Graft Copolymerization of Methylmethacrylate onto Ximeniaamericana Seed Oil-Based Polyurethanes using an initiator-accelerator couple system: Effect of initiation time on Mechanical, Swelling and Morphological Properties

Graft copolymerization continuestoplay important role in the modification of wide range of polymer materials for industrial application. The objective of this study was to investigate the effect of variedinitiation time of benzoyl peroxide-N,N-dimethyl- para -toludinecouple system by free radical solution polymerization on the mechanical, swelling and morphological properties of polyurethane-graft-polymethylmethacrylate copolymer using appropriate standard methods. The tensile and flexural properties for HDPU-1.02-g-PMMA and TDPU-1.02-g-PMMA increased within (20-30 min.) initiation time and decreased thereafter, these parameters for MDPU-1.02-g-PMMA, increased over the whole range of initiation time (20-40 min.). The copolymers showed maximum and minimum swelling in chloroform and propanol respectively, with exception of propanol, MDPU-1.02-g-PMMA copolymer presents the highest swelling in other solvents. HDPU-1.02-g-PMMA and TDPU-1.02-g-PMMA copolymers prepared at40 min. initiation time showed macrophase separation. In contrast, MDPU-1.02-g-PMMAprepared at identical condition, indicates an encapsulated polymethylmethacrylate chain within the MDPU-polymer matrix. The results showed that Ximeniaamericana seed oil was an effective precursorfor polyurethane-graft-polymethylmethacrylate copolymers with physico-mechanical properties characterized by structural orientation of the base polyurethane matrix and polymerization initiation time.