Homide 250 (Diamino diphenyl methane bismaleimide-diamino diphenyl methane copolymer) was used as the BMI details of which are given in ref [2, 6]. The process consisted of BMI being dissolved in distilled water and stirred and Al2 (SO4)3 added gradually along with PVA and stirred. The thick solution formed was then applied on glass slides and heated at 100 and 150 o C to form a solid coating. XRD (Proto, Canada) with Cu-Kα (1.54 Å) was used and the crystallites size(D) were determined by Scherer equation (D =k λ/β cos ϴ where β is the FWHM and k(0.9) is the shape factor.