Why does Kevlar decompose, while Nomex does not, when treated with aqueous chlorine solutions?


Akdag A., Kocer H. B., Worley S. D., Broughton R. M., Webb T. R., Bray T. H.

JOURNAL OF PHYSICAL CHEMISTRY B, cilt.111, sa.20, ss.5581-5586, 2007 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 111 Sayı: 20
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1021/jp070586c
  • Dergi Adı: JOURNAL OF PHYSICAL CHEMISTRY B
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.5581-5586
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Kevlar and Nomex are high-performance polymers which have wide varieties of applications in daily life. Recently, they have been proposed to be biocidal materials when reacted with household bleach (sodium hypochlorite solution) because they contain amide moieties which can be chlorinated to generate biocidal N-halamine functional groups. Although Nomex can be chlorinated without any significant decomposition, Kevlar decomposes under the same chlorination conditions. In this study, two mimics for each of the polymers were synthesized to simulate the carboxylate and diaminophenylene components of the materials. It was found that the p-diaminophenylene component of the Kevlar mimic is oxidized to a quinone-type structure upon treatment with hypochlorous acid, which then decomposes. However, such a mechanism for the Nomex mimic is not possible. In this paper, based upon these observations, a plausible answer will be provided to the title question.