摘要
从弛豫理论出发，在不同的时效时间和不同降温速率下对非晶聚合物PVC玻璃化转变过程中与时间参量密切相关的。α峰峰温（Tα）和用热膨胀法标定的玻璃化转变温度（Tg）进行了对比测量，得出α内耗峰是非晶态聚合物热平衡态下的特征内耗峰，其弛豫机制是在热平衡态下独立存在的Tg是热平衡态到非平衡态的转变温度点，两者都与非晶态结构的存在紧密相关，它们的表观行为取决于非晶聚合物热平衡态下的同一个本征弛豫时间。
A systematic study on the effect of physical aging and cooling rate to α-relaxation peak are carried out in PVC. It was said that α-peak and Tg are not the same concept. Both are close connected with amorphous polymer state, but different behaviors were pronounced in the same pretreatment conditions: varying physical ageing time in Sub-Tg or changing cooling rate from Tg+20K to room temperature. Some interesting results were obtained as follows: when Ti lower with increase of ageing time or decreasing of cooling rate, α-peak temperature keeps constant. In other hand, the intensity of the u-Peak decreases. This behavior shows that α-relaxation peak is not a typical relaxational internal friction peak, as there is a quenching peak added on it. Under the pretreatment condition, α-peak data of the amorphous polymer can gives out more derailed and exact ioformations than small-strain creep curves.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
1997年第1期52-56,共5页
Chinese Journal of Materials Research
关键词
玻璃化转变
内耗
弛豫
非晶
聚合物
glass transition internal friction relaxation amorphous polymers
