Cyclopolymerization Of Divinyl Monomer And Synthesis Of Cyclophanealdehyde By Irradiation

The cyclopolymer has a cyclic repeating structure,which makes it have unique properties different from those of ordinary linear polymers.Cyclopolymers have some important applications,such as selective molecular recognition,polymer sequence control,and preparation of chiral responsive polymers,which are difficult to achieve with conventional linear polymers.In order to achieve a very high cyclization efficiency,it is required that during the polymerization process,the rate of cyclization of free radicals in the bifunctional monomer molecules is much greater than the rate of intermolecule propagation.In order to achieve this goal,a dilute solution reaction technique is generally employed to reduce the rate of intermolecular growth;in addition,a suitable divinyl monomer is designed,and in a suitable solvent,the divinyl groups of the monomer adopt a close mutual conformation to increase the speed of the intramolecule cyclopolymerization.As a very important derivative of cyclophane,cyclophanealdehyde has a very broad application prospect.At present,the main methods for synthesizing cyclophanealdehyde are traditional organic synthesis methods such as Reimer-Tiemann reaction,Gattermann-Koch reaction,Vilsmeier reaction,Friedel-Crafts reaction,Duff reaction,etc.These synthetic methods are cumbersome,costly and usually polluted.The irradiation method can generate cyclophanealdehyde by ultraviolet light irradiation,and the cost of green environmental protection is low,and this is what the predecessors have not done,which is of great significance.Irradiation has a unique advantage over chemical synthesis.This work is mainly to study the special ring structure and its ultraviolet irradiation behavior.It is divided into two parts:cyclopolymerization of silane-containing divinyl monomers and synthesis of cyclophanealdehyde by irradiation:(1)We synthesized a difunctional unsaturated monomer,disilane dimethacrylate,by the reaction between 1,2-dichlorotetramethyldisilane and hydroxyethyl methacrylate.The divinyl monomer is subjected to radical cyclization polymerization under dilute solution conditions to afford a linear cyclopolymer.The structure of the cyclopolymer is characterized.(2)We used either 254 nm UV or Co-60 gamma rays to irradiate the[2.2]Paracyclophane.The products after irradiation were studied by1HNMR,13CNMR,GC-MS,etc.,it was found that the product under ultraviolet irradiation was mainly 4-formyl[2.2]paracyclophane and 4,4’-(ethane-1,2-diyl)dibenzaldehyde;the product of Co-60 gamma-irradiation is mainly oligo-Parylene with aldehyde end-groups.