Studies on synthesis and characterization of hydroxyl-terminated polydimethylsiloxane-modified epoxy bismaleimide matrices

Abstract

This work reports the development of hydroxyl-terminated polydimethylsiloxane (HTPDMS)-toughened tetraglycidyl diaminodiphenyl methane (TGDDM) epoxy matrix systems. The siliconized epoxy systems were further modified with various percentages of (5, 10 and 15 wt%) 10-phenyl-phenonoxaphosphine-3,8-di(2-hydroxy-3-( p-male-imidobenzoyloxy)propyl) ester-10-oxide (EPBMI) and cured by diaminodiphenyl sulfone. Thermal, mechanical and morphological properties of the prepared samples were studied by standard methods. In comparison with the unmodified epoxy resin, HTPDMS-incorporated TGDDM resin showed increased impact strength with a reduction in tensile strength, flexural strength and glass transition temperature ( Tg). But in the case of bismaleimide (BMI; EPBMI)-incorporated epoxy resin, tensile strength, flexural strength and Tg showed an increasing trend. However, the introduction of both siloxane and BMI into epoxy influences the mechanical and thermal properties according to their percentage content. The morphology of the silconized and the BMI-modified epoxy systems was also studied by scanning electron microscopy.