No abstract

High temperature refined thermo-mechanical pulp (MDF fibre) was dried, extracted with neutral organic solvent and reacted with a series of electrophilic reagents (glycidyl methacrylate, maleic anhydride and succinic anhydride). The adducts formed were characterised by infra-red spectroscopy and further reacted in a hot press with methyl methacrylate in the presence of a free radical initiator (benzoyl peroxide). Well conformed board were produced by the process. Samples of these boards were ground to a fine flour, extracted with acetone/toluene to remove poly (methylmethacrylate), PMMA homopolymer and again characterised by infra-red spectroscopy. The spectral evidence suggests that in those boards formed using fibre modified with unsaturated reagents (glycidyl methacrylate and maleic anhydride), some copolymerisation between fibre and PMMA occurs. Where the adduct is saturated (succinic ester), bonding appears to be substantially by physical interaction. Those products formed with the involvement of chemical interaction may have enhanced resistance to deterioration in moist environments.

No abstract

Work to separate the contributions of fatty diamine surfactant (termed a multifunctional additive [MFA]) to property development, from mastication, elastomer–filler interface and crosslink density effects has been carried out. Improvement in mechanical properties resulting from the MFA is dominated by its effect on carbon black dispersion, compared with its effect on crosslink density. Results show that there is a slight improvement in resistance to crack initiation (tensile test) and a substantial improvement in resistance to crack growth (tear strength) as MFA level increases compared with the results for control compounds (extended mixing time compounds). This improvement is attributed to the influence of the MFA on energy dissipation at the rubber–carbon black interface.

Composites of polypropylene (PP) and alkali extracted steam-exploded Acacia mangium wood fiber (AEF) were prepared. The fiber was grafted with maleated polypropylene (MAPP), either Epolene E-43 or Epolene G-3003. Their performance as a compatibilizing agent was compared. Treated fibers were characterized with SEM, ESCA, and FTIR. SEM and ESCA showed the presence of both MAPPs at the fiber surfaces. FTIR spectroscopy was R. M. Taib and Z. A. M. Ishak are affiliated with the School of Materials and Mineral Resources, unable to detect ester links between MAPP and AEF. All mechanical properties were improved with the incorporation of the treated fibers due to improved fiber dispersion and fiber/matrix adhesion as revealed by optical and scanning electron micrographs. As a compatibilizer, Epolene E-43 performed better than E polene G-3003.