Degradable PBAT polymer regenerated from waste PBT and preparation and application thereof

Abstract

The invention relates to a degradable PBAT polymer regenerated from waste PBT as well as preparation and application of the degradable PBAT polymer. Firstly, a waste PBT material is taken as a raw material to be subjected to alcoholysis and filtered to obtain regenerated BHBT, and then the regenerated BHBT and BHAT are subjected to ester exchange polycondensation reaction to obtain the degradable PBAT polymer; phytic acid, sodium phytate or potassium phytate is added as a complexing agent during alcoholysis; the weight-average molecular weight of the prepared degradable PBAT polymer is 10000-80000, the melting point is 40-125 DEG C, the melt index measured under the conditions that the temperature is 190 DEG C and the load is 2.16 kg is 8-50 g / 10 min, the terminal carboxyl group content is 15-80 mmol / t, the chroma b value is 5-20, the intrinsic viscosity is 0.5-1.6 dL / g, and the 90-day biodegradation rate is 50-90%. According to the invention, the PBAT material which can be completely biodegraded is prepared through chemical alcoholysis and repolymerization, and the PBAT material can be used in many fields of packaging, tableware, agricultural films, biomedical polymer materials and the like.

Description

technical field [0001] The invention belongs to the technical field of recycling and reuse of waste materials, and relates to the regeneration of waste PBT into degradable PBAT polymer and its preparation and application. Background technique [0002] PBAT has good biodegradability and can be completely degraded by microorganisms in nature after use, and will become the mainstream degradable plastic product in the future. Compared with the traditional non-degradable plastic PE, the unit cost of PBAT is 26% higher, which is not conducive to its large-scale application and promotion in the domestic market. The reason is that the production cost of PBAT is higher than other degradable materials widely accepted by the market due to the high price of raw materials (PTA terephthalate, AA adipic acid and BDO 1,4-butanediol). [0003] Patent application CN202011580761.0 discloses a production device for regenerating recycled polyester into degradable material PBAT. The dried recycl...

AI Technical Summary

Problems solved by technology

However, this method cannot rectify and remove impurities during the alcoholysis process of polyester, and can only regenerate recycled polyester with a single component and less impurity materials. , by introducing metal ions such as zinc, magnesium, cobalt, tin and other alcoholysis catalysts to accelerate the alcoholysis reaction of polyester, but because the introduced alcoholysis catalyst itself is difficult to remove, the residual metal ions will affect the process of preparing new polyester. Product quality, such as difficult polymerization, yellowish product color or even serious degradation problems; in order to reduce the impact of existing metal ions and pigments on quality, small molecular monomers such as p-benzene Dimethyl diformate is polymerized after the flash distillation of small molecular monomers, although the purity of the product is improved, it inevitably brings high costs and is difficult to apply on a large scale; and in the prior art There is no technology to prepare high-quality degradable polymer PBAT after alcoholysis of polyester

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