Synthesis and thermal characterization of xylan-graft-polyacrylonitrile


Ünlü C. H. , Öztekin N., Atici O.

CARBOHYDRATE POLYMERS, cilt.90, ss.1120-1126, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 90 Konu: 2
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1016/j.carbpol.2012.06.053
  • Dergi Adı: CARBOHYDRATE POLYMERS
  • Sayfa Sayıları: ss.1120-1126

Özet

In this study emulsion polymerization of acrylonitrile using xylan from agricultural waste material (corn cob) and cerium ammonium nitrate was investigated in terms of catalyst acid. Stock ceric solutions were prepared using either nitric or perchloric acid as catalyst. Optimum conditions were determined using different parameters such as reaction time, temperature, and component concentrations. Nitric acid catalyzed reactions resulted in maximum conversion ratio (96%) at 50 degrees C, 1 h where ceric ion, acrylonitrile, xylan, and catalyst concentrations were 21.7 mmol l(-1), 0.5 mol l(-1), 0.2% (w/v), and 0.1 mol l(-1), respectively. However, 83% conversion was obtained with perchloric acid catalysis at 27 degrees C, 1 h where concentrations were 5.4 mmol l(-1), 0.8 mol l(-1), 0.5% (w/v), and 0.2 mol l(-1), respectively. Copolymer synthesis using perchloric acid was realized at milder conditions than using nitric acid. Thermal analyses of obtained polymers were conducted to characterize copolymers. Results showed that calculated activation energy, maximum degradation temperature, and heat of thermal decomposition changed relying mainly on molecular weight. (C) 2012 Elsevier Ltd. All rights reserved.