A kind of production technology of high amylose/polylactic acid composite material masterbatch method

Abstract

The invention discloses a master batch method production technology of a high amylose starch / polylactic acid composite material. The production technology comprises following steps: (1.1) preparing following components in parts by weight: 90 to 110 parts of corn starch, 20 to 40 parts of poly(butylene succinate), 1 to 3 parts of maleic anhydride or itaconic acid, and 3 to 5 parts of auxiliary agent; (1.2) selecting a high speed mixing machine set; (1.3) adding the corn starch into the reactor of the high speed mixing machine set, adding pullulanase and n-butanol, and preparing high amylose starch; (1.4) adding poly(butylene succinate), maleic anhydride or itaconic acid, and an auxiliary agent into the reactor, and carrying out gelatinization until the mixture is in a wire-drawing state; (1.5) discharging the mixture from the reactor; (1.6) transferring the mixture to the grinding machine of the high speed mixing machine set, and grinding the mixture to obtain required master batch; (2.1) mixing 90 to 110 parts of master batch and 90 to 110 parts of polylactic acid; and (2.2) adding the mixture into an extrusion injection molding machine, ejecting the mixture, and carrying out injection molding to obtain the product. The technology is simple and environmentally friendly.

Description

technical field [0001] The invention relates to the technical field of high-amylose / polylactic acid composite material production technology, in particular to a fully biodegradable high-amylose / polylactic acid composite material masterbatch production process. Background technique [0002] Since the early 1990s, the main materials for the production of disposable tableware are still PS foam materials, PP, PP / CaCO 3 , PP / talc powder, with the emergence of corn starch and thermoplastic composite materials, has attracted much attention all over the world because of its good environmental friendliness. Especially around 2000, disposable tableware produced from cornstarch / polylactic acid composite materials became the focus of new product investment and development in various places, and its production process mainly adopts the masterbatch method. But unfortunately, after just over ten years, the original hot products did not bring the expected upsurge in the market. The main r...

AI Technical Summary

Problems solved by technology

[0006] First, the brittleness of the product is high. The brittleness of the disposable tableware produced by masterbatch is relatively large, especially in the direction of flow, so that it is difficult to meet the requirements of use, and the brittleness is more manifested in the product as the storage time increases. increased by extension;

[0007] Second, the starch content is low. The starch content of the masterbatch method technology is below 45%, which cannot meet the requirements of the composting experiment, resulting in low biodegradation rate and poor composting effect

If the starch content is deliberately increased, the molecular weight of the product material is too low, and the nucleation is fast and the processability is poor, resulting in uneven structure of the product, low transparency and strength, and greater brittleness of the product;

[0008] Third, it is difficult to pelletize the production masterbatch, because the polylactic acid graft continues to form in the twin-screw extruder, and the graft is also accompanied by the generation of cross-linked matter. In order to ensure a certain fluidity, it is necessary to Add a large amount of low-molecular wax, so that the extruded strips will be more brittle, making it difficult to pelletize the masterbatch;

[0009] Fourth, the evaporation residue is too high. The amount of evaporation residue is an important technical indicator. If the product cannot meet the standard, it cannot enter the market

For the disposable tableware produced by this masterbatch method, the evaporation residue of the product is much higher than the national standard. In order to solve this problem, many companies have adopted many methods, and some companies even sprayed a layer of polylactic acid film on the product in order to achieve National standard, but this obviously adds to the manufacturing cost

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