聚二羟基甲基硅氧烷改性聚醚酯弹性体的合成与表征

Synthesis and Characteristics of Multiblock Terpoly(Ester-Ether-Siloxane) Elastomers

以对苯二甲酸二甲酯(DMT)、1,4丁二醇(BD)、聚乙二醇(PEG)和聚二羟基甲基硅氧烷(PDMS)为原料,采用熔融缩聚法一步合成了聚硅醚酯弹性体(PBT-co-PEG/PDMS)。通过红外光谱、核磁共振和凝胶色谱等分析方法对其分子结构和分子量进行了表征,用差示扫描量热(DSC)和热重分析(TG)研究了耐热性能,结果发现,PEG和PDMS参与了共聚反应,随着聚合物中聚二羟基甲基硅氧烷含量的增加,聚合物的数均分子量相应减小,PDMS含量为10%的共聚物数均分子量仅为3万;热分析结果表明,随着PDMS含量的增加,聚合物的熔点从175℃逐渐升高到200℃,同时起始降解温度也逐步提高。

Terpoly（ester-ether-siloxane）（PBT-co-PEG/PDMS） was prepared by melt poly-condensation with dimethyl terephthalate（DMT）,l,4-butandiol（BD）,polyethylene glycol（PEG） and poly dihydroxy methyl siloxane（PDMS）.The chemical structure and molecular weight of the polymers were presented by Fourier transform infrared spectra（FT-IR）,1H nuclear magnetic resonance spectrum（1H-NMR） and gel permeation in chromatography（GPC）,the thermal properties were measured by differential scanning calorimetry（DSC） and thermogravimetry（TG）.The results show that the number average molecular weight of polymerization products decreases with the increasing content of PDMS.The GPC shows that the number average molecular weight only is 30 thousand when the content of PDMS is 10%;and the melt point rises from 175 ℃ to 200 ℃ with the increasing of PDMS,moreover,the increasing of the mass of PDMS results in higher decomposition temperature.