扩链剂联用对PETG扩链反应与流变性能的影响

Effect of Combining Different Chain Extender Agents on the Chain Extending Reaction and Rheological Behavior of PETG

通过扩链反应对聚对苯二甲酸乙二醇-1,4-环己烷二甲醇酯(PETG)进行改性以提高PETG的熔体强度和黏度。采用熔体流动速率仪、旋转流变仪及转矩流变仪考查了扩链剂的使用方式对PETG结构及流变性能的影响。结果表明,酸酐类和环氧类多官能团单体联用对PETG的扩链效果最好,PETG的熔体流动速率由12.83 g/10 min降低至7.50 g/10 min,零剪切黏度(η_0)由2022.8 Pa·s增加到4764.2 Pa·s,特征松弛时间(τ_0)由0.78 s增加到3.58 s;改性后PETG仍保持着线形结构而未形成凝胶。

In this paper, chain extenders were added to poly （ethylene terephthalateco-1, 4- cylclohexylenedimethylene terephthalate）（PETG） to improve its melt strength and viscosity through reactive processing. Effect of chain extenders on structure and rheological behavior of PETG was studied by fusion index instrument, rotational rheometer, and torque rheomoeter. It was revealed that, the simultaneous addition of pyromellitic dianhydride （PMDA） and triglycidylisocyanurate（TGIC） to PETG led to higher melt strength and viscosity. In this case, the melt flow index of the extended PETG decreased from 12. 83 to 7. 50 g/10 min. While the zero- shearing viscosity （η0） increased from 2020 to 4760 Pa .s and the characteristic relaxationtime （τ0） increased from 0. 78 to 3.58 s. Moreover, the extended PETG remained a linear structure and no gel was formed.