A thermoplastic copolyester composition with thermally reversible chemical crosslinking properties and its preparation and application

Abstract

The invention discloses a thermoplastic copolyester composition with thermally reversible chemical crosslinking properties and a preparation method and application thereof. The copolyester contains a side functional group, namely 2-furfuryl sulfenyl, and is prepared from dibasic acid or dibasic acid ester containing 2-furfuryl sulfenyl, dibasic acid and dibasic alcohol by a melting copolycondensation method. The 2-furfuryl sulfenyl of the copolyester and a crosslinking agent containing maleimide can carry out Diels-Alder cycloaddition reaction at 50-70 DEG C to realize chemical crosslinking and can realize decrosslinking at high temperature, thereby being convenient for recovery and secondary processing and utilization of the materials and realizing a self-repairing or shape memory function of the materials. The thermally reversible crosslinking copolyester designed in the invention has a saturated main chain structure, has excellent thermal stability and mechanical properties, is not easy to generate an irreversible crosslinking structure in thermal processing and life-time service processes of the materials, and can realize thermoplastic processing many times and keep the mechanical properties unchanged.

Description

technical field [0001] The present invention relates to a thermoplastic copolyester composition with thermally reversible chemical crosslinking properties and its preparation method and application, especially relates to utilizing the thermally reversible properties of Diels-Alder cycloaddition reaction to realize 2-furfurylsulfanyl side groups Thermally reversible crosslinking between the copolyester and the crosslinking agent containing maleimide groups to prepare a thermally reversible chemically crosslinked thermoplastic with good mechanical properties, recyclable reprocessing and self-healing Copolyester compositions. Background technique [0002] For polymers, chemical crosslinking structure and thermoplasticity are often a pair of contradictions, and it is difficult to coexist. Chemically crosslinked thermosetting polymers, the most common such as vulcanized rubber, have excellent mechanical properties and heat resistance, but the existence of chemically crosslinked ...

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Problems solved by technology

Chemically crosslinked thermosetting polymers, the most common such as vulcanized rubber, have excellent mechanical properties and heat resistance, but the existence of chemically crosslinked structures makes it difficult to carry out secondary processing, which makes a large number of Scraps and waste products generated during use are difficult to be reused and wasted through thermoplastic processing; thermoplastic elastomers have good thermoplasticity and are easy to process and recycle, but their thermo-mechanical properties are often not as good as chemical crosslinking Thermosetting polymers, thus limiting its application and scope to a certain extent

[0003] At this stage, some research has been devoted to the preparation of thermally reversible chemically crosslinked polymers, but due to the limitation of direct selection of commercialized polymers or the lack of its own molecular structure design, the final crosslinked polymers The main chain still contains a large number of unsaturated carbon-carbon double bonds, and the presence of unsaturated carbon-carbon double bonds makes the cross-linked polymer prone to produce a large number of irreversible cross-linked structures under thermal processing and long-term use of natural light.

Therefore, even if the polymer itself has a thermally reversible cross-linked structure, the irreversible cross-linked structure produced by unsaturated bonds in the later stage will inevitably greatly affect the recovery and secondary processing of the polymer.

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