The effect of aging conditions on the mechanical properties of wood fiber-polystyrene composites: I. Chemithermomechanical pulp as a reinforcing filler

Abstract

The mechanical properties and dimensional stability of composites consisting of hardwood aspen chemithermomechanical pulp in polystyrene were evaluated under various aging conditions, including variation of the testing temperature (from +25°C to −40°C), exposure to boiling water, and heating in an oven at +105°C. The influence of coupling agent, e.g. 3% poly[methylene(polyphenyl isocyanate)], as well as treatments such as coating and grafting, on the properties of the composite materials have also been studied. The treated composites showed superior mechanical properties and better dimensional stability compared with non-treated fiber-filled composites. Moreover, the mechanical properties, particularly of treated composites, were enhanced compared with those studied under ordinary conditions. Dimensional stability under the same conditions also supports this observation. The greater resistance of the treated composites under different aging conditions suggests the existence of an efficient interfacial area between the fiber and the polymer matrices.