通过再参数化PC-SAFT状态方程,建立了丙烯-氢气-聚丙烯体系各组分物性的计算方法。以文献数据为基准,利用Polym er P lus软件平台,分别得到了丙烯、氢气、聚丙烯纯组分的PC-SAFT方程的模型参数,包括链段数m、链段直径σ、能量参数ε/kB...通过再参数化PC-SAFT状态方程,建立了丙烯-氢气-聚丙烯体系各组分物性的计算方法。以文献数据为基准,利用Polym er P lus软件平台,分别得到了丙烯、氢气、聚丙烯纯组分的PC-SAFT方程的模型参数,包括链段数m、链段直径σ、能量参数ε/kB以及丙烯-氢气两组分相平衡的二元交互参数kij。结果表明,采用再参数化的PC-SAFT状态方程计算丙烯、氢气热力学性质的精度优于经典的Peng-Rob inson方程。展开更多
The residence time distribution (RTD) evolution along a co-rotating twin-screw extruder with a split barrel was experimentally investigated by using the pre-mixed particles of polystyrene (PS) with anthracene as the t...The residence time distribution (RTD) evolution along a co-rotating twin-screw extruder with a split barrel was experimentally investigated by using the pre-mixed particles of polystyrene (PS) with anthracene as the tracer.The samples on the screw were taken out from the specially designed extruder, which could be dead-stopped at a given time and its barrel opened within several seconds.A three-parameter function was used to fit the experimentally measured RTD.The calculated results fit the experimental data very well.The reverse screw elements and kneading block had much longer residence time and resulted in effective mixing.Based on the average residence time of different screw zones and volume flow rate of molten PS, the fill degree in different screw zones was estimated.The fill degree results proved that the similar structure of screw elements might have different degrees of fill due to the effect of neighboring elements, and too close alignment of kneading zones might lead to ‘besiegement’ of materials in the zone between them.展开更多
Poly(styrene-acrylonitrile) emulsion particles with positive charges on the surface were synthesized by emulsion polymerization using cationic surfactant octotyltrimethyl ammonium chloride (OTAC) as emulsifier.The sus...Poly(styrene-acrylonitrile) emulsion particles with positive charges on the surface were synthesized by emulsion polymerization using cationic surfactant octotyltrimethyl ammonium chloride (OTAC) as emulsifier.The suspension of montmorillonite was slowly dropped into the emulsion.Through the interaction between the negative charges on the montmorillonite layers and the cations on the surface of poly(styrene-acrylonitrile) particles, the montmorillonite layers and emulsion particles could assemble and absorb on each other by themselves.The change of δ voltage and particle size of the emulsion during the process of dropping was characterized, which demonstrated that the emulsion particles and montmorillonite layers absorbed on each other by the electrovalent bond and an intersectional structure was formed in the complex emulsion.Poly(styrene-acrylonitrile)/ montmorillonite nanocomposite was obtained after coagulation.The structure of nanocomposite was characterized with XRD and TEM.The results indicated that montmorillonite was exfoliated into layers with a thickness of several nanometers and uniformly dispersed in the polymer matrix.展开更多
文摘通过再参数化PC-SAFT状态方程,建立了丙烯-氢气-聚丙烯体系各组分物性的计算方法。以文献数据为基准,利用Polym er P lus软件平台,分别得到了丙烯、氢气、聚丙烯纯组分的PC-SAFT方程的模型参数,包括链段数m、链段直径σ、能量参数ε/kB以及丙烯-氢气两组分相平衡的二元交互参数kij。结果表明,采用再参数化的PC-SAFT状态方程计算丙烯、氢气热力学性质的精度优于经典的Peng-Rob inson方程。
文摘The residence time distribution (RTD) evolution along a co-rotating twin-screw extruder with a split barrel was experimentally investigated by using the pre-mixed particles of polystyrene (PS) with anthracene as the tracer.The samples on the screw were taken out from the specially designed extruder, which could be dead-stopped at a given time and its barrel opened within several seconds.A three-parameter function was used to fit the experimentally measured RTD.The calculated results fit the experimental data very well.The reverse screw elements and kneading block had much longer residence time and resulted in effective mixing.Based on the average residence time of different screw zones and volume flow rate of molten PS, the fill degree in different screw zones was estimated.The fill degree results proved that the similar structure of screw elements might have different degrees of fill due to the effect of neighboring elements, and too close alignment of kneading zones might lead to ‘besiegement’ of materials in the zone between them.
文摘Poly(styrene-acrylonitrile) emulsion particles with positive charges on the surface were synthesized by emulsion polymerization using cationic surfactant octotyltrimethyl ammonium chloride (OTAC) as emulsifier.The suspension of montmorillonite was slowly dropped into the emulsion.Through the interaction between the negative charges on the montmorillonite layers and the cations on the surface of poly(styrene-acrylonitrile) particles, the montmorillonite layers and emulsion particles could assemble and absorb on each other by themselves.The change of δ voltage and particle size of the emulsion during the process of dropping was characterized, which demonstrated that the emulsion particles and montmorillonite layers absorbed on each other by the electrovalent bond and an intersectional structure was formed in the complex emulsion.Poly(styrene-acrylonitrile)/ montmorillonite nanocomposite was obtained after coagulation.The structure of nanocomposite was characterized with XRD and TEM.The results indicated that montmorillonite was exfoliated into layers with a thickness of several nanometers and uniformly dispersed in the polymer matrix.
