradable polyester, the preparation cost of the mixture can be greatly reduced.
This patent describes a completely biodegradable masterbatch and its preparation method.
Technical field
[000 1] The invention belongs to the technical field of polymer materials, and relates to a completely biodegradable master batch and a preparation method thereof.
technical background
[0002] The use of plastic film has penetrated into all fields of people's lives, and is widely used as food packaging, electronic and electrical product packaging, shopping bags and garbage bags in shopping malls. Traditional plastic film materials, such as polypropylene (PP) film and polyethylene (PE) film, are all made of petroleum, which is difficult to degrade after being abandoned in nature, causing great harm to the environment. With the exhaustion of petroleum resources and the enhancement of people's awareness of environmental protection, it has become the mainstream in the future to develop fully degradable and environmentally friendly polymer materials as film materials.
[0003] Polylactic acid (PLA), polybutylene succinate (PBS), poly (butylene terephthalate-co-butylene adipate) (PBAT), polyhydroxyalkanoate (PHA), etc. All of them are biodegradable and can be completely degraded into water and carbon dioxide after use. Therefore, it can be widely used in the field of plastic films and reduce the environmental pollution caused by the use of traditional films. However, the price of these biodegradable materials is high, and the prepared films are not competitive compared with traditional films.
[0004] Starch widely exists in plants in nature, which is rich in resources, low in price and biodegradable. Therefore, by adding starch to biodegradable polyester, the prepared mixture can not only achieve complete biodegradation, but also reduce the preparation cost of the mixture and increase its market competitiveness.
[0005] One method of adding starch to high molecular weight polyester is to directly mix starch, plasticizer and various processing AIDS with polyester in a high mixer, and then add them to a screw machine for extrusion granulation to obtain a * * * mixture, as described in patent CN 13 15927. Due to the poor thermoplasticity of untreated starch, it is difficult to process, so plasticizer should be added to plasticize it at the same time to improve the processing performance of starch. However, due to the existence of a large number of high molecular weight polyesters in the above processing methods, starch is easily plasticized unevenly, resulting in poor dispersibility in polyester. In order to improve the processability and dispersibility of starch in polyester, starch can be made into thermoplastic starch masterbatch and then mixed with high molecular weight polyester to obtain a biodegradable mixture. Therefore, the properties of thermoplastic starch masterbatch have great influence on the properties of the final mixture. One of the most important problems is the high water absorption of starch, and in order to improve the plasticity of starch, the added polyol plasticizer makes the prepared thermoplastic starch more water-absorbent, which will obviously reduce the mechanical properties of biodegradable polyester * * * mixture containing starch with the extension of storage time. Patent CN 10 1328285 and patent cn10122517 use two monomers with reactive end groups and hydrophobic alkyl chains to react with starch for hydrophobic treatment, which can significantly reduce the water absorption of modified starch, but the obtained starch has poor plasticity.
Summary of the invention
[0006] In order to overcome the shortcomings of the prior art, the invention aims to provide a completely biodegradable master batch and a preparation method thereof. ..
[0007] In order to achieve the above purpose, the present invention adopts the following technical scheme:
[0008] A completely biodegradable master batch is prepared from the following components in parts by weight:
[0009]
claim of right
1. A completely biodegradable masterbatch is characterized by comprising the following components in parts by weight:
2. The biodegradable master batch according to claim 1, characterized in that the starch is one or more of potato starch, corn starch, cassava starch or wheat starch.
3. The completely biodegradable master batch according to claim 1, characterized in that the weight average molecular weight of the poly (butylene terephthalate-co-butylene adipate) ester is 20000- 130000.
4. The completely biodegradable master batch according to claim 1, characterized in that the plasticizer is one or more of ethylene glycol, propylene glycol, glycerol, sorbitol, urea, formamide or acetamide.
5. The completely biodegradable masterbatch according to claim 1, characterized in that the compatibilizer is one or more of maleic anhydride and maleic anhydride grafted ethylene-octene polymer.
6. The biodegradable masterbatch according to claim 1, characterized in that the initiator is one or more of dicumyl peroxide or benzoyl peroxide; Or the hydrophobic modifier is a monomer with a long-chain aliphatic hydrocarbon and a reactive functional group, and is further preferably one or more of alkenyl succinic anhydride and alkyl ketene dimer.
7. The completely biodegradable master batch according to claim 1, characterized in that the lubricant is one or more of stearic acid, calcium stearate, oleamide, erucamide, paraffin wax or polyethylene wax.
8. The completely biodegradable master batch according to claim 1, characterized in that the antioxidants are tetrakis [β-(3,5-di-tert-butyl -4- hydroxyphenyl) propionic acid] pentaerythritol ester, β-(3,5-di-tert-butyl -4- hydroxyphenyl) propionic acid octadecyl alkyd ester and 2- propylene. Or the filler is one or more of calcium carbonate, kaolin, silica, mica, montmorillonite, clay, titanium dioxide, talcum powder, etc., and the particle size is preferably 1250 -8000 mesh, and further preferably 2000-3000 mesh.
9. The method for preparing a completely biodegradable master batch according to claim 1-8, characterized by comprising the following steps: (1) drying starch, poly (butylene terephthalate-co-butylene adipate) ester and filler; (2) Weighing the following raw materials in parts by weight: 70-95 parts of starch, 5-30 parts of polybutylene terephthalate-co-butylene adipate, 30-50 parts of plasticizer, 0.5-3 parts of compatilizer, 0.05-2 parts of initiator, 0.5-5 parts of hydrophobic modifier and 0.65438 part of lubricant. Uniformly mixing the raw materials in a high mixer; (3) adding the raw materials evenly mixed in step (2) into a twin-screw extruder for melting, mixing, extruding, stretching and granulating.
10. The preparation method according to claim 9, characterized in that the drying temperature of starch and polybutylene terephthalate-co-butylene adipate in step (1) is 60-80.d egree. C. and the drying time is 6-24 hours; The drying temperature of the filler is 100- 120℃ and the drying time is 5-10h; The drying equipment is a vacuum oven or a blast oven; Or the twin-screw extruder in step (3) is a co-rotating or counter-rotating twin-screw extruder, the extrusion temperature is 90-65438+/-060 DEG C, the screw speed is 60-300 rpm, and the length-diameter ratio L/D of the screw is 40-