Abstract
Jute fibres were pretreated with alkali followed by organotitanate coupling agent. The adsorbed species between 1750-1000 cm(-1) in the subtraction spectra of treated and untreated jute clearly indicate changes in its surface morphology. The unsaturated polyester laminates using treated non-woven jute fabrics exhibited an improvement of similar to 21% in tensile strength and similar to 47% in flexural strength over the untreated jute composites. Sandwich core formulation was made based on unsaturated polyester-urethane hybrid network, calcium carbonate filler, blowing agent and other additives. The adequate strength and dimensional stability of core material could be explained from its SEM morphology in terms of cell orientation and thick cell wall along with adequate intercellular space and also the complete curing of rigid foam as observed in mu DTA in terms of lack of clear melting peaks. The cores are not ignitable and exhibited acceptable fire propagation index (I, 15) after adding optimized levels of fire retardant additives. The sandwich composite panels have been made from jute laminate as a face and hybrid resin foam as a core and characterized for their physico-mechanical properties. The screw withdrawal load of composite panels was found to be >1500 N as against the specified value of 1000 N for wood used for building purpose. Exposure to termite and natural decay against fungus results in <2% weight loss in the samples. The jute composite door shutters using these sandwich composites (3 mm face and 28 mm core) possess comparable properties to wooden door shutters in terms of operational loads and other properties.