PDMAA/Clay纳米复合水凝胶的制备与性能

以无机黏土为交联剂,采用偶氮二异丁腈(AIBN)为引发剂制备了新型的聚N,N ＇-二甲基丙烯酰胺/黏土(PDMAA/Clay)纳米复合水凝胶,作为对比,采用过硫酸钾(KPS)为引发剂制备了相对应的水凝胶.对两种纳米复合水凝胶的结构、形态、溶胀行为和力学性能等进行了研究.试验表明,黏土的结晶结构均已被破坏,黏土规整的片层被剥离并在凝胶中无序分布,起到交联剂的作用.随着黏土含量的增加,水凝胶的溶胀速率和溶胀度降低.采用AIBN制备的PDMAA/Clay水凝胶具有更好的韧性及更高的断裂强度,其断裂伸长率可达1 800％以上,而KPS制备的水凝胶的断裂伸长率在1 200％左右.

Preparation and Properties of PDMAA/Clay Nanocomposite Hydrogel

A new kind of nanocomposite hydrogel(PDMAA/Clay) based on N,N’-dimethylacrylamide(DMAA) crosslinked by inorganic clay was successfully prepared by using an initiator azo-bis-isobutyronitrile(AIBN).As a comparative experiment,another nanocomposite type hydrogel which employed the same monomer and crosslinking agent was synthesized by using an initiator potassium persulfate(KPS).The structure,morphology,swelling behavior and mechanical properties of these hydrogels were investigated.The results showed the regular crystal structures of clay were destroyed and the clay platelets were exfoliated and dispersed randomly in the hydrogels,which acted as a multifunctional crosslinker in the hydrogels.The swelling ratios and swelling rates of the PDMAA/Clay hydrogels decreased with increasing the clay content.Those hydrogels using AIBN had higher mechanical strength and larger elongation at break near to or greater than 1800%,compared with the hydrogels using KPS with elongation at break about 1200%.