Application of a novel ethylene-vinyl acetate-graft-2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane (EVA-g-V4)material for photovoltaic encapsulation film

Ethylene-vinyl acetate (EVA)grafted 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane (V4) polymer EVA-g-V4 was prepared by free-radical solution grafting reaction. The results of the purified grafted products by FT-IR, 1 H NMR, XRD, TG and DSC show that V4 has been successfully grafted onto the main chain of EVA. The effects of the dosage of V4 and BPO on grafting ratio were studied. When the dosage of V4 was 6.0 wt%, and the dosage of BPO was 0.8 wt%, the grafting ratio was up to 1.4%. The cross-linking behaviour was verified by SEM. Compared with pure EVA film, the peel strength, mechanical properties, volume resistivity and hydrophobicity of EVA-g-V4 film all improved with increasing grafting ratio. This work provides a new option in the field of photovolatic encapsulation materials.