Enhancing the Crystallization Performance of Poly(L-lactide) by Intramolecular Hybridizing with Tunable Self-assembly-type Oxalamide Segments
Enhancing the Crystallization Performance of Poly(L-lactide) by Intramolecular Hybridizing with Tunable Self-assembly-type Oxalamide Segments
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DOI：
10.1007/s10118-020-2461-3
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发表时间：
2020-08
影响因子：
4.3
通讯作者：
Manman Yu;Weijun Yang;Deyu Niu;Xiaoxia Cai;Yunxuan Weng;W. Dong;Mingqing Chen;Pengwu Xu;Yang Wang;H. Chu;Pingming Ma
中科院分区：
文献类型：
--
作者：
Manman Yu;Weijun Yang;Deyu Niu;Xiaoxia Cai;Yunxuan Weng;W. Dong;Mingqing Chen;Pengwu Xu;Yang Wang;H. Chu;Pingming Ma
本论文合成了端羟基双（2-羟乙基）丙二酰胺（OXA 1）和双（2-羟乙基）丙二酰胺（OXA 2），以引发L-丙交酯开环聚合制备了丙二酰胺杂化聚（L-丙交酯）（PLAOXA），PLAOXA 1和PLAOXA 2。聚乳酸的结晶性能是通过聚乳酸氧烷酰胺链段的自组装作为初始异相核而得到改善的。用Hoffman-Lauritzen理论研究了PLAOXA 1和PLAOXA 2的晶体生长动力学，发现PLAOXA 1和PLAOXA 2的成核能垒低于PLA。因此，PLAOXA的结晶速度比PLA快得多，球晶尺寸和半衰期结晶时间分别减少了74.8%和86.5%（T = 125 °C）。此外，在10 °C/min的降温速率下，PLAOXA 1和PLAOXA 2的结晶度分别是纯PLA的6倍和8倍。结果表明，PLA主链中的酰胺链段的杂化将起到自异核作用，从而促进结晶速率。PLAOXA 2与PLAOXA 1相比，其酰胺链段含量越高，促进作用越强。因此，本研究可能提供一种通过杂化大分子结构促进半结晶高分子材料结晶的通用方法。
In this work, hydroxyl-terminated oxalamide compoundsN1,N2-bis(2-hydroxyethyl)oxalamide (OXA1) andN1,N1′-(ethane-1,2-diyl)bis(N2-(2-hydroxyethyl)oxalamide (OXA2) were synthesized to initiate the ring-opening polymerization of L-lactide for preparation of oxalamide-hybridized poly(L-lactide) (PLAOXA),i.e., PLAOXA1and PLAOXA2. The crystallization properties of PLA were improved by the self-assembly of the oxalamide segments in PLAOXAwhich served as the initial heterogeneous nuclei. The crystal growth kinetics was studied by Hoffman-Lauritzen theory and it revealed that the nucleation energy barrier of PLAOXA1and PLAOXA2was lower than that of PLA. Consequently, PLAOXAcould crystallize much faster than PLA, accompanied with a decrease in spherulite size and half-life crystallization time by 74.8% and 86.5% (T = 125 °C), respectively. In addition, the final crystallinity of PLAOXA1and PLAOXA2was 6 and 8 times higher, respectively, in comparison with that of neat PLA under a controlled cooling rate of 10 °C/min. The results demonstrate that the hybridization of oxalamide segments in PLA backbone will serve as the self-heteronucleation for promoting the crystallization rate. The higher the content of oxalamide segments (PLAOXA2compared with PLAOXA1) is, the stronger the promotion effect will be. Therefore, this study may provide a universal approach by hybridizing macromolecular structure to facilitate the crystallization of semi-crystalline polymer materials.