Thermogravimetric analysis of flax, jute, and UHMWPE fibers and their composites with melamine and phenol formaldehyde resins

This article presents the thermal stability of flax, jute and ultrahighmolecular weight polyethylene (UHMWPE) fibers and their composites. Composites are fabricated using a combination of hand layup and compression moulding. Two types of resins namely phenol formaldehyde (PF) and melamine formaldehyde (MF) are considered. Stacking of eight layers of individual fabric was utilised to produce composite panels of 4 mm thickness. Alkali treatment of the flax and jute showed an enhancement in thermal behaviour, whereas UHMWPE fibers sustained the thermal degradation till 474 degrees C. Among the two resin systems, neat MF resin degraded at 278 degrees C with 84% mass loss, whereas PF resin had a final mass loss of 52.54% at 600 degrees C. The thermogravimetric analysis confirmed an increase in thermal stability of the composites considering both resin systems. Density functional theory (DFT) calculation on a small molecular unit of PF, MF, and their complexes with cellulose and molecular unit of UHMWPE indicated that the composites with natural fibers and MF matrix exhibited better thermal stability, while PF resin showed better binding characteristics for composites with UHMWPE fibers. The plausible intermolecular interactions between fibers and the matrix are discussed. The proposed application of the composites is to be used as intermediate wall linings of the furnaces.