Effect of antiaging agents on the outdoor natural weathering of bamboo powder/polypropylene foamed composites

摘要

The effect of outdoor natural weathering on the properties of injection molded 33 wt% bamboo powder (BP)/polypropylene (PP) foamed composites with and without the antioxidant and hindered amine light stabilizers (HALS) were investigated. The composites containing the antiaging agents had higher color stability, slightly greater retentions of flexural modulus, tensile and notched impact strengths, higher creep resistance, and better rheological stability than the reference composite. The antiaging agents of pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) and poly-(n-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidyl succinate) had more beneficial effect than n-octadecyl--(4-hydroxy-3,5-di-tert-butyl-phenyl)-propionate and bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate. After 12 months of exposure, oE(*) decreased from 22.8 of the reference composite to 9.9 of the composite with the antiaging agents. Rheological behavior results indicated that the storage modulus, complex viscosity, and non-Newtonian fluid index of composites containing the antiaging agents were slightly increased. Natural weathering caused less decreases in the storage and loss moduli, crossover modulus, relaxation time, and average molecular weight for composites containing the antiaging agents than those for the reference composite. Environmental scanning electron microscopy (ESEM) observation confirmed the improved surface durability for composites containing the antiaging agents. J. VINYL ADDIT. TECHNOL., 22:311-319, 2016. (c) 2014 Society of Plastics Engineers