¹³C NMR STUDIES ON PHOTOINITIATED CROSSLINKS OF LDPE MODEL COMPOUNDS

Abstract

H- and Y-type crosslinks formed in the benzophenone-photoinitiated crosslinking of various model compounds of low-density polyethylene (LDPE) have been observed and identified for the first time by ¹³C NMR spectroscopy. The quantitative studies show that both H- and Y-links are formed during the photo crosslinking of dodecane and their concentrations are almost the same; the yield of H-links in the crosslinked isooctane is slightly greater than that of Y-links; in contrast, Y-links are dominant for the crosslinked 1-hexene. These results further support the conclusions from the study of photo crosslinking of LDPE and give new experimental evidence for elucidating the mechanism of the photo crosslinking of LDPE.