Study On Binary Chloride Chain Extender Synthesis And Biological Degradation Of PBs And P (Bs-co-1,2-PS)

Poly(butylene succinate)(PBS), because of outstandingbiodegradability, have been affected by global researcher attention.Being melting point, good processing properties, while introducingmethyl(group) into the main chain could made modification and becamemolecular asymmetry in the main chain, thus poly(butylenesuccinate-co-succinate1,2-propylene glycol) got a better tensileproperties and biodegradability than PBS did. However, thoughconventional synthetic methods were difficult to obtain a highermolecular, either melt polycondensation, solution polycondensation ormelt and solution phase polycondensation, which largely limited theprocessing and application performance of PBS and P(BS-co-1,2-PS).In this thesis, hexene diacyl chloride (HDC) and Succinic chloride(SUC) were used as chain extender to synthesis the high molecular ofPBS and P(BS-co-1,2-PS).(1) Hexene diacyl chloride (HDC) was used as chain extender tosynthesis PBS instead of the conventional synthetic method. Theoptimal reaction conditions of the extended chain reaction were studied;molecular weight, melting point and mechanical properties and so onwere tested at the same time. The results were showed as following.①The optimum reaction conditions of the extended chain reaction wasthat the addition of hexene diacyl chloride (HDC) was3%, reactiontemperature was140℃, reaction time was50minutes.②Molecular weight of PBS expanded from5.79×104to10.14×104.③Melting pointof PBS reached to141℃, which increasing25℃.④The elongation ofPBS was changed from129%before to259%.⑤Thermaldecomposition temperature of PBS was increased to343℃.(2) Based on the best reaction conditions, with the hexene diacylchloride (HDC) as chain extender to synthesis P(BS-co-1,2-PS) andits series of copolymers. The molecuⅢlar weight, melting point and otherproperties of P(BS-co-1,2-PS) and copolymers were detected beforeand after chain extension. The results showed that:①The best ratiobetween hexene diacyl chloride (HDC) and P (BS-co-1,2-PS) and itscopolymers was20%;②The molecular weight of P(BS-co-1,2-PS) andits copolymers increased from5.33×104to10.52×104.③Melting pointof P(BS-co-1,2-PS) and its copolymers was up to121℃.(3)Based on the optimum conditions of our laboratory to synthesisP(BS-co-1,2-PS) and its copolymers with succinic chloride (SUC)used as chain extender. Molecular weight, melting point and thermaldecomposition temperature of polymers were tested. The results wereshowed as following.①Under the optimum conditions, the best ratiobetween succinic chloride (SUC) and P(BS-co-1,2-PS) and itscopolymers was20%.②Melting point of P(BS-co-1,2-PS) and itscopolymers was reached to122℃,③The molecular weight ofP(BS-co-1,2-PS) and its copolymers increased from5.33×104to10.33×104.④Thermal decomposition temperature of P(BS-co-1,2-PS)and its copolymers reached up to350℃.(4)Biodegradability of PBS and P(BS-co-1,2-PS) and itscopolymers were tested in the degradation nutrient solution, conclusionwere obtained through the weight loss:①Without chain extender, thedegradation rate of copolymers of PBS (PBSPS-15and PBSPS-20)which were greater than PBS, and PBSPS-20had the maximum weightloss rate.②With hexene diacyl chloride (HDC) and Succinic chloride(SUC) chain extender, the degradation rate of copolymers of PBS(PBSPS-15and PBSPS-20) which were greater than PBS was. Thedegradation rate ordered: PBSPS-20﹥PBSPS-15﹥PBS﹥HDC -PBSPS-20﹥SUC-PBSPS-20﹥HDC-PBS﹥SUC-PBS.