Thermophysical and fire properties of vakka natural fiber reinforced polyester composites.

Partially biodegradable green composites have been made by incorporating vakka fibers as reinforcement in the polyester matrix. The influence of fiber content and temperature on thermal conductivity, specific heat and thermal diffusivity of composites was investigated. The transverse thermal conductivity of unidirectional composites was investigated experimentally by a guarded heat flow meter method. It was observed that the thermal conductivity of composite decreased with increase in fiber content and at maximum volume fraction of fiber, thermal conductivity of the composites was found to be 0.179 W/m · K. Moreover, the experimental results of thermal conductivity as a function of volume fraction were compared with theoretical model. Thermal conductivity and specific heat capacity of the composite increased with temperature. The lowest thermal diffusivity of 0.55 × 10−7 m2/s for the composite was achieved at a temperature of 120℃. Fire behavior of vakka fiber composite and virgin polyester was investigated using cone calorimeter. The composite ignite earlier and emit lower values of heat release rate and peak heat release rate, when compared to neat polyester resin. Theoretical models were used to predict time to flashover and ignition temperature using cone calorimeter test results as input data. [ABSTRACT FROM AUTHOR]