Thermal degradation processes and kinetics of composites based on ultrafine coal powder and high density polyethylene （HDPE）, linear low density polyethylene （LLDPE） or low density polyethylene （LDPE） at differe...Thermal degradation processes and kinetics of composites based on ultrafine coal powder and high density polyethylene （HDPE）, linear low density polyethylene （LLDPE） or low density polyethylene （LDPE） at different compositions were studied by means of thermogravimetric analysis （TG） and differential scanning calorimetry （DSC） in present work, to improve understandings in stabilization or degradation control of the composite. The results indicated that the coal facilitates melting of the polyethylene slightly before onset temperature, some chemical interactions were also observed in the composite. Coal participates in chain initiation, transfer and termination of the polymer, influences on thermal stability of composites lie in hydrogen acceptor effect of the coal. The thermal decomposition of the coals and the polymers can be modeled via the first order parallel reactions models in low temperatLire range. In higher temperature case, combination of aromatic macromolecular radical from coal with polymeric macromolecular radical gives rise to the greater activation energies of decomposition, thermal decomposition of the composites comply to step-by-step consecutive reactions models. Coal can be used as important degradation controlling additive to prepare functional materials.展开更多
基金National Natural Science Foundation of China(20276056)the Science and Technology Key Problem Plan of Shannxi Province(No.2000K10-G9)
文摘Thermal degradation processes and kinetics of composites based on ultrafine coal powder and high density polyethylene （HDPE）, linear low density polyethylene （LLDPE） or low density polyethylene （LDPE） at different compositions were studied by means of thermogravimetric analysis （TG） and differential scanning calorimetry （DSC） in present work, to improve understandings in stabilization or degradation control of the composite. The results indicated that the coal facilitates melting of the polyethylene slightly before onset temperature, some chemical interactions were also observed in the composite. Coal participates in chain initiation, transfer and termination of the polymer, influences on thermal stability of composites lie in hydrogen acceptor effect of the coal. The thermal decomposition of the coals and the polymers can be modeled via the first order parallel reactions models in low temperatLire range. In higher temperature case, combination of aromatic macromolecular radical from coal with polymeric macromolecular radical gives rise to the greater activation energies of decomposition, thermal decomposition of the composites comply to step-by-step consecutive reactions models. Coal can be used as important degradation controlling additive to prepare functional materials.
