Crystallization of polycaprolactone with reduced entanglement
Crystallization of polycaprolactone with reduced entanglement
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减少缠结的聚己内酯结晶
DOI：
10.1016/j.eurpolymj.2018.03.017
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发表时间：
2018-05
影响因子：
6
通讯作者：
Kong Jie
中科院分区：
文献类型：
--
作者：
Tian Nan;Liu Dong;Wei Hanghang;Liu Yanping;Kong Jie
研究了聚己内酯（PCL）在宽浓度范围内结晶的结构，探讨了纠缠量与结晶结构之间的关系。采用优良溶剂氯仿与非溶剂乙醇组成的混合溶剂控制结晶起始浓度（浓度、质量分数），其变化范围为0.13 ~ 0.53。采用静电纺丝法和熔融结晶法实现了高密度结晶。溶液中聚合物的体积分数与缠结数(N)的关系为：lawN/N0=ϕ1.3；在这项工作中，将尺度定律修改为asN/N0≈conset1.3作为近似值。通过小角x射线散射（SAXS）和差示扫描量热法（DSC）获得了非晶态区厚度（la）和熔合焓（ΔH）。结果表明，随着conset1.3的增加，从4.5 nm单调增加到10.2 nm， andΔH单调减少，从92 J/g单调减少到50 J/g。随着conset1.3的平滑变化oflaandΔH表明，纠缠度的增加导致非晶态区域变厚，结晶度降低，即使纠缠数低至熔体的十分之一时也是如此。此外，还讨论了薄片厚度（lc）的变化。
Structure of polycaprolactone (PCL) crystallized in a wide concentration range was investigated to correlate entanglement content with the formed structure. Mixed solvent constituted by good solvent chloroform and nonslovent ethanol was used to control the concentration crystallization started (conset, weight fraction), which varied from 0.13 to 0.53. Crystallization at higherconsetwas achieved by electrospinning and melt crystallization. The concentration correlates with entanglement number (N) by the scaling lawN/N0=ϕ1.3withϕthe volume fraction of polymer in solution. In this work, the scaling law was modified asN/N0≈conset1.3as an approximation. Thickness of amorphous region (la) and fusion enthalpy (ΔH) were obtained through small angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC). It is found thatlaincreases monotonically withconset1.3from 4.5 nm to 10.2 nm, andΔH decreases monotonically from 92 J/g to 50 J/g. The smooth change oflaandΔH withconset1.3indicates increased entanglement leads to thicker amorphous region and lower crystallinity, which is valid even when the entanglement number is as low as one-tenth of that in melt. Moreover, changes in lamellae thickness (lc) is also discussed.
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影响因子：
2.3
作者：
Yangyang Wang;Shi‐Qing Wang
通讯作者：
Yangyang Wang;Shi‐Qing Wang
影响因子：
5.5
作者：
S. Milner
通讯作者：
S. Milner
影响因子：
5.5
作者：
Huang, Qian;Mednova, Olga;Hassager, Ole
通讯作者：
Hassager, Ole
影响因子：
4.6
作者：
Nan Tian;Dong Liu;Yanping Liu;Lingpu Meng;Xiangyang Li;Jie He;Liangbin Li;Xiuhong Li;Feng Tian
通讯作者：
Feng Tian
DOI：
10.1002/polb.24051
发表时间：
2016-08
期刊：
Journal of Polymer Science Part B
影响因子：
--
作者：
Xiangyang Li;Yanping Liu;Xingyou Tian;Kunpeng Cui
通讯作者：
Xiangyang Li;Yanping Liu;Xingyou Tian;Kunpeng Cui