Perfluoromethacrylate-styrene statistical copolymers synthesized in CO2-expanded monomers


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Cengiz U. , Erbil H. Y.

COLLOID AND POLYMER SCIENCE, cilt.292, ss.2207-2215, 2014 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 292 Konu: 9
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1007/s00396-014-3250-8
  • Dergi Adı: COLLOID AND POLYMER SCIENCE
  • Sayfa Sayıları: ss.2207-2215

Özet

Statistical copolymers of perfluoroalkyl ethyl methacrylate (Zonyl-TM) and styrene (S) were synthesized in CO2-expanded monomer medium at a low initial pressure of 25 MPa. Different Zonyl-TM/S feed ratios were used during copolymerizations, and it was determined that the increase in the Zonyl-TM content and decrease of the CO2 amount in the comonomer feed resulted in a decrease of the molecular weights of copolymers due to earlier precipitation of copolymers giving shorter chains. The cloudy CO2-expanded liquid monomer phase was found to be the main loci of copolymerization. In addition, the increase in the Zonyl-TM feed ratio resulted in an increase in the critical degree of the polymerization time (J (crit)) as the time when the copolymer chains start to precipitate. The higher the Zonyl-TM content used in the feed, the higher the J (crit) time and the lower the weight-average molecular weight (M (w)) of the copolymer obtained. Thermal analysis results of the copolymer indicated that the copolymers are stable up to 387-403 A degrees C.

Statistical copolymers of perfluoroalkyl ethyl methacrylate (Zonyl-TM) and styrene (S) were synthesized in CO2-expanded monomer medium at a low initial pressure of 25 MPa. Different Zonyl-TM/S feed ratios were used during copolymerizations, and it was determined that the increase in the Zonyl-TM content and decrease of the CO2 amount in the comonomer feed resulted in a decrease of the molecular weights of copolymers due to earlier precipitation of copolymers giving shorter chains. The cloudy CO2-expanded liquid monomer phase was found to be the main loci of copolymerization. In addition, the increase in the Zonyl-TM feed ratio resulted in an increase in the critical degree of the polymerization time (J crit) as the time when the copolymer chains start to precipitate. The higher the Zonyl-TM content used in the feed, the higher the J crit time and the lower the weight-average molecular weight (M w) of the copolymer obtained. Thermal analysis results of the copolymer indicated that the copolymers are stable up to 387–403 °C.