再生无色聚对苯二甲酸丁二醇酯-co-碳酸丁二醇酯流变性能研究

Study on Rheological Property of Colorless Regenerated Poly(Terephthalate-co-butylene Carbonate)Copolyster

有色废旧聚酯纺织品经乙二醇(EG)醇解后,与甲醇(MeOH)酯交换并脱色提纯,得到无色对苯二甲酸二甲酯(DMT);DMT再与1,4-丁二醇(BDO)酯交换得到无色对苯二甲酸双羟基丁二醇酯(BHBT);BHBT与碳酸二甲酯(DMC)和BDO酯交换,得到双甲基碳酸丁二醇酯(BMBC),通过缩聚反应制备出再生无色聚对苯二甲酸丁二醇酯-co-碳酸丁二酯(clr-PBCT)共聚酯。采用毛细管流变仪分别对clr-PBCT60和clr-PBCT70的熔融流变性能进行了测试。结果表明:2种clr-PBCT共聚酯的熔体呈现剪切变稀现象,具有非牛顿流体的流动特征;当剪切速率小于1100 s^(-1)时,clr-PBCT60的可纺性要优于clr-PBCT70;二者的非牛顿指数n均小于1,且随着测试温度的提高而增大;其粘流活化能(ΔE_(η))则随剪切速率的增加而减小,且clr-PBCT60共聚酯的ΔE_(η)明显低于clr-PBCT70;当剪切速率小于1100 s^(-1)时,clr-PBCT60样品熔体的结构黏度指数低于clr-PBCT70样品,剪切速率增大时则相反。

Colored post-consumer polyester textiles were first alcoholized by ethylene glycol(EG),and the alcoholysis were then transesterified with methanol(MeOH).The transesterification products were decolorized and purified to prepare colorless dimethyl terephthalate(DMT).It is then exchanged with 1,4-butanediol(BDO)to obtain colorless dihydroxybutanediol terephthalate(BHBT).And then,the regenerated colorless clr-PBCT copolyester was prepared by polycondensation of BHBT and dimethyl butylene carbonate(BMBC)which synthesized by transesterification of dimethyl carbonate(DMC)and 1,4-butanediol(BDO).The melting rheological properties of clr-PBCT60 and clr-PBCT 70 were tested by using capillary rheometer.The results show that,the melt of the two samples exhibited shear thinning phenomenon,exhibiting non Newtonian fluid flow characteristics;When the shear ratewas less than 1100 s^(-1),the spinnability of clr-PBCT60 was better than that of clr-PBCT70.The non-Newtonian exponents(n)of both samples were less than 1 and increased with the increase of testing temperature.Its viscous flow activation energy(ΔE_(η))decreased with the increase of shear rate,and the value of clr-PBCT60 were significantly lower than that of clr-PBCT70 sample.When the shear rate was less than 1100 s^(-1),the melt structural viscosity index of clr-PBCT60 was lower than that of clr-PBCT70,and the opposite was true when the shear rate increased.