A polyolefin encapsulant material designed for photovoltaic modules: from perspectives of peel strength and transmittance

摘要

A secondary master batch process had been applied to design a polyolefin encapsulant material for photovoltaic modules, in which the polymer blend was composed of polyolefin elastomer (POE) and linear low-density polyethylene (LLDPE) with the addition of the cross-linking agent of tert-butylperoxy 2-ethylhexyl carbonate (TBEC) and silane coupling agent of gamma-methacryloxypropyl trimethoxy silane (KH570). The rheological property from Haake torque rheometer illuminated that the chemical cross-linking reaction could take place between the POE and TBEC. The LLDPE was added for further increasing the cohesion of polymer blend by obtaining much more physical cross-linking points from the physical entanglement between the flexible chains of LLDPE and the amorphous zone of POE. However, the transmittance of polymer blend ran down with the rise of LLDPE content within the polymer blend. The number and site of melting points of polymer blend by the DSC analysis show that there was compatibility between the POE and LLDPE within the polymer blend; meanwhile, the resultant molecular structures of the polymer blend also had been explained by the FTIR spectra. These results unanimously illuminated that it was a feasible solution for fabricating the polyolefin encapsulant material for photovoltaic modules.