Copolymer of phase change material for thermal management of PV modules
View Patent ↗The present invention relates to phase change materials (PCMs) which may be used with photovoltaic (PV) modules. More specifically, solid/solid PCMs having a polyolefin backbone polymer and a crystallizable side chain are provided. Preferably, the solid/solid PCM has a copolymer backbone having a polyolefin repeating unit, and the crystallizable side chains are grafted onto the copolymer backbone. Most preferably, the copolymer is poly(ethylene-co-glycidyl methacrylate) (PE-co-GMA), and polyethylene glycol (PEG) is the crystallizable side chain. Photovoltaic modules and backsheets for photovoltaic modules having solid/solid PCMs are also provided.
1. A solid/solid phase change material comprising:
a poly(ethylene-co-glycidyl methacrylate) backbone copolymer; and,
a crystallizable side chain of a polyethylene glycol grafted onto the backbone copolymer by the reaction between epoxide of the glycidyl methacrylate and a hydroxyl group of the crystallizable side chain,
wherein the solid/solid phase change material experiences a phase change at a temperature in the range of from about 30° C. to about 75° C.
2. The solid/solid phase change material of claim 1 , wherein the polyethylene glycol has a molecular weight of about 4000.
3. The solid/solid phase change material of claim 1 , wherein the solid/solid phase change material experiences a phase change at a temperature in the range of from about 40° C. to about 70° C.
4. The solid/solid phase change material of claim 1 , wherein the solid/solid phase change material has a latent heat of phase change of at least 40 kJ/kg.
5. A backsheet for a photovoltaic module comprising a solid/solid phase change material comprising:
a poly(ethylene-co-glycidyl methacrylate) backbone copolymer; and
a crystallizable side chain of a polyethylene glycol grafted onto the backbone copolymer by the reaction between epoxide of the glycidyl methacrylate and a hydroxyl group of the crystallizable side chain.