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化学学报
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化学学报 ›› 2011, Vol. 69 ›› Issue (22): 2710-2716. 上一篇    下一篇

研究论文

PVA增强P(AAEA-co-AA)温度敏感性水凝胶的合成及其性能研究

林松柏*，袁丛辉，柯爱茹，李云龙，欧阳娜   

  1. (黎明职业大学轻纺工程系 泉州 362000)
  • 投稿日期:2011-01-20 修回日期:2011-06-09 发布日期:2011-06-20
  • 通讯作者: 林松柏 E-mail:lsb@lmu.edu.cn

Synthesis and Properties of PVA Enhanced P(AAEA-co-AA) Temperature Sensitive Hydrogels

LIN Song-Bai, YUAN Cong-Hui, KE Ai-Ru, LI Yun-Long, OUYang-Na   

  1. (Liming Vocational University, Quanzhou 362000)
  • Received:2011-01-20 Revised:2011-06-09 Published:2011-06-20
  • Contact: Song-Bai Lin E-mail:lsb@lmu.edu.cn

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以4-乙酰基丙烯酰乙酸乙酯(AAEA)、丙烯酸(AA)以及PVA为原料, 通过自由基溶液聚合法, 制备了PVA-P(AAEA-co-AA)半穿网络型(s-IPN)水凝胶. 红外分析表明, AAEA主要以烯醇式结构存在, 并且由于PAAEA, PAA以及PVA之间较强的氢键作用, 使得PAAEA以及PVA分子上的C—O伸缩振动吸收峰移向了低波数处. 电镜分析表明, PVA能贯穿于P(AAEA-co-AA)交联网络中, 从而有效阻碍凝胶的相分离|而XRD研究发现, 当PVA用量较少时, PVA能均匀的贯穿于凝胶网络中, 形成完善的互穿网络结构, 当PVA用量过高时, PVA不能有效地贯穿于聚合物交联网络中而出现结晶. 采用DSC对s-IPN水凝胶的体积相转变进行了研究, 结果表明, 该s-IPN水凝胶的体积相转变温度(VPTT)在54.0至57.8 ℃之间, 并且随着PVA用量的增加, 凝胶的VPTT逐渐升高. 研究了该s-IPN水凝胶的抗压缩性能, 结果表明, PVA与P(AAEA-co-AA)形成的半互穿网络结构能有效提高凝胶的抗压缩强度, 其最大抗压缩强度可达8.4 MPa. 对凝胶的温度敏感性研究发现, 当外界温度低于VPTT时, 凝胶能保持溶胀状态|而当温度高于VPTT时, 凝胶的平衡溶胀度迅速下降, 表现为温度敏感性.

关键词: 水凝胶, 温度敏感性, 机械性能, 体积相变

Semi interpenetrating polymer networks (s-IPN) hydrogels composed of poly(vinyl acohol) (PVA), poly(4-acetyl acryloyl ethyl acetate-co-acrylic acid) [P(AAEA-co-AA)] were synthesized via solution polymerization using acrylic acid (AA), 4-acetyl acryloyl ethyl acetate (AAEA) and PVA. Fourier-transform infrared (FT-IR) was used to confirm the chemical structure of the s-IPN hydrogels. The results showed that the AAEA mainly existed as enol form, making the peak of C—O stretching in the IR spectra of PVA-P(AAEA-co-AA) flow to low wave numbers. This is attributed to the formation of strong hydrogen bonds between PVA, PAA and PAAEA. SEM macrographs revealed that PVA impenetrated into the P(AAEA-co-AA) ploymer networks homogeneously, and barricaded the phase separation of the hydrogels. XRD analyses showed that the hydrogels formed perfect s-IPN structure when the dosage of PVA was low. However, when the dosage of PVA was high, PVA could not impenetrate in P(AAEA-co-AA) ploymer networks homogeneously, making the crystallization of PVA increase significantly. The volume phase transition temperature (VPTT) of the s-IPN hydrogels was determined by their respective DSC thermograms of swollen hydrogel specimens. The results showed that the VPTT of the hydrogels ranged from 54.0 to 57.8 ℃, and increased with the increasing dosage of PVA. The stress strength of s-IPN hydrogels was studied, the results showed that the s-IPN structure formed between PVA and P(AAEA-co-AA) improved the strength of the hydrogels significantly, and the maximum stress strength of the hydrogel was about 8.4 MPa. The temperature sensitivity of the s-IPN hydrogels was also investigated, the results showed that the hydrogels exhibited excellent temperature sensitivity. When the temperature was lower than VPTT, the hydrogels kept at a swelling state, but when the temperature was higher than VPTT, the hydrogels deswelled evidently.

Key words: hydrogel, temperature sensitivity, mechanical strength, volume phase transition