Modification of polyester resin based composites induced by seawater absorption

This research is a study on seawater absorption ability and on mechanical performance (before and after immersion in seawater) of two composites that basically differ for what concerns the polyester resin (isophthalic or orthophthalic) employed in boats manufacture. Experimental tests, carried out on the two resins, evidenced that they differ for what concerns their structural organization, water diffusion coefficient, thermal stability, wet ability toward glass fibre beside commercial cost. Isophthalic resin resulted well bonded to glass fibres so that seawater absorption resistance was higher compared with that of orthophthalic one. As a consequence, the composite containing isophthalic resin showed higher flexural stiffness and strength, as well as higher shear strength.