水凝胶-水凝胶复合材料的制备与表征

将聚乙二醇400(PEG400)溶胀的交联N-乙烯吡咯烷酮(NVP)水凝胶微粒浸渍在含有引发剂过氧化苯甲酰(BPO)的甲基丙烯酸-2-羟基乙酯(HEMA)单体中并加热引发聚合反应,制备水凝胶-水凝胶复合材料,研究了产物的溶胀行为,并采用SEM、DSC对产物进行了表征。结果表明,水凝胶-水凝胶复合材料的饱和含水量随交联NVP水凝胶颗粒的含量及饱和含水量增大而增大,两种水凝胶之间的界面结构可分为包埋、部分互穿网络以及完全部分互穿网络等三种,其原因在于HEMA单体部分进入交联NVP水凝胶微粒并进行原位聚合的程度不同;处于分散相的水凝胶与处于连续相的水凝胶的吸水倍率不同,导致水凝胶-水凝胶复合材料吸水溶胀时不同相结构之间互相制约,处于分散相的水凝胶的大分子链不能充分伸展,非冻结水的熔融峰被自由水的熔融峰掩盖,表现为DSC谱图上非冻结水的熔融峰被自由水的熔融峰掩盖。

Synthesis and characterization of hydrogel-hydrogel composite.

Hydrogel-hydrogel composite was synthesized by polymerization of hydroxyethylmethacrylate(HEMA) which contains initiator BPO and particles of crosslinked N-vinylpyrrolidone(NVP) swollen by PEG-400,the swelling behavior was studied,and the hydrogel-hydrogel composite was characterized by SEM and DSC.The results showed EWC of the hydrogel-hydrogel composite increased when the dosage and EWC of the particles of crosslinked NVP increasing;the interficial structure of the hydrogel-hydrogel composite can be divided into three types of no interpenetrating interface,partly interpenetrating interface and fully interpenetrating interface.The difference of the swelling properties between the two different hydrogel leading to macromolecular chain of the hydrogel that in dispersed state couldn't spread adequately,resulted in the content of non-freezing water in the hydrogel-hydrogel composite was less than common hydrogel,the thawing peak of non-freezing water was covered by that of free water on the DSC pattern;formation of water in different state in the hydrogel was a dynamic process,and was related to the swelling behavior of the hydrogel,the formation of non-freezing water and free water needed adequate space.