Abstract: In this work, termite-resistant gas pipes were manufactured by using four types of polyethylene (PE) and two types of polypropylene (PP) and their resistance to termite damage was investigated intensively. Effects of coextrusion technology and adhesion modifiers on peel strength of PP protection layer were also evaluated. The results indicated that damage level of the pipes by termites reached 3 when being prepared by using PE, but it could reach 1 by using PP protection layer with a shore hardness of 73.5. The step-by-step coextrusion technology was considered as an optimum choice for the preparation of termite-resistant gas pipes. The peel strength of the protection layer increased with an increase of the content of the adhesion modifier, and it reached an optimum value when more than 3 phr of adhesion modifier was added into the protection layer.

Key words: polyethylene, polypropylene, termite resistance, step-by-step coextrusion technology, peel strength