光接枝LDPE膜的结晶行为和表面形态

研究了空气气氛中，丙烯酸和丙烯酰胺单体对低密度聚乙烯（LDPE）光接枝的影响及光接枝LDPE的结晶行为和表面形态。结果表明，与丙烯酰胺单体相比，LDPE接枝丙烯酸的聚合反应速度较快，有效接枝率较高。与未接枝膜相比，光接枝LDPE膜对水的接触角显著降低，亲水性显著增强。光敏剂二苯甲酮（BP）与光敏促进剂N，N-二甲基苯甲酸乙酯（EDAB）的协同作用，有效地促进接枝反应的进行，使LDPE的有效接枝率增加。IR结果表明，LDPE膜表面已接枝了丙烯酸或丙烯酰胺。DSC结果表明，LDPE的光接枝聚合反应主要发生在表面或无定形区。SEM结果表明，随有效接枝率增加，LDPE表面粗糙度增加，进一步证明光接枝反应主要发生在取合物表面。

Crystalline behavior and surficial morphology of photografted low density polyethylene

The effect of acrylic acid (AAc) and acrylamide (AAm) on the photografting ratio in air atmosphere,and the crystalline behavior and surficial morphology of grafted LDPE were studied. In comparison with AAm, the grafting ratio of AAc on LDPE was high. Ethyl dimethylaminobenzoate (EDAB) worked as a synergistic agent of benzophenone (BP) and enhanced the grafting ratio. With the increase of grafting ratio, the water contact angle on grafted LDPE film decreased greatly. The appearance of additional IR spectra peaks at 1 703.6, 1 602.7 and 1 672.7cm -1 indicated that both AAc and AAm had been grafted onto LDPE. The photografting did not affect the crystalline behavior of LDPE and occurred mainly on the surface of LDPE. The result of SEM showed that with the increase of grafting ratio the roughness of grafted LDPE increased, which further showed that grafting was mainly on the surface.