Fabrication of short glass fiber reinforced phenol-formaldehyde-lignin and polyurethane-based composite foam: mechanical, friability, and shape memory studies

摘要

In this research effort, phenol-formalde-hyde-lignin (PFL) resin was prepared using phenol, formaldehyde, and lignin via a simple approach. The PFL-polyurethane (PFL-PU) was prepared using PU pre-polymer and PFL resin. The blend components were then foamed via addition of Tween 80 surfactant and n-pentane as the blowing agent. Short glass fiber was reinforced in the blend sample to attain high performance composite foams. The composite foams were characterized for structure, morphology, stress-strain behavior, friability tests, and shape memory characteristics. Scanning electron microscopy showed a layered, porous, and distorted hexagonal shaped foam structure. The cell size ranges from 10 to 20 mu m for PFL-PU-short glass fiber (SGF) Foam with 10-20 wt.% fiber loading. PFL-PU Foam had compression strength and strain of 48.3 MPa and 48.2%. The PFL-PUSGF 1-20 Foam showed increase in strength from 55.1 to 101.7 MPa and decrease in strain from 57.8% to 35.8% due to filler addition. At temperature above T-g (130 degrees C), the strain was increased up to 45.11%. The shape fixity was improved up to the addition of 10 wt.% filler where the value of 92.1% was achieved with shape recovery of 95%.