Formation of crystalline inclusion compounds of poly (vinyl chloride) of different stereoregularity with γ-cyclodextrin
Formation of crystalline inclusion compounds of poly (vinyl chloride) of different stereoregularity with γ-cyclodextrin
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DOI：
10.1002/pola.22014
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发表时间：
2007-06-15
影响因子：
--
通讯作者：
Balik, C. Maurice
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文献类型：
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作者：
Martinez, Gerardo;Gomez, Marian A.;Balik, C. Maurice
本文报道了两种不同等规含量的聚氯乙烯样品形成的环糊精（γ - cd）包合物（ICs）的形成和详细表征。采用x射线衍射、固态c -13核磁共振、溶液h -1核磁共振、傅里叶红外、差示扫描量热法和热重分析对lc进行了表征。实验证明了客体聚合物链被包含在由- cd晶体主晶格形成的狭窄通道中。对去除宿主γ - cd后获得的聚结聚氯乙烯（PVC）的检测显示，具有较高等规含量的聚结PVC样品具有不同的特征。DSC观察到该PVC的Tg升高。相反，等规含量较低的聚结PVC样品的T-g与合成样品的T-g几乎相同。热重分析表明，具有较高等规含量的聚结聚氯乙烯通过穿入并从其γ - cd集成电路中提取改性后获得了一定程度的稳定性。结果表明，当聚氯乙烯与T-CD等固体主体晶格形成集成电路时，发生了不可逆的构象变化。PVC分子在IC中扩展并重组成更稳定的构象，从而改善了聚结样品的性能。(C) 2007 Wiley期刊公司
This work reports the formation and detailed characterization of the ycyclodextrin (gamma-CD) inclusion compounds (ICs) formed with two poly (vinyl chloride) samples with different isotactic content. The lCs were characterized by X-ray diffraction, solid state C-13-NMR, solution H-1-NMR, FT-infrared, differential scanning calorimetry, and thermogravimetric analysis. Experimental evidence of the inclusion of the guest polymer chains into the narrow channels created by the gamma-CD crystalline host lattice has been obtained. Examination of coalesced poly (vinyl chlorides) (PvCs) obtained after the host gamma-CD is removed reveals different characteristics specifically for the coalesced PVC sample with higher isotactic content. Am increase in Tg was observed by DSC for this PVC. To the contrary, the T-g of the coalesced PVC sample with lower isotactic content is almost the same as that of the as-synthesized sample. Thermogravimetric analysis indicated that coalesced PVC with higher isotactic content acquires a degree of stabilization after modification by threading into and being extracted from its gamma-CD IC. The results suggest that an irreversible conformational change takes place when PVC forms ICs with a solid host lattice like T-CD. The PVC molecules extend and reorganize into a more stable conformation in the IC, consequently improving the properties of the coalesced sample. (C) 2007 Wiley Periodicals, Inc.