This paper investigates the effects of cellulose content and processing conditions on the mechanical properties and foaming behavior of injection molded cellulose fiber reinforced polypropylene composite foams. Composite foams were injection molded using an advanced structural foam molding machine with N2 as a physical blowing agent. Foamed specimens were prepared at different injection speeds and void fractions. The mechanical properties and foam morphologies of the specimens were evaluated. The results suggested that the specific flexural modulus was increased and the specific flexural strength and Izod impact strength were maintained by foaming, and that the strength, modulus, and notched Izod impact strength increased with the increase of cellulose content. Additionally, the results suggested that the cell morphology of the composite foams was improved by the increase of void fraction and the addition of cellulose fiber.
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