| Cured unsaturated polyester resins have excellent mechanical properties,electrical insulation properties and corrosion resistance.They can be used alone in many fields,and They can be blended with fibers or fillers to produce cured unsaturated polyester composites,which have been widely used in the fields,including industry,agriculture,transportation,construction and defense industries.However,the cured unsaturated polyester resin is usuallyt prepuced using volatile and toxic styrene as an active monomer and a curing agent,which has been causing great concern over human healthy and environment.In order to solve this issue,based on the o-unsaturated polyester UPE substrate for the curing molding in this study,two kinds of low volatility functional monomers,acrylated epoxy soybean oil?HAESO?and urethane acrylate?HEA-MDI?were synthesized.And 1,6-hexanediol diacrylate?HDDA?from the existing products was selected as the cross-linking component to replace styrene.A series of styrene-free unsaturated polyester resins with different compositions were prepared.The viscosity characteristics,static mechanical properties,dynamic mechanical properties and curing kinetics of non-styrene unsaturated polyester resins were analyzed.It has laid a solid theoretical and experimental foundation for the use of non-styrene unsaturated polyester resin.The main contents and results of the thesis are as follow:?1?Firstly,acrylated epoxy soybean oil?HAESO?was synthesized by using environment-tally friendly epoxy soybean oil?ESO?,hydroxyethyl acrylate?HEA?and phthalic anhydride?PAH?.And then,a series of UPE/HAESO/HDDA resins were prepared by using HAESO,HDDA and unsaturated polyester?UPE?.The viscosity,static mechanical properties and dynamic mechanical properties of the prepared UPE/HAESO/HDDA resin systems were investigated.When the content of HAESO/HDDA remained unchanged,the viscosity of the resin system increased with the increase of HAESO content.When the content of HAESO/HDDA is 55 wt%,the tensile strength,flexural strength,impact strength and elongation at break of the resin system have no obvious change trend;When the content of HAESO/HDDA are 50 wt%and 45 wt%,respectively,the tensile strength and flexural strength of these resins system decrease with the increase of HAESO content,and the impact strength and elongation at break increase with the increase of HAESO content.Compared with the UPE/HDDA resin,the impact strength and elongation at break of UPE/HAESO/HDDA resin has been greatly improved with the addition of HAESO.The impact strength is above 10.0 kJ/m2,the elongation at break is above 4.6%,it has better performance than the UPE/St resin,but it has lower tensile strength,flexural strength and glass transition temperature.And when the mass ratio of UPE/HAESO/HDDA is 45/10/40,the viscosity of the resin system is 3186 mPa·s,the mechanical properties of the obtained cured resin are better relatively.The tensile strength,flexural strength,impact strength,tensile elongation at break and glass transition temperature are 22.5 MPa,27.5 MPa,20.5 kJ/m2,6.2%and 58?.?2?Urethane acrylate?HEA-MDI?was synthesized by using diphenylmethane diisocyanate?MDI?and hydroxyethyl acrylate?HEA?.And then,a series of UPE/HEA-MDI/HDDA resins were prepared by using HEA-MDI,HDDA and unsaturated polyester?UPE?.The viscosity,heat distortion temperature,static mechanical properties and dynamic mechanical properties of the prepared UPE/HEA-MDI/HDDA resin systems were investigated.When the HAESO/HDDA content is constant,the viscosity,heat distortion temperature,tensile strength,flexural strength and glass transition temperature of UPE/HEA-MDI/HDDA resin increase with the increase of HEA-MDI content,the impact strength and elongation at break of UPE/HEA-MDI/HDDA resin have no obvious change trend,but the impact strength is above10.0 kJ/m2,the elongation at break is above 4.6%.it had comparable viscosity,heat distortion temperature,tensile strength with UPE/St resin and its impact strength and elongation at break has better performance than UPE/St resin,but the flexural strength and glass transition temperature Tg of UPE/HEA-MDI/HDDA resins has a small gap.And,when the mass ratio of UPE/HEA-MDI/HDDA is 50/10/40,the viscosity of the resin system is 1913 mPa·s.The tensile strength,impact strength,tensile elongation at break and heat distortion temperature of the cured resin are 38.9 MPa,10.7 k J/m2,4.8%and 45.8°C,respectively.The flexural strength and glass transition temperature were 43.0 MPa and 63°C,respectively,it slightly lower than that of the conventional UPE/St resin.?3?The curing process of resin with UPE/HEA-MDI/HDDA mass ratio of 50/10/40 were studied.It included the viscosity,gel time,conversion ratio,volatile component content and some other characteristics.At the same time,the curing reaction kinetics of styrene-free unsaturated polyester resin was studied by DSC.The research shows that the curing of unsaturated polyester resin is mainly the reaction between carbon and carbon double bonds.With the increase of initiator content,the gel time of resin system decreased gradually.Compared toUPE/St resin,the curing volatile component content of the resin is only 0.19wt%.The apparent activation energy of curing reaction was 42.48 kJ·mol-1,the collision factor A was 5.523?105,the order of reaction was 0.880.In addition,the characteristic curing temperature of the resin system was obtained,with which the gel temperature was 51.5?,the curing temperature was 57.8?and the post-curing temperature was 62.8?. |
PDF Full Text Request