Triphenylamine-sensitized photografting of methacrylic acid on low-density polyethylene film

✍ Scribed by H. Kubota; K. Kobayashi; J.F. Ding; Y. Ogiwara

• Book ID: 103074266
• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 258 KB
• Volume: 24
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(88)90081-x

✦ Synopsis

Photografting of methacrylic acid on low-density polyethylene film (thickness = 30pm) in aqueous medium was examined at 40°C and 60°C using triphenylamine (TPA) as sensitizer coated on the film beforehand. Percent grafting and graft efficiency increased with TPA concentration but maxima appeared at a certain concentration. The maxima were not observed for the system using triphenylphosphine in place of TPA, indicating a marked difference in the behaviour. The TPA-initiated photografting was promoted by the presence of acceptors, such as tetracyanoethylene, p-nitrophenol, p-chloranil and maleic anhydride. Based on the study of u.v. spectra, TPA and tetracyanoethylene seemed to form a 1:I complex. The sensitizing effect of TPA on photografting was discussed in terms of photodecomposition of TPA or its complex of TPA with acceptor. In these systems, fragment radicals of the sensitizer produced by the photodecomposition are believed to extract hydrogen atoms from the film substrate to yield polymer radicals capable of initiating grafting.