热塑性可生物降解PBSeT共聚酯的合成及性能研究

Synthesis and Properties of Thermoplastic Biodegradable PBSeT Copolyesters

以癸二酸(SeA)、对苯二甲酸(TPA)和丁二醇(BDO)为单体,采用先酯化后缩聚的两步法合成了聚(癸二酸丁二醇-对苯二甲酸丁二醇)共聚酯(PBSeT)。研究SeA与TPA摩尔比(100∶0、90∶10、70∶30、50∶50、30∶70、10∶90)的变化对共聚酯结构、热性能、力学性能和降解性能的影响。结果表明,所合成聚酯的重均相对分子质量(M_w)在178 300～214 277 g/mol范围内;随着刚性单体TPA含量的增加,共聚酯的熔融温度(T_m)、结晶温度(T_c)呈现出先降低后升高的趋势,其中PBSeT(50∶50)结晶能力最弱;当TPA含量由10%(摩尔分数,下同)增加至90%时,共聚酯的玻璃化转变温度(T_g)逐渐增加;共聚酯具有较为接近的热稳定性;当共聚酯刚性单体TPA含量较高时,共聚酯呈现较高的拉伸强度,其中PBSeT(30∶70)的拉伸强度最大,为53.0 MPa;PBSeT(50∶50)的断裂伸长率最大,达到1 040%;黑曲霉菌降解实验表明,随着TPA单体含量的增加,共聚酯的降解能力大致呈降低的趋势。

Poly(butylene sebacate-co-terephthalate)(PBSeT) copolyester were synthesized from terephthalic acid(TPA), sebacic acid(SeA) and butylene glycol(BDO) through a two-step process of esterification and polycondesation. The effects of molar ratio of SeA to TPA(100∶0, 90∶10, 70∶30, 50∶50, 30∶70 and 10∶90) on the structures, thermal, mechanical and degradation properties of copolyesters were studied. The weight average molecular weight(M_w) of polyesters was in the range of 178 300 to 214 277 g/mol. With the increase of the content of rigid monomer TPA, the T_m and T_c of the copolyesters first decreased and then increased. Among them, the crystallization capacity of PBSeT(50∶50) was the weakest. When the TPA content increased from 10 mol % to 90 mol %, the T_g of the copolyesters gradually increased. The thermal stabilities of copolyesters were relatively close. When the content of TPA was higher, the copolyester exhibited higher tensile strength. Among them, the tensile strength of PBSeT(30∶70) was the highest, which was 53.0 MPa, and the elongation at break of PBSeT(50∶50) was the highest, reaching 1 040 %. The degradation experiment of Aspergillus niger showed that the degradation ability of copolyester decreased with the increase of TPA monomer content.