Preparation And Properties Of Itaconate Based Polymers And Their Composites

Rubbers are important and indispensable polymer materials.With the fast developing of economics,more and more novel functional applications desire large consumption of rubbers except those conventional rubber consumption fields.With excellent overall performance,nature rubber was widely applied in many fields.However,hevea brasiliensis can just planted in some certain areas and it’s very difficult to increase the output of nature rubber for now.Besides,synthetic rubbers highly depend on non-renewable fossil resources,which made rubber industry possess many problems.Design and preparation of high performance bio-based materials from biomass or bio-based chemicals are with great significance.Itaconic acid,which can large scale produced by the fermentation of sugarcane starch and corn starch,has been already widely used in materials modification and plastic products.The output of itaconic acid has exceeded 100 kt/year for recently years.The stable biomass supplement and proven technique of fermentation provide important premise for constructing new polymers.Previously,our research group has successfully synthesized bio-based elastomer from itaconic acid,isoamyl alcohol,and isoprene.The bio-based elastomer possesses good overall properties and potential for wide use in engineering areas.In the first part of this thesis,we synthesized dimethyl itaconate/isoprene copolymer and carried on the research of use the new copolymer as shape-memory materials.In the second part of this thesis,we synthesized bio-based elastomer(PDII)from itaconic acid,n-butyl alcohol,and isoprene.Molybdenum disulfide(MoS2)was introduced to prepare PDII/MoS2 composites and the properties of PDII/MoS2 composites are studied.In the third part of this thesis,carboxylic group functionalized PDII elastomer(XPDII)was synthesized from itaconic acid,n-butyl alcohol,isoprene and methacrylic acid.And XPDII/GO composites were prepared and studied.Details of each part are listed as following:(1)As the glass transition temperatures of dimethyl itaconate/isoprene copolymer are higher than conventional elastomers,we tried to use the copolymer as shape-memory materials.First,dimethyl itaconate/isoprene copolymers with different dimethyl itaconate/isoprene ratios were synthesized.With the increase of isoprene contents,glass transition temperatures of dimethyl itaconate/isoprene copolymers decreased.The structures of dimethyl itaconate/isoprene copolymers were confirmed by FTIR and 1H NMR spectra.Polyisoprene segements are mainly added by 1,4-addition.Crosslinking properties of 70/30 and 50/50 copolymers are studied and 50/50 copolymer was used to carry on the research as shape-memory properties.(2)High molecular weight,low glass transition temperature and bio-based elastomer(PDII)was synthesized by di-butyl itaconate and isoprene.Molybdenum disulfide(MoS2)was added in PDII elastomers to prepare PDII/MoS2 composites.In order to enhance the interface interaction between PDII and MoS2,MoS2 was modified by cetyl trimethyl ammonium bromide(CTAB),polyethylene glycol(PEG),silane coupling agent(KH570)and stearic acid(SA)and KH570 provided superior properties.Besides,carbon black was further introduced to prepare PDII/CB/KH570-MoS2 composite.PDII/CB/KH570-MoS2 composite had higher mechanical and thermal resistance properties than PDII/CB.The friction coefficient of PDII/CB/KH570-MoS2 was also lower than PDII/CB,which made PDII/CB/KH570-MoS2 ideal candidate for dynamical sealing material in engineering applications.(3)Functionalized PDII elastomer(XPDII)with carboxyl groups was synthesized by the copolymerization of di-n-butyl itaconate,isoprene and methylacrylic acid.XPDII can form covalent bonds between XPDII macromolecular chains and grapheme oxide(GO).GO has better dispersion in XPDII matrix than PDII.High performance XPDII/GO composites were prepared in this part.