First, DMT and CHDM undergo transesterification to generate bishydroxymethylcyclohexanemethylterephthalate (BHMCT) and other low molecular weight PCT polymers and methanol, usually with Titanium, manganese, cobalt and sodium catalysts to increase conversion rates in transesterification and polymerization reactions. Then, through pre-polycondensation reaction, low relative molecular mass oligomers or polymers are generated, and CHDM is released. At this point, the catalyst/initiator system is added to accelerate the polymerization and terminate the transesterification reaction. After the final polymerization process, the product PCT is obtained.
Overseas research on PCT began as early as the 1950s. The American Eastman Company, the German Huls Company, etc. have participated in the research and have applied for patents. In recent years, the process research trend of PCT and its derivative polyester has been from DMT method to PTA method. The research direction is mainly to find reasonable and economical production process paths and formulas, as well as to improve and optimize the indicators of polyester products.
Eastman Chemical Company of the United States is the only manufacturer of PCT pure resin in the world. Some scientific research units in my country are also conducting research on the synthesis of PCT, but they do not yet have the technology to build industrialized equipment. Therefore, the current domestic construction of this project requires the introduction of technology.