CuCl_2对聚乙二醇(PEG)构象和结晶行为的影响

用傅里叶变换红外光谱法(FT-IR)、差示扫描量热法(DSC)、广角X射线衍射法(WAXD)研究了少量过渡金属盐氯化铜(CuCl_2)对聚乙二醇(PEG)构象和结晶行为的影响.Cu~(2+)与PEG分子链中的氧原子有配位键生成,通过溶液电导率的测定,发现一个Cu~(2+)大约与3个PEG链节单元形成配位结构,从而使PEG的构象和结晶行为发生变化,随着体系中CuCl_2含量的增加,PEG分子链中OC-CO旁式构象相对反式构象含量逐渐增加,在CuCl_2含量(w)为7%左右时达到极大值,在CuCl_2含量(w)为9%时,反而是反式构象相对旁式构象含量多些.混合物中PEG的结晶度随着体系中CuCl_2含量的增加逐渐降低,含量(w)为9%时,又有所提高.

Effect of CuCl_2 on the Conformation and Crystallization Behavior of PEG

The effect of CuCl_2 on the conformation at changes and crystallization behavior Of PEG wasstudied by using FT-IR,DSC and WAXD.The CU~(2+) and the oxygen atoms of PEG molecular chain have formed coordination bond.By an electrical conductivity method it was found that one Cu~(2+) and three PEG chain units formed one coordination structure,which caused the change of conformation and crystallization behavior of PEG.With the increase of the content of CuCl_2 in the complexes,the amount of the gauche conformation relative to the trans conformation of PEG crystal increased.When the content of the CuCl_2 was about 7%(w),the gauche conformation reached maximum.When the content of the CuCl_2 was about 9%(w),the amount of the trans conformation relative to the gauche conformation of PEG crystal increased.With the increase of the content of CuCl_2.the crystallinity of PEG in the complexes decreased.When the content of CuCl_2 was about 9%(w),the crystallinity increased again.