Surface photografting polymerization of vinyl acetate, maleic anhydride, and their charge‐transfer complex. VIII. Charge‐transfer complex (4)

Abstract

ABSTRACT:In view of the complexity of surface photografting polymerization of vinyl acetate/maleic anhydride (VAC/MAH) binary monomer systems, a novel method was adopted in the present article to obtain insight into the relevant grafting copolymerization mechanism. This method includes two steps: semibenzopinacol dormant groups were first introduced onto LDPE film by UV-irradiation and then thermally reactivated to produce LDPE macromolecular free radicals, which initiated the grafting copolymerization of VAC and MAH. It was demonstrated that, in the first step, the solvent used to introduce benzophenone (BP) to LDPE film largely affected the subsequent grafting copolymerization, which was closely related to the affinity of the solvent toward the substrate. The monomer feed composition had considerable influence on both the grafting and nongrafting copolymerization; however, the maximum copolymerization rates did not appear in the polymerization system with [VAC]/[MAH] being 1 : 1, but, in the system with a bit more VAC than MAH, as the total monomer concentration was raised, the maximum copolymerization rates tended to appear in the system with [VAC] equal to [MAH]. The relationship between the total copolymerization rate (RP) and monomer concentration was determined to be LnRP ϰ [VAC ϩ MAH]1.83 . All of these results indicated that both charge transfer (CT) complex formed by VAC and MAH and free monomers took part in grafting copolymerization. This feature differentiated the surface grafting copolymerization of VAC/MAH from the well-studied thermally induced alternating copolymerization of VAC/MAH.

表面光接枝聚合反应新进展

“…或N-乙烯基吡咯烷酮(NVP) [41] 等组成单体对后, 则很容易进行表面光接枝聚合并 获得较高的单体转化率、接枝率和接枝效率, 其中 MAH与上述诸单体间形成CTC是接枝聚合赖以发生 的关键所在. Deng等人 [33,34] [44]…”

Simultaneous Photografting of Two Organic Groups on a Gold Surface by using Arylazo Sulfones as Single Precursors

“…On the other hand, the preparation of mixed layers in order to enrich the surface chemistry has received less attention. As an example, mixed monomers providing charge transfer complexes such as styrene and vinyl acetate or maleic anhydride have been photografted to improve the surface properties of PET. , Two incompatible enzymes (trypsin and transglutaminase) were separately encapsulated into different poly­(ethylene glycol) (PEG) network layers and grafted on a polyethylene film via visible-light-induced living photografting polymerization . Electrografting also allows the preparation of mixed layers.…”

Effect of poly(ethylene‐co‐vinyl acetate) additive on mechanical properties of maleic anhydride‐grafted acrylonitrile butadiene styrene for coating applications

“…Later, Rzayev has published a review on MA grafting and its iso‐structural analogues with various polyolefins . There are many reports available on MA‐ g ‐ABS polymer prepared by various techniques . The melt grafting technique gained a superior position among all the other techniques because of the ease of processing.…”