The Accelerated Thermo-Oxidative Aging Characteristics of Wood Fiber/Polycaprolactone Composite: Effect of Temperature, Humidity and Time

Abstract

This study investigated the characteristics of wood fiber/polycaprolactone composite after an artificial accelerated thermo-oxidative aging treatment. The effect of time, temperature and humidity during the treatment on their mechanical, chemical and morphology properties were evaluated. The composite was prepared from melted wood fibers and modified polycaprolactone by a molding process. A temperature and humidity controllable test chamber was used for the thermo-oxidative aging of the composite. The thermo-oxidative aging caused surface of the composite to be much more rougher and even a few cracks and holes appeared on it. According to the spectra of Fourier Transform Infrared (FTIR) and Gel Permeation Chromatography (GPC), C=O in the molecular chain of polycaprolactone was hydrolyzed and C–O was broken after the aging treatment, which resulted in a reduction in average molecular weight of the composite. Moreover, results showed that the mechanical strength decreased a lot with the increase in time, temperature and humidity, and the effect of temperature and humidity was more significant compared with that of time. Controlling the temperature and humidity during thermo-oxidative aging treatment could accelerate the aging of composite, which provided a quick and effective method for evaluating the aging resistance of the composite.