Hybrid composites of jute and man-made cellulose fibers with polypropylene by injection moulding

A number of hybrid composites was made with jute, mercerised jute, and high tenacity man-made cellulose tyre cord yarn Cordenka of dissimilar ratios by a pultrusion process and subsequent injection moulding. Composites of jute, mercerised jute, and Cordenka were also made in order to compare the properties. The matrix material was a polypropylene/ethylene block copolymer (PP), and a maleic acid anhydride grafted PP (MAPP) was used as a coupling agent. The overall fiber contain was 25%. Mechanical properties such as tensile and bending strength, tensile and bending modulus, Charpy impact strength, and heat distortion temperature (HDT) were determined. High strength (>70 MPa) and excellent impact properties (>80 kJ/m2) were achieved with pure Cordenka reinforcement. Partial substitution of jute instead of Cordenka leads to enhance stiffness properties of the composite as well as increased heat distortion temperature (HDT) values above 105 °C for all the tested compositions (25%, 50%, 75%, and 100% jute) and for an overall fiber load of 25%. On the other hand, impact strength decreases with increasing jute fraction down to 22 kJ/m2 for pure jute. A good property balance is achieved for a composite with 25 wt.% jute and 75 wt.% Cordenka, maintaining impact strength of 79 kJ/m2. Mercerisation of the jute fibers gave moderate improvements in the composite properties. Very good fiber (both jute and Cordenka) matrix adhesion was observed by SEM.