新型共聚水凝胶P(HEMA-co-EMA)交联网络的结构参数

STUDIES ON NETWORK PARAMETERS OF NOVEL P(HEMA-co-EMA) COPOLYMERIC HYDROGELS

以大分子单体甲基丙烯酸环氧酯(EM A)与亲水性单体甲基丙烯酸-β-羟乙酯(HEM A)为原料,双甲基丙烯酸乙二醇酯(EDM A)为交联剂,采用本体聚合方法合成了一系列新型水凝胶。从宏观方面研究了EM A含量、温度对水凝胶溶胀、拉伸性能的影响,进而研究了水凝胶的交联网络结构参数。EM A含量的增大加强了水凝胶内部疏水基团间的相互作用,使平衡含水EW C降低,聚合物体积分数2φ增大,拉伸强度、杨氏模量、有效交联密度eυ以及聚合物-水相互作用参数χ也随之增大,网链分子量Mc减小。当温度由275 K升至304 K,水凝胶样品EM A 25/HEM A 75的EW C值下降,2φ值和χ值增大。

A series of hydrogels based on maeromonomer epoxy methyaerylate （EMA） and hydrophilic 2-hydroxyethyl methacrylate （HEMA） crosslinked with ethylene dimethacrylate （EDMA） were synthesized by bulk copolymerization. The effects of EMA content and temperature on network parameters such as effective crosslink density（ve）, molar mass between crosslinks （Mc） and polymer-water interaction parameter （X） of hydrogels were studied on the basis of swelling and tensile properties. The increase of EMA content can enhance hydrophobic bonding within hydrogel, leading to the decrease in equilibrium water content （EWC） and the increase in volume fraction of polymer in bydrogel （φ2）, and tensile strength, Young＇s modulus, vc and X values of hydrogels also increased and M, decreased. When the temperature is increased from 275 K to 304 K, the hydrogel EMA25/HEMA75 undergoes decreasing in EWC and increasing in φz and X values.