Thermodynamic investigation on melting and recrystallization of poly(dimethylsiloxane) rubbers under strain
Thermodynamic investigation on melting and recrystallization of poly(dimethylsiloxane) rubbers under strain
复制标题
聚二甲基硅氧烷橡胶在应变下熔融和再结晶的热力学研究
DOI：
10.1016/j.polymer.2022.125105
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发表时间：
2022
期刊：
影响因子：
4.6
通讯作者：
Suzuki Hal
中科院分区：
文献类型：
--
作者：
Umeda Miyu;Wakabayashi Tomonari;Kamiyama Tadashi;Suzuki Hal
为了研究拉伸状态下聚二甲基硅氧烷橡胶的熔融和结晶性能，用绝热量热法测定了拉伸聚二甲基硅氧烷橡胶在78~300K温度范围内的热容。拉伸至伸长率为2.56时，熔融温度T_(Fus)提高4K，熔融热容量峰变宽，熔融Δ熔融热焓增加3.6%。ΔfusH的增加是由于橡胶和晶态的内能都发生了变化。Tfus的增加与内能的变化和橡胶态构象熵的降低有关。熔融峰的加宽表明晶体尺寸分布较宽。对不同温度下再结晶样品的测量表明，随着拉伸倍数的增加，晶体增厚率和再结晶动力学速率增大。
In order to clarify the melting and crystallization properties of poly(dimethylsiloxane) (PDMS) rubbers under strain, heat capacity measurements were conducted for stretched PDMS rubbers by adiabatic calorimetry in the temperature range 78–300 K. Upon stretching to the elongation ratio of 2.56, the fusion temperatureTfusincreased by 4 K, the fusion peak in heat capacity broadened, and the enthalpy of fusion ΔfusHincreased by 3.6%. The increase in ΔfusHwas due to the change of internal energy both in the rubbery and crystalline state. The increase inTfuswas related to these changes in internal energy and the decrease in conformational entropy in the rubbery state. Broadening of the fusion peak indicated the wider distribution of crystal size. The measurements of the samples recrystallized at different temperatures revealed that the crystal thickening ratio and recrystallization kinetic rate increased with stretching ratios.