Study On The Synthesis And Characterization Of Transparent ABS Resin By Emulsion In Situ Suspension Polymerization

Due to the suitable mechanical properties, transparent and cheaper,transparent ABS resins have been widely applied in the field of engineeringmaterials. However, preparing transparent ABS resins with excellent mechanicalproperties and transparency is difficulty because new synthesis method and therelationship between the micro-phase construction and the mechanicalproperties have been not reported. This paper reports a novel approach, emulsionin situ suspension polymerization, to synthesize transparent ABS resin.First, we investigated the system is easily to be transferred to thesuspension polymerization state through a coagulating latex technique in theforward direction, and the suspending polymerization process is smoothly withCaCl2 aqueous solution as coagulating agent and HAP/SDBS as dispersion agentwhen forward latex broken was used. The sort and the size of rubber particles donot disturb its distribution when the dosage dos not exceed 20% in the totalcontent of rubber. The mechanical properties of the ABS resin obtained from ourexperiment are as follows: the yield tensile strength is about 35.1-42.2Mpa,impact strength is about 98.2-116.3J/m.. In order to investigate the relationship between its phase construction and thetransparency of T-ABS, we discussed the effect on the transparency of T-ABSresins caused by the sort, the size and the content of rubber particles. Further, wedeveloped an alternative process involving blending or bi-modal rubber particlesfor preparing T-ABS resins. The bases of this method is: (1) rubber particlesin a size less than 80 nm is not disturb the transparency of T-ABS;(2) larger sizeof rubber particles have little effect on the transparency of T-ABS when thesecontent is smaller;(3) the rubber particles distributed uniformly in thecontinuous phase;(4) the transparency of T-ABS resin does not changeobviously by varying the component in continuous phase. The transparency ofT-ABS using SBR70nm/SBR400nm at a proportion of 1:1 and 10% of grossquantity as rubber phase is about 85%;and the transparency exceed 80% usingSBR bi-modal particles(total content of rubber:20%) as rubber phase.The results of the mechanical properties of T-ABS indicated the systemhave not obviously brittle-ductile transition when smaller rubber particles wasused as rubber phase, and the content of rubber is about 9%~10% that the systemappears brittle– ductile transition when SBR bi-modal particles was used asrubber phase. The impact strength of T-ABS increased and the transparencydeclined when the content of the larger rubber particle in SBR bi-modal particleswas increased. When the composition of SBR bi-modal particles varies about4/6~6/4, the transparency and the impact strength varies unobviously.In this paper, we developed a new method that toughen T-ABS andmaintain its transparency by introducing SiO2 nano-particles into T-ABS resins.The size and content of SiO2 do not influenced its dispersion state in continuousphase;SiO2 particles in a size about 70nm do not influenced the transparency ofT-ABS resins. The transparency of T-ABS descended with increasing size ofSiO2 nano-particles. The regular of the transparency varies of T-ABS usingSiO2/SBR as dispersion phase is similar to using SBR bi-modal particles asdispersion phase. This result indicates that the optical dispersion on the surfaceof particles is the main factor decreasing the transparency.The effect that SiO2 nano-particles toughen T-ABS is the most obviouswhen ABS resins brittle– ductile transition occurs and the mechanical propertiesof the ABS resin were improved with introducing SiO2 nano-particles intodispersion phase. When the content of SiO2 particles is 6% and the content ofSBR is 16%, the impact strength is 148J/m.This method is suitable to prepare T-ABS resins with particular propertiesby introducing brittle particles with particular properties into dispersion phase.