EFFECT OF ALKALI TREATED WALNUT SHELL (JUGLANSREGIA) ON HIGH PERFORMANCE THERMOSETS. STUDY OF CURING BEHAVIOR, THERMAL AND THERMOMECHANICAL PROPERTIES

摘要

This paper presents a comparative analysis of high performance thermosets based on epoxy (Ep) and diaminodiphenylmethane (DDM) and its blend with DDM based benzoxazine (P-ddm); (Ep/P-ddm) with reinforcement using alkali treated walnut shell (TWN) at 10, 20 and 30 wt% reinforcement. Thermogravimetric (TGA) and x-ray diffraction (XRD) analysis of TWN showed improved thermal stability and crystallinity index. On 30 wt% TWN loading, the storage modulus (G') of Ep/DDM system improved by 42%, while the values of G' and T-g were enhanced by 58% and 30 degrees C, respectively, on the similar loading in Ep/P-ddm, due to the increased number of functional groups on TWN particles. The degradation temperature peak (DTG) of all composites shifted towards the higher temperatures, which confirms the improved thermal stabilities. The prepared composites can be used in solder drip resistance and fire retardant applications as confirmed from limiting oxygen index and DTG peak value.