MTMP光接枝改性聚乙烯薄膜的研究

以二苯甲酮为光引发剂 ,实现了反应型受阻胺哌啶醇衍生物 4- (甲基丙烯酰氧基 ) -2 ,2 ,6,6-四甲基哌啶醇酯 ( MTMP)作为单体在聚乙烯薄膜 ( L LDPE)表面进行液 -固相光接枝聚合以改善其光稳定化性能 .采用全反射红外光谱 ( ATR- FTIR)对接枝后样品膜进行了表面羰基分析 ,并以黄度指数 ( YI)为表征参数对光接枝前后的 L LDPE薄膜样品进行了光氧化降解试验 .结果表明 :在 MTMP- g- L LDPE光接枝体系中 ,接枝率分别与辐照时间和单体溶液浓度呈线性增长关系 ;接枝后 L LDPE样品膜的羰基特征吸收峰 ( A172 5　cm- 1 )和接枝率随辐照时间呈同步增长规律 ;接枝后 LLDPE样品膜的光稳定性 ( 1 /YI)随接枝率的增加而提高

Studies on the Surface Modification of LLDPE Film by the Photo-grafting of MTMP

The surface modification by the photografting of r HALS(reactive hindered amine light stabilizers)on a commercial polyolefin thin film was studied.The process proceeded by photo initiated grafting copolymerization of 4 methacryloyloxy 2,2,6,6 tetramethyl piperidine(MTMP),a reactive HALS,onto the surface of linear low density polyethylene(LLDPE) thin film,presoaked in the benzene solution containing benzophenone(BP) initiator and MTMP monomer and UV irradiation for short time under nitrogen atmosphere.The results show that the increase of carbonyl absorbance(or CV)was increased with the concentration of MTMP monomer in the presoaking solution,the grafting yield and the irradiating time.The photo stabilizing performance of LLDPE film inhibiting photo oxidant degradation was greatly improved by the grafting layer of MTMP(r HALS).Yellowness Index(YI)of the LLDPE g MTMP films is much lower than that of the blank through the 4 000 hours photo oxidation,an evidence for improvement of the photo stability.Surface modification of LLDPE film by photo grafted with r HALS monomer has thus been proved efficient for the photostabilization of LLDPE.