Effect of structure of nadimides on properties of glass fibre reinforced composites*

Abstract

The paper describes fabrication of glass fibre reinforced laminates based on three structurally different nadimide oligomers containing phosphine oxide in the backbone and a low molecular weight low viscosity allyl nadicimide resin. Fabrication of laminates was done using methyl ethyl ketone solvent. Interlaminar shear strength and flexural strength of laminates, containing 0.67-0.5 volume fraction of fibres, depended on the structure of the resin and was found to be higher in laminates based on resins with higher polarity and having phosphine oxide in backbone. Properties of composites based on blends of these resins could be predicted on the basis of rule of mixtures. A marginal synergism was observed in one case.

<i>T</i>_g<i> </i>was in the range of 230-270°C and was found to increase marginally in blends. Effect of oven aging and boiling water treatment on the properties of composites is also reported.