Research Of Properties Of DAOP Modified Polyphenylene Oxide And Composite Materials

Polyphenylene oxide is one of five engineering thermoplastics.Polyphenyleneoxide (PPO) possess desirable properties such as excellent electrical insulatingproperties, good mechanical properties and heat resistance.But pure PPO because ofheavy melt viscosity and processing temperature limits its practical application.Thisarticle use the thermosetting resin（DAOP）as the activity of PPO plasticizingmodifier, improve the processing properties of polyphenylene oxide.First DAOPcuring reaction in the PPO and phase changes have great influences on theblends.Rheology,DMA, SEM analysis and observations of the blends cured with DCPindicated phase transition.Second,the processing temperature with low-boiling DAOPwas still higher than boiling point of DAOP.Therefore,control the curing rate ofDAOP becomes critical. DMDPB gear with matrix for blends with>90wt%PPO,single initiator DCP is suitable for blends with <70wt%PPO.Single initiatordoes not meet the Arbitrary proportion of DAOP/PPO.However,complex initiationsystem can balance the processing characteristics and overall property ofPPO,preparing the PPO/DAOP/OMMT composites.Steady shear rheology during cure of PPO:DAOP/DCP at140℃,160℃at shearfrequency of1Hz. The gelation time of blends with10wt%,20wt%,30wt%wasabout500s,600s,750s,respectively.Phase analysis shows, intersection region showedthat they did not vary significantly with PPO content up to40wt%,but suddenlyincreased above50wt%PPO.DMA analysis showed that the system appeared aTg,phase separation did not occur. SEM observations of the blends indicated aco-continuous morphology for blends with40wt%PPO,and a phase inverted blendswith more than50wt%PPO.Torque rheological showed the speed of30r/min,contentof1.5wt%DCP,the processing time of7min fit70PPO/30DAOP preceding cure. ByHigh-speed action, PPO/DAOP hybrid systems exhibit shear thickening mechanis-m,because the probability of polyphenylene ether free space among small moleculesor monomers of free radicals contact with each other frequently.polymerizationdegree of crosslinking increases significantly.synergies of curing and shear rate needto keep a balance. The mechanical properties showed DAOP was added to improve processabilit-y.The hardness of the material remains constant.The mechanical modulus of themixed system decline, but the strength increased. So DAOP can improve mobility ofPPO, have a certain influence on the mechanical properties of the material. TGanalysis showed that complex initiation system after curing, thermal properties ofeach component can be improved and enhanced, and heat resistance compared withpure polyphenylene ether or less, so the process on the basis of improving the heatperformance has been very good to keep.By melt blending,the treated montmorillonite was added into PPO/DAOPcomposites.75PPO/25DAOP initiator system optimized by torque rheometer.DAOPcan facilitate intercalation effect of OMMT.With the increase of the content and theextension processing DAOP,DAOP can further increase the lamella spacing and havegood dispersion.