耐电压型聚P(NIPAAm-co-DMAEMA)水凝胶的合成与性能

Synthesis and Properties of Voltage Tolerance P(NIPAAm-coDMAEMA) Hydrogels

电场敏感水凝胶是由高分子三维网络与溶剂水组成的多元体系,并且在电场作用下会产生可逆弯曲或消溶胀的水凝胶。本文以异丙基丙烯酰胺(NIPAAm)和甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)为单体,N,N′-亚甲基双丙烯酰胺为交联剂,过硫酸铵和亚硫酸氢钠为氧化还原引发剂,采用水溶液聚合法制备了一系列电场敏感性水凝胶,研究了不同质量分数的NaCl溶液、温度、接触电场对水凝胶溶胀率的影响。研究表明,合成的一系列P(NIPAAm-co-DMAEMA)水凝胶中,随着单体NIPAAm量的增加,在去离子水中的平衡溶胀率下降,同时随着NaCl质量分数的增加,平衡溶胀率下降,但即使在质量分数为0.9%的NaCl溶液中,最大溶胀率仍达89g/g,即保水率44%;共聚得到的水凝胶LCST温度在43℃左右,有望成为良好的温敏性材料。在接触电压刺激下,随着样品水凝胶中DMAEMA含量的增加,水凝胶的质量保持率Rm依次减小。传统阴离子单体或阳离子单体聚合而成的水凝胶在电场作用下消溶胀十分明显,而本文采用阳离子单体与非离子单体共聚合成得到的水凝胶的Rm与时间的关系可以用拟合方程较好地描述,根据得到的拟合方程外推,该水凝胶在通电360min后保水率仍可达53%。这种良好的耐电压性,使该水凝胶更好地应用于人工肌肉和仿生技术及人造保险丝。

The electric-field sensitive hydrogel,composed of macromolecule＇s three-dimensional network and water,could bend and deswell under the action of an electric field.A series of electric field sensitive gels were prepared by free-radical polymerization with N-isopropylacrylamide（PNIPAAm） and N-（2-（dimethylamino）ethyl）-methacrylamide（DMAEMA） as the monomers,N,N＇-methylene bisacrylamide as the crosslinking agent,ammounium persulfate and sodium bisulfite as the redox initiator.The influences of the concentration of aqueous NaCl solutions,temperature and contacting DC electric field on the swelling ratios of the hydrogels were studied in detail.It is shown that the equilibrium swelling ratios decrease as the NIPAAm and the concentration of NaCl increase.Even in a normal saline with concentration of 0.9%,the equilibrium swelling ratio can be around 89g/g,that is to say,the retention is around 44%.The obtained hydrogels,with LCST around 43℃,could be a kind of temperature sensitive materials.Under the action of a contacting DC electric field,the Rm of hydrogels decreases as DMAEMA increases.Traditionally,the hydrogel prepared by anion or cation monomer,could deswell in an electric field.But in this paper,the hydrogel was prepared by copolymerization with anion monomer and non-ionic,the relationship between Rm and time could be described with fitting formulas,which indicate that the water retention could reach 53%.Due to the excellent voltage tolerance,the gels can be applied in the artificial muscle and bionic technology,and can substitute conventional metal fuses in the future.