Interface Design Of Hollow Microsphere-Filled Polymer Composites And Its Influence On Structure And Properties

The interface bonding is undoubtedly one of the most important factors that haveinfluence on the properties of rigid inorganic filler filled polymer composites. Theinterface can not only makes a linkage between the filler and the matrix, but alsotransfers the stress and other message. Therefore, it has been a focus of attention toimprove the interface compatibility in the field of rigid inorganic particle filledpolymer composites. In this work, the interfaces of hollow glass microspheres (HGM)filled polypropylene (PP) and silicone rubber composites were optimized anddesigned. And, the influence of interface design on the structure and performance ofcomposites was investigated.As a toughener and compatibilizer, maleated poly(ethylene-octene)(POE-g-MAH) was incorporated into PP/HGM binary composites, and the structureand performance of PP composites modified with elastomer coated HGM werestudied. The results of experiment show that, POE-g-MAH improved the interfacialadhesion of PP/HGM composite; in addition, the amination of HGM could also affectthe final microstructure of the ternary composites. Compared with untreated HGM,these HGM after amination treatment acquire a lot of active amine groups, whichcould react with POE-g-MAH during melt compounding to enhance the interfaceadhesion. Thus, an elastomer interface layer around HGM was formed, andsubsequently a core-shell microstructure in the ternary composites was produced. Theresults of thermal analysis showed that, when HGM was coated by the elastomer, itsinduction ofβ-crystal nucleation in PP matrix seemed to become no longer apparent;the nucleation activity was also inhibited by elastomer interface layer during thecrystallization process, and the crystallization degree was declined obviously. The testof mechanical properties showed that the core-shell microstructure existed in theternary composites was beneficial to the mechanical properties. Non-isothermalcrystallization kinetics analysis showed that, the growth rate of PP crystals wasreduced by the elastomer coated "larger particles", the nucleation and growthmechanism was also changed, and the diffusion activation energy of crystallizationincreased significantly.Solution of rare earth element was used to modify the surface of HGM, and thenthe treated and untreated HGM were added into methyl vinyl silicone rubber (VMQ) to prepare a silicone rubber based damping materials. The effect of rare earth elementtreatment on the interface adhesion, tensile strength and dynamic mechanicalproperties of the silicone rubber based damping materials was studied. The results ofscanning electron microscopy and mechanical properties showed that, when HGMwas modified with rare earth element the interface compatibility of damping materialswas improved , which led to improve the tensile strength of damping materials.Dynamic mechanical analyses showed that the addition of HGM into VMQ had asignificant effect on the loss factor (tanδ) of damping materials: when the VMQ wasfilled with untreated HGM, the peak of tanδincreased about 18.2%; and when theVMQ was filled with HGM treated by rare earth element, the peak of tanδincreasedabout 31.5%.