摘要
以含偶氮苯的三硫代碳酸酯(TTC-AZO)作为RAFT试剂,将N-异丙基丙烯酰胺(NIPAM)通过可逆加成断裂链转移(RAFT)自由基聚合制备了具有温度和光双重敏感的含偶氮苯端基的聚N-异丙基丙烯酰胺(PNIPAM-AZO),通过紫外-可见吸收光谱、红外光谱和核磁共振氢谱对其结构进行了表征.光敏性研究表明,PNIPAM-AZO聚合物在水溶液中能够进行快速、可逆的光致顺反异构反应.温敏性结果表明,PNIPAM-AZO聚合物的低临界溶解温度(LCST)比聚N-异丙基丙烯酰胺(PNIPAM)聚合物低,且随着PNIPAM-AZO聚合物数均分子量的增加和聚合物水溶液浓度的升高,其LCST温度均下降.分子量分布变宽,其LCST温度升高.在较高的聚合物水溶液浓度下,随着α-环糊精(α-CD)加入量的增加,聚合物的LCST温度先降低而后逐渐升高;在较低的聚合物水溶液浓度下,少量α-CD的加入使得聚合物的LCST温度升高,进一步增加α-CD的量LCST温度基本不变.紫外光和可见光交替照射PNIPAM-AZO聚合物水溶液,其LCST温度呈现出可逆的升高和降低,LCST温度的改变幅度为0.7 K,具有光可调控的温敏特性.
Azobenzene-terminated PNIPAM （PNIPAM-AZO） with temperature and light dual-sensitive properties was synthesized by reversible addition-fragmentation chain transfer （RAFT） polymerization of N- isopropylacrylamide （NIPAM） with azobenzene-containing trithiocarbonate （TTC-AZO） RAFT reagent, and the structure was confirmed by UV-Vis, FTIR and 1H-NMR spectroscopy. The thermosensitivity and photosensitivity of PNIPAM-AZO aqueous solutions were investigated. The results show that PNIPAM-AZO aqueous solutions have rapid and reversible trans-cis photoisomerization properties. The lower critical solution temperature （LCST） of PNIPAM-AZO is lower than that of poly（N-isopropylacrylamide） （PNIPAM） , and the LCST of PNIPAM-AZO decreases with the increase of both polymer number molecular weight and aqueous solution concentration, and increases as the molecular weight distribution broadens. The LCST of PNIPAM-AZO aqueous solutions of higher concentrations first decreases and then increases when the addition amount of ct- cyclodextrin （a-CD） increases. However, for lower concentrations of PNIPAM-AZO aqueous solutions, the LCST first increases and then remains fairly constant. When subjected to ultraviolet （UV） and visible light irradiation alternately,the LCST of PNIPAM-AZO aqueous solution increases and decreases reversibly with a temperature amplitude of 0.7 K,which shows light-tunable thermosensitivity.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2013年第10期1291-1297,共7页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号50903018)
安徽省高等学校自然科学基金(基金号KJ2011A209)
阜阳师范学院科研项目(项目号2011CXY04)资助
关键词
聚N-异丙基丙烯酰胺
温敏性
光敏性
偶氮苯
分子识别
Poly（N-isopropylacrylamide）, Thermosensitivity, Photosensitivity, Azobenzene, Molecular recognition
