Preparation And Performance Of Functionalized Syndiotactic Polystyrene/Activated Carbon Composites

Polymers/inorganics composites have many excellent properties in electricity,thermology,mechanism,electromagnetics,biology,etc.Polymers/inorganics composites have become the research focus in material science.Combining advantages of polymers and inorganics,the catalistic performance of heterogeneous catalysts can be further improved when using polymers/inorganics composite as the supporter.In this thesis,polymers/inorganics composites were prepared by activated carbon compounding with amino-functionalized syndiotactic polystyrene or hydroxyl-amino-functionalized syndiotactic polystyrene.Palladium was loading on the composite supporter.The influence of composite method and polymer structure on the microscopic morphology of composite supporters and palladium was investigated,as well as the catalystic performance.Functionalized syndiotactic polystyrene/activated carbon composites and palladium nanocatalysts with high catalytic performance were obtained.1.The sPS-NMe₂/AC composite supporters were prepared by compounding amino-functionalized syndiotactic polystyrene?sPS-NMe₂?and activated carbon?AC?in three different ways,i.e.,dropping methanol into a suspension of s PS-NMe₂ and AC?MP?,volatilizing solvent of a suspension of sPS-NMe₂ and AC?MV?,and polymerization of p-N,N-dimethylaminostyrene in the presence of AC?DP?.The good combination between sPS-NMe₂ and AC was obtained using MV method on the base of SEM and TEM analysis.The surface of AC was uniformly covered by sPS-NMe₂ when the mass ratio of s PS-NMe₂ to AC was equal or more than 1/3.The uniform combining structure ensures the fast adsorption of PdCl₂,and the Pd@sPS-NMe₂/AC catalyst with 3 nm Pd nanoparticles dispersing evenly was obtained after the reduction of PdCl₂.Pd@sPS-NMe₂/AC catalyst showed excellent catalytic performance and reusability in the coupling reaction of hydrogen-borrowing reactions and Suzuki,Heck and Sonogashira C-C coupling reactions.2.The St-NMe₂-IP copolymers with controllable isoprene?IP?content was prepared by the copolymerization of p-N,N-dimethylaminostyrene with IP catalyzed by?C₅Me₄SiMe₃?Sc?CH₂C₆H₄NMe₂-o?₂.It is found the St-NMe₂-IP copolymers were random copolymers with IP isolatedly inserted into sPS-NMe₂ by NMR,DSC and GPC analysis.Hydroxyl-amino-functionalized syndiotactic polystyrene?sPS-NMe₂-IP-OH?was synthesized after hydroxylation of the double bond in St-NMe₂-IP.sPS-NMe₂-IP-OH was compounded with AC by MV method.The SEM and TEM analysis showed that the surface of AC was uniformly covered by s PS-NMe₂-IP-OH with small thickness.The introduction of hydroxyl groups into amino-functionalized syndiotactic polystyrene,the sPS-NMe₂-IP-OH polymers had better combination ability with AC.The Pd@sPS-NMe₂-IP-OH/AC catalyst prepared with sPS-NMe₂-IP-OH/AC supporter has better catalytic performance.The catalytic activity of differentcatalystsisPd@sPS-NMe₂-IP-OH/AC>Pd@sPS-NMe₂/AC>Pd@sPS-NMe₂>Pd@AC.