Preparation And Properties Of Perfluorocyclobutyl Ether Resins Based On Eugenol

Polymer material has become an indispensable material in national economic construction and People’s Daily life because of its advantages that inorganic and metal materials can not be replaced.At present,most polymer materials are derived from petroleum-based resources.Considering the rapid consumption of petroleum resources and environmental pollution,it is of great practical significance to develop high-performance polymer materials based on biomass materials to replace petroleum-based polymer materials.Among biomass materials,eugenol,as an aromatic vegetable oil,is an ideal candidate for the preparation of high-performance bio-based polymer materials due to its wide availability,environmental friendliness and its structure containing rigid benzene ring,active hydroxyl group and allyl group.Perfluorocyclobutyl aryl ether(PFCB)polymer is a kind of special fluopolymer formed by the[2π+2π]thermocyclization reaction of trifluorovinyl ether(TFVE)compounds.It has excellent thermal stability,low dielectric properties,chemical resistance and optical transparency.In order to prepare high-performance bio-based polymer materials,in this paper,based on the biological eugenol as raw material,the introduction of trifluorovinyl ether group on the basis of siloxane coupling,through the thermocyclization reaction to prepare eugenol-based PFCB polymer with excellent thermal stability and adjustable mechanical properties,and the method of further improving the performance of linear PFCB polymer by using methoxyl group on the structure of eugenol was explored.This work provides a strategy to design of high-performance bio-based polymer materials by using eugenol and trifluorovinyl ether.The main research contents are as follows:(1)with eugenol as raw material,using 1,1,3,3-tetramethyldisiloxane(TMDS),1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane(TMDPS)and 2,4,6,8-tetramethyl-cyclotetrasiloxane(TMTOS)as coupling agents,through fluoroalkylation reaction,hydrosilylation reaction and elimination reaction,three eugenol-based TFVE monomers ES-TFVE,EPS-TFVE and EOS-TFVE were prepared,and the effects of different dewatering methods and different catalysts on the yield of products were studied.The results showed that the xylene azeotrope is the best dewatering methods,and the catalytic activity of Karstedt catalyst is better than that of Speier catalyst.(2)Using ES-TFVE,EPS-TFVE and EOS-TFVE as materials,three eugenol-based PFCB polymers were prepared by[2π+2π]thermocyclization reaction.The properties of the cured samples were studied.The results showed that the cured samples of EOS-TFVE,EOS-PFCB exhibit rigid solid state at room temperature while the cured products of ES-TFVE and EPS-TFVE are viscous liquids.Co-curing EOS-TFVE with ES-TFVE(EPS-TFVE),the co-cured samples EOS/ES-PFCB 50/50 and EOS/EPS-PFCB 50/50 showed rubber-like elastic behaviors and maintain excellent thermostability,which has the potential to be used as high temperature elastomers.In addition,all cured samples showed good dielectric properties,transparency and hydrophobicity due to the introduction of PFCB groups.(3)Taking the methoxy group,which is easily ignored in the structural modification,as the reaction site,the structure of bifunctive monomer EPS-TFVE was improved by the Piers-Rubinsztajn reaction,and linear polysiloxane EPS-ES-TFVE and EPS-PS-TFVE as well as four-functional groups TFVE monomer EPS-FS-TFVE were prepared.Then,the corresponding PFCB polymer was prepared by the[2π+2π]thermocyclization reaction,and the effects of the introduced structures on the properties of the cured samples were investigated.The results showed that the glass transition temperature(T_g)and thermostability of all cured samples were improved due to the increase of the cross-linking degree of cured samples.Due to the introduction of flexible siloxane segments,the T_gof the cured samples of EPS-ES-TFVE and EPS-PS-TFVE was lower than room temperature and showed higher breaking elongation.The cured samples of EPS-FS-TFVE showed higher thermostability,low dielectric properties and transparency due to the increased proportion of PFCB group in the system.