Polymer compositions for photovoltaic modules

A method of making an encapsulant film for use in photovoltaic modules, the method comprising:

• providing a polymer composition comprising:
• (a) 100 phr of a polyolefin elastomer containing a copolymer of ethylene and at least one alpha-olefin having from 3 to 20 carbon atoms,
• (b) 0.1 to 10 phr of a hydrogenated block copolymer selected from:
• (i) a multi-arm hydrogenated block copolymer having a general structure (“R”)nX, wherein X is a residue of a coupling agent and n is an integer from 4 to 20;
• (ii) a hydrogenated styrenic block copolymer comprising at least one block “S” and at least one block “R,” each block “S” is composed of vinyl aromatic units and has a molecular weight (Mp) of 70 to 130 kg/mol, measured according to ASTM D5296-19;
• and
• (iii) mixtures thereof, and
• wherein:
• each block “R” comprises hydrogenated diene units, and
• the hydrogenated styrenic block copolymer has a vinyl aromatic unit (VAC) content of <40 wt. %, measured by 1H NMR;
• (c) 0.1 to 5 phr of a cross-linking agent;
• and
• (d) 0.1 to 10 phr of at least one additive;
• forming the encapsulant film by casting, electrospinning, extrusion, compression, or coating;
• and
• curing the encapsulant film at a temperature of 80 to 220° C.;
• and
• wherein after curing, the encapsulant film has a static friction coefficient >0.39 and a dynamic friction coefficient >0.45, both measured according to ASTM D1894.