聚丙烯酰胺凝胶的合成及性能

在无交联剂的情况下,丙烯酰胺(AM)与含辣素功能团结构的单体N-(4-羟基-3-甲氧基-苄基)-丙烯酰胺(HMBA)或N-6-丙烯酰胺甲基-1,3-苯并二氧杂戊环-5-甲基]丙烯酰胺(AMBMA)在水溶液中发生自由基共聚反应,合成聚丙烯酰胺凝胶,并通过红外光谱对凝胶的结构进行表征。实验结果表明,在溶剂量180mL、引发剂K2S2O8用量0.5g、HMBA用量0.010mol、70℃的条件下,当AM与HMBA的摩尔比大于等于13.5时,可以形成凝胶;由于HMBA及AMBMA单体中的刚性苯环结构,使AM-HMBA和AM-AMBMA凝胶具有较快的吸水速率,5h内平衡溶胀度分别达643.2%和405.0%,高于无苯环结构的AM-N-羟甲基丙烯酰胺凝胶;在60℃下,AM-HMBA和AM-AMBMA凝胶5h的保水率分别为39.2%,41.3%,而AM-N-羟甲基丙烯酰胺凝胶仅为10.8%。

Synthesis and Properties of Polyacrylamide Gel

Without using cross-linking agent,two types of polyacrylamide gel were synthesized from acrylamide(AM)with relevant monomers via radical copolymerization in aqueous solution.The monomers should contain derivant of capsaicin,such as N-(4-hydroxy-3-methoxy-benzyl)-acrylamide(HMBA)or N-6-(acryloylamino-methyl)-benzo(1,3)dioxo-5-methyl]-acrylamide(AMBMA).The obtained gels,AM-HMBA and AM-AMBMA,were identified by IR.Using 180 mL solvent and 0.5 g K2S2O8 as initiator,AM-HMBA gel can be synthesized at 70 ℃ when n(AM) ∶n(HMBA)is equal to or higher than 13.5.AM-HMBA and AM-AMBMA gels have better water absorbing rates and water retention because of rigidity of benzenoid structure in HMBA and AMBMA.The equilibrium swelling degrees of AM-HMBA and AM-AMBMA gels are 643.2% and 405.0% respectively in 5 h,which are higher than that of conventional AM-N-hydroxymethyl acrylamide gel.The water retentions of AM-HMBA and AM-AMBMA gels at 60 ℃ in 5 h are 39.2% and 41.3% respectively,and that of AM-N-hydroxymethyl acrylamide gel is only 10.8%.