温度对聚(N-异丙基丙烯酰胺)水凝胶内部结构及性能影响的研究

Effect of Temperature on the Internal Microstructures and Properties of Poly(N-Isopropylacrylamide) Hydrogels

分别在0℃、25℃、60℃的水溶液中通过自由基交联聚合,制备了聚(N-异丙基丙烯酰胺)水凝胶。研究了温度对于水凝胶内部微观结构的影响并分析了内部微观结构与水凝胶性能之间的关系。用扫描电镜(SEM)、红外光谱仪(FT-IR)和差示扫描量热仪(DSC)对制备的凝胶进行表征。结果表明,3种水凝胶具有相同的化学组成和相转变温度,但其内部微观结构有较大差别。通过测试水凝胶的温敏性、溶胀动力学和脉冲响应性发现:改变温度可以有效地改变水凝胶的内部结构,在较高温度下制得的水凝胶具有较高的溶胀率、较快的去溶胀速率和较强的脉冲响应性。

Poly( N-isopropylacrylamide)( PNIPAAm) are fabricated by free radical polymerization in aqueous solution at three different temperature,0 ℃,25 ℃ and 60 ℃. The effect of fabrication temperature on their internal microstructures were studied. The relationships between the internal microstructures of PNIPAAm and their properties were also analyzed. The PNIPAAm hydrogels was characterized by scanning electron microscopy( SEM),differential scanning calorimetry( DSC) and Fourier trans-form infrared spectroscopy( FT-IR). The results show that the chemical compositions and the phase transition temperature of different hydrogels are similar,but their microstructures are different. By testing the temperature sensitivity,swelling kinetics and impulse response of the hydrogel,it was found that the internal structure of the hydrogel can be changed by changing the fabrication temperature and the hydrogels which were prepared at higher temperature had a higher swelling ratio,a faster rate of swelling and a stronger impulse response.