B. Lessard, C. Aumand-Bourque, R. Chaudury, D. Gomez, A. Haroon, N. Ibrahimian, S. Mackay, M.-C. Noel, R. Patel, S. Sitaram, S. Valla, B. White, M. Maric
April 6, 2013
Telechelic poly(ethylene-ran-butylene) initiator terminated with [tert-butyl[1-(diethoxyphosphoryl)-2,2-dimethylpropyl]amino] nitroxide groups (PEB-(SG1) 2 ) was used to initiate the controlled radical copolymerization of maleic anhydride (MA) and styrene (ST). The ST/MA copolymerizations were performed in 1,4-dioxane at 110°C and resulted in PEB-b-P(ST-ran-MA) 2 triblock copolymers with relatively narrow molecular weight distributions (M¯m/M¯n≈1.5). Gel permeation chromatography (GPC) indicated that the initiator used was ≈93% efficient. The resulting copolymers were then blended as 20 wt.% dispersions in nylon 6 (PA6) at 230°C. With as little as 10 mol.% of MA in the feed to make the PEB-b-P(ST-ran-MA) 2 , blends were deemed dynamically compatibilized based on the reduced particle size. All of the PEB-b-P(ST-ran-MA) 2 /PA6 blends resulted in a minor phase particle size D¯vs=0.1 μm while the PEB-b-P(ST)/PA6 blend had D¯vs=1.15 μm (i.e. no MA in the copolymer). Tensile testing revealed yield stresses and strains decreased steadily from pure PA6 to non-reactive PEB-b-P(ST) 2 /PA6 to PEB-b-P(ST-ran-MA) 2 /PA6. However, no difference in tensile properties was observed between PEB-b-P(ST-ran-MA) 2 /PA6 samples made from PEB-b-P(ST-ran-MA) 2 copolymer of varying MA content.