Flame retardant characteristics of polymerized dopamine hydrochloride coated jute fabric and jute fabric composites Scientific paper

Abstract

In this paper, fire resistance of natural fabrics and their composites were experimentally investigated. Special interest was given to use bio based materials such as lignin, chlorophosphates, levulinic acid and cardanol in order to exploit their capability to be utilized as flame retardants. Dopamine hydro­chloride was polymerized to polydopamine (PDA) and coated to jute fabric surface. Scanning electron microscope (SEM) and thermogravimetric analysis (TGA)/derivative thermogravimetric (DTG) analyses were performed to exam­ine surface morphology and effect of PDA to degradation behaviour of jute fabrics. Real fire behaviour of non-coated and coated fabrics was observed with torch burn test. UL-94 horizontal flame propagation test was also utilized for composite samples. Limiting oxygen index (LOI) testing that measures the minimum amount of oxygen required for combustion, was carried out for assessing the ability of the composite samples for their ability against flam­mability. PDA was seamlessly coated on the surface of the jute fabrics with its surface-active feature without damaging the structure of the fabric as observed in the SEM images. With the support of this coating on the fabric surface, the increase of the decomposition temperature of the material can be clearly seen in TGA/DTG analyses and torch burn test showed the increase in the ignition time. UL-94 horizontal testing resulted in decrease in flame propagation rate of PDA coated composite samples. In addition to this, when the mass loss rates after combustion were examined, it was seen that there is a decrease in mass loss in the coated fabrics. Jute fabrics, a type of natural fabric, can be effi­ciently coated with PDA, and the fire retardant property of the PDA coating on natural fabrics has been clearly demonstrated.