The effect of structure evolution upon heat treatment on the beta-nucleating ability of calcium pimelate in isotactic polypropylene
The effect of structure evolution upon heat treatment on the beta-nucleating ability of calcium pimelate in isotactic polypropylene
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热处理时结构演变对等规聚丙烯庚二酸钙β成核能力的影响
DOI：
10.1016/j.polymer.2018.06.060
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发表时间：
2018-08
期刊：
影响因子：
4.6
通讯作者：
Feng Jiachun
中科院分区：
文献类型：
--
作者：
Yue Yang;Hu Dingding;Zhang Qinglong;Lin Jinyou;Feng Jiachun
庚二酸钙（CaPim）是等规聚丙烯（iPP）最稳定、最有效的β-成核剂之一。为了建立CaPim的结构-性能关系，研究了合成后原样的CaPim和在130至330 °C的温度（Ta）下退火的CaPim的结构和相应的β-成核能力。结果表明，CaPim和CaPim在较低的Ta下退火后均为结晶水合物。然而，当在约180 °C下处理时，高度有序的晶体结构将不可逆地被破坏并转化为弱有序形式，伴随着结晶水的完全剥夺。在180-290 °C的Tarange下，弱有序CaPim仍保持较高的有序度，但Taleads进一步增加，CaPim转化为无序无定形形式。对含有0.05wt%各种退火CaPim的iPP样品的相对β-形式含量（kβ）的测量表明，β-成核选择性与CaPim的有序程度密切相关。如所预期的，结晶CaPim可以诱导0.82-0.91的高kβ值。有趣的是，具有残余有序结构的弱有序CaPim仍然显示出相当高的β-选择性，kβ值为0.53-0.68，而无定形CaPim几乎失去了其β-成核能力。结合外延结晶理论，提出了CaPim结构与β-成核选择性相关的可能机制。
Calcium pimelate (CaPim) is known as one of the most stable and effectiveβ-nucleating agents for isotactic polypropylene (iPP). To establish the structure-properties relationships of CaPim, the structure and correspondingβ-nucleating ability of as-synthesized CaPim and CaPim annealed at temperature (Ta) varying from 130 to 330 °C were investigated. Our results revealed that as-synthesized CaPim and CaPim annealed at a relatively lower Tawere crystalline hydrates. However, the highly ordered crystalline structure would irreversibly destroyed and transformed to a weakly ordered form when treated at about 180 °C, accompanied by the complete deprivation of crystal water. The weakly ordered CaPim still maintained relatively high ordered degree at Tarange of 180–290 °C, but a further increase of Taleads to the conversion of CaPim to disordered amorphous form. The measurements of relativeβ-form content (kβ) of iPP samples containing 0.05 wt% of various annealed CaPim suggested that theβ-nucleating selectivity was closely correlated to the ordered degree of CaPim. As expected, the crystalline CaPim could induce high kβvalues of 0.82–0.91. Interestingly, the weakly ordered CaPim with residual ordered structure still showed a rather highβ-selectivity with kβvalues of 0.53–0.68, while the amorphous CaPim almost lost itsβ-nucleating ability. Combined with the epitaxial crystallization theory, a probable mechanism on the correlation between structure andβ-nucleating selectivity of CaPim was proposed.
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影响因子：
4.6
作者：
Benedikt R. Neugirg;N. Helfricht;Steffen Czich;H. Schmidt;G. Papastavrou;A. Fery
通讯作者：
Benedikt R. Neugirg;N. Helfricht;Steffen Czich;H. Schmidt;G. Papastavrou;A. Fery
含有不同成核能力的山梨醇基成核剂的等规聚丙烯中剪切诱导结晶前驱体的松弛行为
影响因子：
3.3
作者：
Fan Jiashu;Zhang Qinglong;Hu Dingding;Ren Qilin;Feng Jiachun
通讯作者：
Feng Jiachun
影响因子：
2.5
作者：
A. Turner Jones;Jean M. Aizlewood;D. R. Beckett
通讯作者：
A. Turner Jones;Jean M. Aizlewood;D. R. Beckett
DOI：
10.1002/pol.1983.180211207
发表时间：
1983-12
期刊：
Journal of Polymer Science Part B
影响因子：
--
作者：
J. Wittmann;A. Hodge;B. Lotz
通讯作者：
J. Wittmann;A. Hodge;B. Lotz
DOI：
--
发表时间：
2002-06
期刊：
Guang pu xue yu guang pu fen xi = Guang pu
影响因子：
--
作者：
Xiao-jun Li;Ke-liang Hu;Yun-lan Huang;Guilin Zhou
通讯作者：
Xiao-jun Li;Ke-liang Hu;Yun-lan Huang;Guilin Zhou