Study On Copolymerization Of Norbornene And Its Derivatives With SO 2

Sulfur dioxide（SO₂）is a toxic and pungent odorous gas.Its presence is of particular environmental importance as not only is it a potent ’global warming gas’ but in the presence of catalytic nitrogen oxides and water,it is oxidised to sulfuric acid,a component of acid rain.China is the world’s largest SO₂ emissions,so in recent years for SO₂ capture,storage and resource utilization has become a hot research topic.We synthesized poly（norbornene sulfone）via two different polymerization methods.The effect of the different polymerization methods on the copolymerization reaction was analyzed in detail.We introduce side chains from norbornene derivatives into the molecular structures of the poly（norbornene sulfone）s.We believe that poly（norbornene sulfone）s with different side-chain groups may directly disrupt backbone stability by increasing steric demand and altering backbone proton acidity.So we investigated the thermal degradation behavior and solubility of the poly（norbornene sulfone）s with different side chains.Using thermogravimetric analysis to determine the activation energy of degradation of poly（norbornene sulfone）.Differential and integral methods will be discussed and the distinction of the two methods depends on the heating rate:one or more heating rates.The activation energies were obtained using the Coats-Redfern method.Combined with the Flynn-Wall-Ozawa method,KAS method and Kissinger method,the possible thermal degradation mechanism was discussed.1.A novel poly sulfone was easily synthesized by alternating copolymerization of norbornene with SO₂ via free radical copolymerization and coordination copolymerization.Compared with other olefin derivatives,norbornene is a cyclic olefin having a larger steric hindrance,which is easily copolymerized with SO₂,and the obtained poly（norbornene sulfone）s have excellent thermomechanical and optical properties.The effect of the different polymerization methods on the copolymerization reaction was analyzed in detail.The results suggested that different polymerization mechanisms exist in the different polymerization methods and affect the thermal stability and optical properties of the polysulfone.2.We introduce side chains from norbornene derivatives into the molecular structures of the poly（norbornene sulfone）s.A series of poly（norbornene sulfone）s was synthesized through the free radical polymerization of SO₂ and norbornene and derivatives monomers.We believe that poly（norbornene sulfone）s with different side-chain groups may directly disrupt backbone stability by increasing steric demand and altering backbone proton acidity.So we investigated the thermal degradation behavior and solubility of the poly（norbornene sulfone）s with different side chains.The TG and GPC results revealed that bond breaking occurred at different temperatures,because of the different side-chain groups,and three different side-chain groups affect the solubility and stability of the poly（norbornene sulfone）s.A novel photoresist materials based on a poly（olefin sulfone）with different side-chain groups was synthesized and its performance examined.Therefore,we fabricated the copolymers consisting of ternary repeating units,which were prepared using different norbornene derivatives monomers during the copolymerization with SO₂.We used these results to guide polymer design by modulating side-chain group change.We demonstrate control over thermal depolymerization of these polymers.3.A type of functional poly（norbornene sulfone）was synthesized via two differernt polymerization methods.Aiming to understanding the effects of different polymerization methods on poly（olefin sulfone）s and gain further understanding on the kinetics of poly（olefin sulfone）s’s thermal instability.Their detailed thermal degradation behaviors were investigated using thermo-gravimetry,and the resultant kinetics was analyzed in accordance with three kinetic models.The results supported the conclusion that although the poly（norbornene sulfone）s obtained have different activation energy,the thermal degradation kinetics are same and also obey the D1 type.