Cardanol-modified poly(ethylene 2,6-naphthalate) (PEN) and preparation method thereof

Abstract

The invention relates to cardanol-modified poly(ethylene 2,6-naphthalate) (PEN) and a preparation method thereof, belonging to the field of high molecular materials and synthesis. The method comprisesthe following steps: taking poly(ethylene 2,6-naphthalate) as a raw material, adding ethylene glycol and cardanol, taking anhydrous zinc acetate as a main catalyst and nano titanium dioxide as an auxiliary catalyst to perform ester exchange and polycondensation reaction, and depressurizing by stages after polycondensation to obtain the cardanol-modified poly(ethylene 2,6-naphthalate). A phenolichydroxyl group in cardanol participates in ester exchange reaction to form an end-capping structure of PEN polyester, unsaturated double bonds generate crosslinking in the process of thermal forming,and the heat resistance of the PEN polyester is improved. By introducing the cardanol, the dosage of expensive PEN can be reduced, the required production time for obtaining PEN polyester with excellent enough performance is shortened, and the cost is lowered when the performance is improved simultaneously.

Description

technical field [0001] The invention belongs to the technical field of polymer materials and their synthesis, and in particular relates to cardanol-modified polyethylene-2,6-naphthalene dicarboxylate and a preparation method thereof. Background technique [0002] Since 1998, the pattern of the world's polyester industry has undergone tremendous changes. Europe and the United States have shifted from polyester fiber production to new technology and new products to develop new markets for polyester products. Asia has imported polyester Fiber turned to become the world's largest polyester production base. In 2015, China's polyester production capacity has increased to 47.58 million tons, and the overcapacity situation is serious. At the same time, under the influence of the weak global economy and the anti-dumping investigations in Europe and the United States, China's polyester product exports have fallen sharply. In the same year, China's polyester bottle flake exports The t...

AI Technical Summary

Problems solved by technology

In 2016, the export volume of China's PET bottle flakes rebounded, but the anti-dumping incident continued to escalate, resulting in a decline in the competitive advantage of export prices, serious product homogeneity, and vicious price competition among domestic manufacturers, resulting in record low average product prices and profit margins

The direct esterification method has fewer steps, no methanol by-products, and higher product viscosity. However, the direct esterification method has higher requirements on the purity of 2,6-naphthalene dicarboxylic acid. If the purity cannot reach more than 99%, high molecular weight PEN cannot be obtained. polyester

2,6-naphthalene dicarboxylic acid is insoluble in most solvents, and it is not easy to melt, and it will decompose above 300°C, making it difficult to purify, which makes industrial production difficult

In the transesterification method, due to the presence of residual methyl ester groups, it is necessary to prolong the reaction time and increase the reaction temperature to obtain PEN polyester with a sufficiently high viscosity, which will bring about problems such as increased side reactions and increased costs.

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