Effect of maleated polypropylene as coupling agent for polypropylene composites reinforced with hemp strands

MUTJÉ, PERE; VALLEJOS, MARÍA E.; GIRONÈS, JORDI; VILASECA, FABIOLA; LÓPEZ, ÁNGEL; LÓPEZ, JOAN P.; MÉNDEZ, JOSÉ A.

JOURNAL OF APPLIED POLYMER SCIENCE

JOHN WILEY & SONS INC

Lugar: HOBOKEN, USA; Año: 2006 vol. 102 p. 833 - 840

0021-8995

New composites based on poly(propylene) (PP) as polymer matrix and hemp strands as natural reinforcement have been developed by injection-moulding. The materials were previously mixed in a two roll mill to induce the dispersion of the fibre inside the polymer. To improve the adhesion between both components, maleated poly(propylene) (MAH-PP) was added as coupling agent, at 4% wt/wt with respect hemp strands. The addition of this amount of this coupling agent to the formulation modified with a 40% wt of hemp strands increases the ultimate tensile strength (ót) and flexural strength (óf) up to 49% and 38%, respectively, compared with the composite without coupling agent. The interaction between the surface of hemp strands and the coupling agent was determined by FT-IR spectroscopy assuming that a covalent bond was established, avoiding the adverse effect of the poor compatibility at the interface for this kind of composites.