7.The results show that —C(C=O)CH 3、—CH 2C(=O)CH 2—、—C(=O)O— oxygen containing groups are introduced onto HDPE molecular chain during ultraviolet irradiation in air.
10.Thedetailed XPS analysis indicated that the concentration of carbon in C-C decreased and that of highlyoxidized carbons in C-O, C=O and O=C-O increased with time. The appearance of O=C-O on theSurface of EPDM rubber was a sign in which EPDM rubber became aged. The aging speed decreasedwith time.