Modification of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)by epoxy-based chain extenders

ADR series chain extenders were used for spinning poly(3-hydroxybutyrate-co-4-hydroxybutyrate)(P(3HB-co-4HB)).The rheology,thermal stability,crystallinity and fiber mechanical properties of P(3HB-co-4HB) and P(3HB-co-4HB) /ADR blends were investigated,along with the chain extendsion mechasim of ADR.The results showed that ADR can increase the melt strength,and improve the thermal stability of the fibers;and when the addition amount of ADR is 0.5% at 155 ℃,the melt has the maximum shearing strength and tensile strength,as well as optimum heat resistance.The influence of ADR on the crystal structure of P(3HB-co-4HB) is not remarkable,but it leads to the reduction of the crystallization rate and the increase of the maximum crystallization temperature.The mechanical properties of P(3HB-co-4HB) fibers are significantly improved with ADR added.