聚乙二醇/聚对苯二甲酸丁二醇酯聚醚酯弹性体的合成与表征——不同硬段长度对材料性能的影响

以熔融缩聚法合成了一系列基于聚乙二醇 (PEG) 聚对苯二甲酸丁二醇酯 (PBT)的聚醚酯热塑性弹性体 ,用NMR、IR、DSC及力学性能测试等方法表征了材料的结构及性能 .讨论了在相同软段长度情况下 ,不同硬段长度对材料结构与性能的影响 .实验表明 ,随着体系中硬段PBT长度的减小 ,弹性模量、抗拉强度降低 ,特性粘度、吸水量及断裂形变量增加 ,材料性能良好可调

SYNTHESIS AND CHARACTERIZATION OF POLYETHER ESTERS ELASTOMERBASED ON POLYETHYLENE GLYCOL AND POLY(BUTYLENE TEREPHTHALATE)--INFLUENCE OF DIFFERENT HARD SEGMENT LENGTH ON POLYMER PROPERTIES

A series of polyether esters thermoplastic elastomer,based on polyethylene glycol (PEG) as the soft segment and poly(butylene terephthalate)(PBT) as the hard segment,are synthesized by molten polycondensation and characterized by means of NMR,IR,DSC and mechanical testing.The influence of hard segment lengths on the properties of the copolymer is investigated in the case of the soft segment length remaining constant.It is observed that,first,the length of hard segments calculated from +1H NMR spectra is increased with the decrease of PEG content; secondly,four phases corresponding to the amorphous and the crystal phases of soft and hard segments coexist at certain temperatures; thirdly,the glass transition temperature ( T g) of the soft segment is increased,at the same time its molten point ( T m) and the degree of crystal ( W c) are decreased with the increase of the PBT segment length.Moreover,the inherent viscosity changes from 1 34 dL/g to 1 72 dL/g,and water uptake increases from 29 4% to 104 4% as the PEG content changes from 30% to 80%(wt).Although all copolymers are distinguished by a high elastic and plastic deformation and break at very high relative deformations,the sample of high PEG content displays the typical high elastic state,while the sample of low PEG centent exhibits neck formation characteristics in the stress strain curve.Obviously,the material's properties under constant soft segment length can be tailored conveniently by changing the weight ratio of two components in formula.