Application Of Functionalized Polyvinyl Chloride In Organic Synthesis And Colorimetric Analysis

Polyvinyl chloride(PVC)is one of the most widely used resins in the world,and its functionalization has drawn much attention.The modification of PVC can be divided into physical modification and chemical modification.Among them,physical modification is mainly mixed with additives to improve its performance,and chemical modification is to improve the performance of polyvinyl chloride or to prepare new materials through the chemical reactions.There are many works on the application of functional polyvinyl chloride in catalysis,organic synthesis,materials.The existence of C-Cl bonds in polyvinyl chloride enables it easy to react with many molecules to introduce suitable groups to support catalysts.This kind of heterogeneous catalyst can not only solve the drawbacks such as recovery and recycling of catalyst,but also can adjust the catalytic activity by the introduced ligands,so that it can exert excellent catalytic performance in various reactions.In another work,by adding a specific color-developing substance on the PVC film,can be used as a detection material with colorimetric performance.The use of polyvinyl chloride is also beneficial to reduce the cost and make the operation simple and convenient.Therefore,this dissertation mainly divide into three parts:1.Using polyvinyl chloride as the supportive materials,polyvinyl chloride was modified by treatment of N-methylimidazole(MIM)to synthesis of supportive material(PVC-MIM)with a large number of nitrogen heterocycles,and then it was treated with Pd salt to afford an efficient heterogeneous catalyst PVC-NHC-Pd.Various characterizations of this catalyst were subsequently performed.Finally,formic acid was used as the hydrogen source for the semi-hydrogenation reaction of alkynes.Experimental results showed that the catalyst has the merits of high catalytic activity in the semi-hydrogenation reaction of diphenylacetylenes,good stereoselectivity,and substrate applicability.2.In order to investigate the generality of this catalyst,we tried to use this catalyst for the reductive formylation of nitroarenes by using formic acid as both hydrogen source and carbonyl source.Experimental results show that the catalyst has good catalytic activity and catalytic performance.3.Add dioctyl phthalate as a plasticizer to the tetrahydrofuran solution of PVC,and then add piperidine to prepare a PVC detection film.The detection film displays a unique color through the interaction of piperidine with TNT.Through the relationship between color chroma and TNT concentration,the corresponding colorimetric card was prepared for subsequent use.At the same time,by using a smartphone to take a picture of the color-developing film,which was furtherly analyzed by professional software,the concentration of TNT dripped can be obtained directly.Starting from the cheap and easily available PVC,a novel PVC-supported carbene palladium catalyst was fabricated through the functionalization of N-methylimidazole.With formic acid as hydrogen source and carbonyl source,the catalyst can effectively catalyze the semi-hydrogenation of alkynes and the reductive formylation of aromatic nitro compounds.A low-cost PVC/piperidine composite membrane was fabricated by PVC and piperidine,which can simply and conveniently detect the concentration of explosive TNT.