چكيده لاتين :
The hybridization of two types of short fibres having different lengths and diameters
offers some advantages compared to each fibre being used alone in a single
polymer matrix. In this study, the polypropylene/kenaf fibre/wood flour hybrid
composites were prepared in an internal mixer. The temperature was 190°C and rotor
speed was 60 rpm. The system was compatibilized by polypropylene grafted maleic
anhydride. Based on dimensional aspects before and after processing, the kenaf as
fibrous filler and wood flour as particulate filler were considered. The weight ratio of lignocellosic
fillers was 40%. Dynamic rheological properties such as storage modulus,
complex viscosity, damping factor were evaluated at 190°C. It was observed that, the
non-linearity region of hybrid composites shifted to lower strains compared to virgin
polypropylene. Due to higher probability of agglomerates formation in the sample containing
40% (by w1) of wood flour, the storage modulus and complex viscosity of this
sample were higher than those of the other samples. A flattened section was observed
in the tan 8 diagram which is attributed to different relaxation processes of composite
and neat PP. The Cole-Cole diagrams of samples showed that the relaxation times
shifted to higher values with the addition of fillers and the longest relaxation times were
related to compos ites with pure wood flour.
