Creep Analysis of Bamboo High-Density Polyethylene Composites: Effect of Interfacial Treatment and Fiber Loading Level

The effect of chemical treatment at fiber-plastic interface and fiber loading level on creep property of bamboo fiber high-density polyethylene (BF/HDPE) composites was investigated. For single modifier systems, the use of maleic anhydride grafted polyethylene (PE-g-MA) as a coupling agent helped reduce the creep and achieved the optimum effect at the 5.7% loading level. The addition of either a semicrystalline or an amorphous MA grafted ethylene propylene rubber (sEPR-g-MA or aEPR-g-MA) as an impact modifier increased the creep. For the combined modifiers, the use of PE-g-MA in EPR-g-MA modified composites gradually improved creep performance. Four-element Burgers model was shown to fit measured creep data well only within the specified test period. However, both partially stretched Burgers (PSB) model and fully stretched Burgers (FSB) model could be applied for characterization and prediction when the stretching exponent was fixed at certain given values. The FSB model offered a better long-term prediction based on the short-term creep data. Time-temperature superposition technique produced smooth master creep curves through horizontal shifts, but it slightly over-predicted the long-term creep for most composite systems. POLYM. COMPOS., 32:692-699, 2011. (c) 2011 Society of Plastics Engineers