Insight on the striking influence of the chain architecture on promoting the exfoliation of clay in a polylactide matrix during the annealing process
Insight on the striking influence of the chain architecture on promoting the exfoliation of clay in a polylactide matrix during the annealing process
复制标题
DOI：
10.1039/c3sm52149d
复制
发表时间：
2013-10
期刊：
影响因子：
3.4
通讯作者：
Kun Yao;Xin Wen;Haiying Tan;J. Gong;Jun Zheng;Wei Zhao;Yang Wang;Dongmei Cui;H. Na;Tao Tang
中科院分区：
文献类型：
--
作者：
Kun Yao;Xin Wen;Haiying Tan;J. Gong;Jun Zheng;Wei Zhao;Yang Wang;Dongmei Cui;H. Na;Tao Tang
研究了聚乳酸（PLA）链的拓扑结构对PLA -有机改性粘土（OMC）纳米复合材料微观结构的影响。本文采用含羟基改性剂（I.34TCN）的OMC作为纳米填料。根据XRD和TEM的测量结果，在高温退火过程中，星形PLA （PLA3-x）与线性PLA （PLA1-1）的OMC分散态的变化完全不同。在退火过程中，简单的PLA3-x/OMC混合物中出现了从插层结构到剥离结构的转变，而PLA1-1/OMC体系中则保留了插层结构。星状PLA3-x的空间限制导致了层间膨胀，从而导致了OMC在PLA3-x基体中的剥离作用增强。结果表明，OMC层内的PLA3-x链浓度低于外部块体，因此，更多的PLA3-x链扩散到粘土层间，直到粘土层分离（剥落状态）。此外，星形PLA3-x/OMC复合材料中OMC的剥离程度强烈影响星形PLA3-x的玻璃化转变温度（Tg）。
The influence of the topological structure of polylactide (PLA) chains on the microstructure of PLA–organically modified clay (OMC) nanocomposites was studied. Here, an OMC with a hydroxyl group-containing modifier (I.34TCN) was used as the nanofiller. According to the results from the XRD and TEM measurements, the change in the dispersed states of the OMC with star-shaped PLA (PLA3-x) was totally different from that with linear PLA (PLA1-1) during annealing at high temperature. A transition from the intercalated to the exfoliated structure appeared in the simple PLA3-x/OMC mixture during the annealing process, but the intercalated structure was retained in the PLA1-1/OMC system. The enhanced exfoliation of the OMC in the PLA3-x matrix was attributed to the spatial limitation of the star-shaped PLA3-x, which made the intercalated interlayer swell. As a result, the concentration of PLA3-x chains within the layers of the OMC was lower than that of the outside bulk, and so, more PLA3-x chains diffused into the interlayers of the clay until the clay sheets separated (exfoliation state). Furthermore, the exfoliation extent of the OMC in the star-shaped PLA3-x/OMC composites strongly influenced the glass transition temperature (Tg) of star-shaped PLA3-x.