Dynamic mechanical and dielectric relaxation characteristics of poly(trimethylene terephthalate)
Dynamic mechanical and dielectric relaxation characteristics of poly(trimethylene terephthalate)
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DOI：
10.1016/j.polymer.2006.08.005
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发表时间：
2006-09
期刊：
影响因子：
4.6
通讯作者：
Sumod Kalakkunnath;D. S. Kalika
中科院分区：
文献类型：
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作者：
Sumod Kalakkunnath;D. S. Kalika
研究了商用聚对苯二甲酸三甲基酯（PTT）在淬火和等温熔融结晶样品膜下的动态力学和介电弛豫性能。PTT的弛豫特性与其他低结晶度半柔性聚合物（如PET和PEEK）一致。虽然玻璃下弛豫在很大程度上不受晶体相存在的干扰，但通过玻璃转变的量热和宽带介电测量表明，由于晶体表面对晶体-非晶态间区的约束影响，熔融结晶PTT中存在相当大的刚性非晶相（RAP）分数。测得的介电弛豫强度（Δ /）随温度高于t而显著增加，表明RAP材料的逐渐动员，以及响应偶极子之间的相关性总体丧失。
The dynamic mechanical and dielectric relaxation properties of a commercial poly(trimethylene terephthalate) [PTT] have been investigated for both quenched and isothermally melt-crystallized specimen films. The relaxation characteristics of PTT were consistent with those of other low-crystallinity semiflexible polymers, e.g. PET and PEEK. While the sub-glass relaxation was largely unperturbed by the presence of the crystalline phase, both calorimetric and broadband dielectric measurements across the glass transition indicated the existence of a sizeable rigid amorphous phase (RAP) fraction in melt-crystallized PTT owing to the constraining influence of the crystal surfaces over the crystal–amorphous interphase region. A strong increase in measured dielectric relaxation intensity (Δɛ) with temperature above Tgindicated the progressive mobilization of the RAP material, as well as an overall loss of correlation amongst the responding dipoles.