Publication: Nişasta üzerinde stiren, akrilik asit ve türevlerinin graft kopolimerizasyonu
Abstract
Bu çalışmada , nişasta ve jelatinize nişasta üzerine seryum (IV) amonyum nitrat ve mangan (III) asetat -pirofosfat başlatıcı sistemleri kullanılarak stiren ve akrilik asitin graft kopolimerizasyonu incelenmiştir.Deneyler, değişik nişasta miktarları , farklı monomer konsantrasyonları kullanılarak, üç farklı reaksiyon sıcaklığında, asitli ve asitsiz ortamlarda , normal koşullarda ve azot atmosferinde yapılmıştır. İlk olarak nişasta ve jelatinize nişasta üzerine stirenin graft kopolimerizasyonu , seryum(IV) amonyum nitrat başlatıcı sistemi kullanılarak 45 oC , 60 oC ve 80 oC sıcaklıklarda , geniş bir monomer aralığında (0,25 M- 1,5 M) çalışılmıştır. Normal koşullarda ve azot atmosferi altında, asitli ve asitsiz ortamlarda yapılan deneylerde istenilen sonuçlar elde edilmediğinden , deneyler aynı şartlar uygulanarak , ancak başlatıcı olarak Mangan (III) asetat- pirofosfat kullanılarak tekrar edilmiştir.Ancak düşük graftlama veriminde bir değişiklik gözlenmemiştir. Bu nedenle nişasta üzerine akrilik asitin graft kopolimerizasyonu denenmiştir. Nişastanın akrilik asitle graft kopolimerizasyonunda , seryum (IV) amonyum nitrat başlatıcı sistemi kullanılarak , geniş bir monomer aralığında (0,5 M- 2,5 M) 30 oC, 45 oC ve 60 oC sıcaklıklarda yapılan deneylerden graftlama veriminin monomerin konsantrasyonuyla arttığı ancak belli bir konsantrasyondan sonra azaldığı görülmüştür. Deneyler jelatinize nişasta ile tekrarlandığında aynı sonuçlar bulunmuştur. Elde edilen ürünlerin hidrojel özelliği gösterebileceği dikkate alınarak, su tutma özellikleri incelenmiştir. Su tutma kapasitesi deneyleri , destile su ve % 1 lik NaOH çözeltileri içinde gerçekleştirilmiştir. Monomer konsantrasyonunun artmasıyla örneklerin su tutma kapasitelerinin azaldığı bulunmuştur.
GRAFT COPOLYMERIZATION OF STYRENE AND ACRYLIC ACID ONTO STARCH In this research, using ceric ammonium nitrate and mangane acetate- pyrophosphate initiator systems, graft copolymerization of styrene and acrylic acid onto starch and gelatinized starch were investigated. Experiments were carried out in acidic and non-acidic medium, under nitrogen atmosphere and at four different reaction temperatures. Experiments are carried out different amount of starch and monomer concentration were used in these experiments. Graft copolymerization of styrene onto starch and gelatinized starch were studied at three reaction temperatures (45oC, 60oC, 80oC) using Ce(IV) ammonium nitrate initiator system and wide range of monomer concentration (0.25 M-1.5 M). Experiments has been done open and nitrogen atmosphere , both acidic and non- acidic medium and were not able to obtain desirable results, so that experiments were repeated under the same conditions using Mn(III)- pyrophosphate initiator system but decreasing grafting percentage was optained. Graft copolymerization of acrylic acid onto starch with acrylic acid were studied at three reaction temperatures (30oC, 45oC, 60oC) using Ce(IV) ammonium nitrate initiator system. It was observed that grafting percentage increased at a certain monomer concentration and than decreased. Graft copolymerization of gelatinized starch with acrylic acid gave, same simular results. Additionally, water retention properties of grafted products were investigated. Water retention capacity experiments were carried out into distilled water and %1 NaOH solution. It was found that water retention capacity of samples decreased with increasing of monomer concentrations. The retention capasity measuresual with time in some experiments.
GRAFT COPOLYMERIZATION OF STYRENE AND ACRYLIC ACID ONTO STARCH In this research, using ceric ammonium nitrate and mangane acetate- pyrophosphate initiator systems, graft copolymerization of styrene and acrylic acid onto starch and gelatinized starch were investigated. Experiments were carried out in acidic and non-acidic medium, under nitrogen atmosphere and at four different reaction temperatures. Experiments are carried out different amount of starch and monomer concentration were used in these experiments. Graft copolymerization of styrene onto starch and gelatinized starch were studied at three reaction temperatures (45oC, 60oC, 80oC) using Ce(IV) ammonium nitrate initiator system and wide range of monomer concentration (0.25 M-1.5 M). Experiments has been done open and nitrogen atmosphere , both acidic and non- acidic medium and were not able to obtain desirable results, so that experiments were repeated under the same conditions using Mn(III)- pyrophosphate initiator system but decreasing grafting percentage was optained. Graft copolymerization of acrylic acid onto starch with acrylic acid were studied at three reaction temperatures (30oC, 45oC, 60oC) using Ce(IV) ammonium nitrate initiator system. It was observed that grafting percentage increased at a certain monomer concentration and than decreased. Graft copolymerization of gelatinized starch with acrylic acid gave, same simular results. Additionally, water retention properties of grafted products were investigated. Water retention capacity experiments were carried out into distilled water and %1 NaOH solution. It was found that water retention capacity of samples decreased with increasing of monomer concentrations. The retention capasity measuresual with time in some experiments.