| A novel technique, pan-milling mechanochemistry was developed to modify styrene-butadiene-styrene (SBS) triblock thermoplastic elastomer in solid state at ambient temperature.The unique press and shear stress of the self-designed pan type milling equipment was used to prepare different particle size and particle size distribution of plastic ultra fine powders to fill and modify the SBS, furthermore, the processing temperature was changed to control and optimize the microstructure and interfacial compatibility of plastics in elastomer.The shear stress produced by pan-mill was utilized to exfoliate the lamellar silicate clay mineral (montmorillonite) and the lamellar clay with sub-micron and nano meter particle size was produced, which was separated by the polymer fine powders. The problems of inorganic nano-powders aggregating in high viscosity polymeric matrix and bad interfacial compatibility between inorganic dispersing phase and organic polymeric matrix are therefore solved. This is a new idea to control the inorganic dispersing phase in polymeric matrix by capsulating clay particle with melted plastics and the co-particles deforming to form new gradient modulus and dispersing structure at the processing temperature.The SBS was modified in solid state by MAH, H2O2, CH3COOOH, epoxy resin, phenol and colophony. A new processing method is proposed to introduce a high efficiency and clean physic technique into the chemical modification of elastomer.1. By using TEM, AFM, DSC, XPS, SEM, FTIR, molecular weightAbstractdetermination and mechanical properties testing, the mechanochemical action of the thermopastic elastomer (SBS) was investigated systematically in unique press and shear stress produced by pan type milling equipment. The effects of stress on the pulverizing characteristic, particle shape variation, the change of phase structure, the breaking and crosslinking of molecular chain and the change of mechanical property of SBS were studied.After 18-20 cycles milling, the SBS was pulverized into the powder with the particle size of 50-100 um, the pulverized particle will aggregate to form fibrous structure by further milling. The molecular weight of SBS decreases in milling. The PS domains in SBS are distorted, stretched and moved after milling. The PS domain in some field forms partial continuous phase and the maximum phase size is nearly 100nm. The mechanical properties of SBS change little in milling. The mechanochemical activation of SBS is produced by pan milling, so that the breaking and crosslinking of the SBS molecular chain is accelerated and the SBS is easier oxidized.2. The structure and properties of SBS / different plastic powder blends were studied.The reinforcing effect of SBS filled PP and PS powder was investigated. A new method is proposed in filling PS powder into SBS to substitute the synthetic technological process to change the content of PS block in SBS triblock co-polymer.The structure and properties of SBS /PP/PA6 blends processed in different temperature were investigated. The aim of controlling the plastic microstructure is realized and thus to enhance the properties of the blend by capsulating PA6 particle with melting PP according to the different melting temperature and viscosity of PP and PA6. When the content of the PP/PA6 plastic co-powder is 4-10%, the tensile strengths of the blends enhance nearly double, reaching to 24 MPa, and the tear strength and modulus also increase obviously. The high elasticity of the elastomer is constant. After 48 hours thermo-oxidative aging, the tensile strength of the blend still is the same as that of the SBS before aging and the tear strength is double in the content of the plastic co-powder 6-8%. When the content of plastic co-powder is10-15%, the tensile strength of the blends reaches to 23 MPa after aging. When the content of the co-powder is 4%, the temperatures of 10% weight loss and the maximum weight loss of the blends in TG analysis increase 16.7 癈 and increases 25癈,respectively.Th...
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