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首页> 外文期刊>Journal of Applied Polymer Science >PHOTOPOLYMERIZATION SYNTHESIS OF POLY(N-ISOPROPYLACRYLAMIDE) HYDROGELS
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PHOTOPOLYMERIZATION SYNTHESIS OF POLY(N-ISOPROPYLACRYLAMIDE) HYDROGELS

机译：聚（N-异丙基丙烯酰胺）水合物的光聚合

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Poly(N-isopropylacrylamide) (NIPAAm) gels were formed by photopolymerization of NIPAAm in the absence of a crosslinker using a water solvent at 25 degrees C. Factors affecting formation were the wavelength region of irradiated light, the type of photoinitiators, and the concentrations of the photoinitiator and monomer. A high-pressure mercury lamp (400 W)was used as a light source. An NIPAAm concentration of 10 wt % and irradiation time of 15 h was used for the photopolymerization. The gel (68% yield) was formed when the quartz glass system was used, but no gelation was observed for the Pyrex glass system that transmits light with lambda > 290 nm. The gel (100% yield) was easily formed, even in the latter system, when 30 mmol/L of hydrogen peroxide and potassium persulfate were used as the photoinitiator. Water soluble photoinitiators such as ferric chloride and sodium anthraquinone-2,7-disulfonate were not effective for the gel formation. Yield of the gel increased with increasing the potassium persulfate concentration (1-30 mmol/L), but it decreased when a high concentration of hydrogen peroxide (60 mmol/L) was used. The gel yield increased with the NIPAAm concentration (5-20 wt %). The degree of swelling of the resultant poly(NIPAAm) gels, which was measured by immersing the gels in water at various temperatures (0-50 degrees C) for 24 h, steeply decreased at about 30 degrees C with increasing temperature, exhibiting a temperature-responsive character. The gels swelled and shrank in water below and above the temperature, respectively. The extent of the character depended on the concentrations of hydrogen peroxide and monomer. The formation mechanism of the gel in the photopolymerization of NIPAAm using hydrogen peroxide photoinitiator was discussed. (C) 1997 John Wiley & Sons, Inc. [References: 21]
机译：聚（N-异丙基丙烯酰胺）（NIPAAm）凝胶是在不存在交联剂的情况下，在25°C下使用水溶剂通过在不存在交联剂的条件下进行光聚合而形成的。影响形成的因素包括照射光的波长范围，光引发剂的类型和浓度的光引发剂和单体。使用高压汞灯（400 W）作为光源。 NIPAAm浓度为10 wt％，照射时间为15 h用于光聚合。当使用石英玻璃系统时，形成了凝胶（68％的收率），但是对于透射λ> 290nm的光的派热克斯玻璃系统没有观察到凝胶化。当使用30 mmol / L的过氧化氢和过硫酸钾作为光引发剂时，即使在后一体系中，也容易形成凝胶（100％收率）。水溶性光引发剂，例如氯化铁和2，7-二磺酸蒽醌钠对凝胶的形成无效。凝胶的产率随着过硫酸钾浓度（1-30 mmol / L）的增加而增加，但是当使用高浓度的过氧化氢（60 mmol / L）时，产率降低。凝胶产率随NIPAAm浓度（5-20​​wt％）而增加。所得聚（NIPAAm）凝胶的溶胀度是通过将凝胶在各种温度（0-50摄氏度）下浸入水中24小时来测量的，随着温度的升高，溶胀度在约30摄氏度时急剧降低，表现出一定的温度反应灵敏的角色。凝胶分别在低于和高于温度的水中溶胀和收缩。特征的程度取决于过氧化氢和单体的浓度。讨论了过氧化氢光引发剂在NIPAAm光聚合中凝胶的形成机理。 （C）1997 John Wiley＆Sons，Inc. [参考：21]

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