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Polyacrolein with microspherical structure obtained by radiation-initiation and base catalysis

1990-3
Usanmaz, Ali
Dogan, Recep Dursun
Acrolein was polymerized by radiation and base catalyzed condensation. Radiation polymerization was carried in bulk form under vacuum and air atmosphere at several temperatures. The conversion reached close to 100%, and polymers were free flowing white powders up to 5% conversion at −15°C, up to 80% at higher temperatures and up to 10% in air atmosphere polymerization. Radiation polymerization from aqueous solutions of various pH and from acetone solutions gave white powder polymers with limiting conversions ranging from 10 to 18% depending on the solution type or pH. The conversion at pH between 1, 5 to 8 gave minimum pH of 5 to 6. The base catalyzed polymerization at pH of 9 to 12 gave white powdered polymers changing to a yellowish colour with increase of pH. The limiting conversion was about 14%. The nature of repeating units in the polymer chains was studied by IR and thermogravimetry. The polymers contained different repeating units randomly, and the aldehyde content was higher for radiation polymerization than base catalyzed polymerization. A scanning electron microscope investigation showed the powder polymers to have microspherical structures of various size depending on polymerization conditions.