Design,Synthesis,and Properties Of Polyester Materials Based On DDTH

In recent years,due to the increasing exploitation of petroleum resources by human beings,it has caused serious pollution to the environment.In order to cope with the depletion of petroleum resources,there is an urgent need to find some renewable resources for the preparation of polymers.In order to improve the competitiveness of thermoplastic polymers in applications,it is of great interest to find green,renewable monomers with good reactivity to impart new properties to materials.1、In this study,poly(decylene-terephthalate)(PDT)was modified with dimethyl 2,5-dihydroxyterephthalate(DDTH)as the third monomer.PDT has the defects of low melting point,slow degradation rate and small application range.In order to improve these problems,a series of modified copolyesters were prepared by melt polycondensation to maintain the original good crystallization ability and mechanical properties of the polymer.The melting point of the copolymers gradually increased with the increase of DDTH content up to 194.3 °C.The incorporation of DDTH gave the polymeric materials better thermal stability and also improved the degradability of the materials.In addition,the introduction of DDTH makes the material have certain antibacterial ability.2、In this study,to explore the effect of hydrogen bonding in N1,N4-bis(2-hydroxyethyl)-2,5-dimethoxyterephthalamide(BHDM)on the material properties,copolymers of BHDM with PDT and homopolymers of BHDM with different aliphatic chain dibasic acids were prepared by melt polycondensation.With the increase of BHDM incorporation,the Tg of PDT copolyester gradually increased and the mechanical strength of the material gradually increased.The thermal properties were characterized and analyzed,and the polymeric materials had good thermal stability.Tensile experiments on the homopolymers revealed that the mechanical strength gradually decreased and the toughness of the materials gradually increased with the growth of the dimeric acid chains,and the homopolymer materials had good resilience and self-healing ability,and the good properties of the materials were attributed to the influence of hydrogen bonding in the BHDM.Finally,we also investigated the UV shielding properties of the polymer,and the incorporation of BHDM monomer optimized the UV resistance of PDT and broadened its competitiveness in the field of UV resistance.