• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.62-68
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• 2011

In the study, acrylate copolymer as MMA-co-GMA-co-AA with a high hardness and flexibility was synthesized for applying to the clear protection film, where GMA was used as a mediator to enhance polymerization-efficiency between MMA and AA. With an increase of GMA content, molecular weight and hardness of acrylate copolymer increased, however, flexibility decreased. With an increase of AA content, its molecular weight and hardness decreased, however, flexibility increased. Molar ratio of GMA/MMA and AA/GMA were optimized as 1.6 and 1.8, respectively, at 30 g of MMA to enhance hardness and flexibility of acrylate copolymer film. Molecular weight and Tg of the acrylate copoylmer were 13,300 g/mol and 136.5 $^{\circ}C$, respectively. Hardness of the coated film at 1.4 g/$m^2$ of spread was 1 H and no crack was observed at expansion ratio of 5% and 15%, respectively. Hardness of film was improved to 3 H by increasing spread of 4.1-4.6 g/$m^2$.