Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of...Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of micro-nanospheres with cyclic cross-linked poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol)(PZS). A new organic-inorganic poly(phosphonitrile)-modified aluminum hypophosphite microspheres(PZS-AHP) were synthesized by encapsulation and applied to flame retardant thermoplastic polyurethane(TPU). The microstructure and chemical composition of the PZS-AHP microsphere were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray spectroscopy. The thermal stability of PZS-AHP microsphere was explored with thermogravimetric analysis. Thermogravimetric data indicate that the PZS-AHP microspheres have excellent thermal stability. The thermal and flame-retarding properties of the TPU composites were evaluated by thermogravimetric(TG), limited oxygen index tests(LOI), and cone calorimeter test(CCT). The TPU composite achieved vertical burning(UL-94) V-0 grade and LOI value reached 29.2% when 10 wt% PZS-AHP was incorporated. Compared with those of pure TPU, the peak heat release rate(pHRR) and total heat release(THR) of TPU/10%PZS-AHP decreased by 82.2% and 42.5%, respectively. The results of CCT indicated that PZS-AHP microsphere could improve the flame retardancy of TPU composites.展开更多
为了系统性地探究广西主要蔗区的赤红壤及开沟接触部件相互作用的离散元仿真参数,采用EDEM中的Hertz-Mindlin with JKR模型,基于斜板碰撞试验方法,将显著因素采用响应曲面优化方法进行回归分析,建立回归方程,得到表面能JKR在土壤含水率...为了系统性地探究广西主要蔗区的赤红壤及开沟接触部件相互作用的离散元仿真参数,采用EDEM中的Hertz-Mindlin with JKR模型,基于斜板碰撞试验方法,将显著因素采用响应曲面优化方法进行回归分析,建立回归方程,得到表面能JKR在土壤含水率为5%、10%、15%情况下分别为3.03、5.756、7;通过Design-expert软件中的优化设计模块结合堆积角物理试验,分别以水平距离32.5、33.94、33.85cm为目标,固定静摩擦因数,并利用回归方程预测出多组优化解,得到水平距离分别为32.4、33.94、33.66cm,与实际误差小于5%。固定静摩擦因数后,将显著因素代入回归方程得出堆积角分别为31.85°、41.44°、47.34°,与实际的堆积角30.67°、40°、46.49°误差分别为4%、4%、2%,均小于5%,土壤与土壤接触参数与实际基本一致。开展田间试验测定扭矩,通过对比仿真和实际的旋耕功耗误差,验证EDEM仿真模型中土壤标定试验参数的准确性。在EDEM仿真试验中,选取一把旋耕弯刀进行分析,其平均合力约为133N,而田间试验条件下为144.3N,两者误差7.8%,说明土壤模型与实际基本符合。研究结果及方法准确可靠,可为基于离散元法研制适用于广西赤红壤地质条件的甘蔗相关机械提供理论依据。展开更多
基金Supported by the Opening Project of Hubei Three Gorges Laboratory (No.SK213008)the Innovation Fund of Key Laboratory of Green Chemical Process of Ministry of Education (No.GCXP202109)。
文摘Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of micro-nanospheres with cyclic cross-linked poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol)(PZS). A new organic-inorganic poly(phosphonitrile)-modified aluminum hypophosphite microspheres(PZS-AHP) were synthesized by encapsulation and applied to flame retardant thermoplastic polyurethane(TPU). The microstructure and chemical composition of the PZS-AHP microsphere were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray spectroscopy. The thermal stability of PZS-AHP microsphere was explored with thermogravimetric analysis. Thermogravimetric data indicate that the PZS-AHP microspheres have excellent thermal stability. The thermal and flame-retarding properties of the TPU composites were evaluated by thermogravimetric(TG), limited oxygen index tests(LOI), and cone calorimeter test(CCT). The TPU composite achieved vertical burning(UL-94) V-0 grade and LOI value reached 29.2% when 10 wt% PZS-AHP was incorporated. Compared with those of pure TPU, the peak heat release rate(pHRR) and total heat release(THR) of TPU/10%PZS-AHP decreased by 82.2% and 42.5%, respectively. The results of CCT indicated that PZS-AHP microsphere could improve the flame retardancy of TPU composites.
文摘为了系统性地探究广西主要蔗区的赤红壤及开沟接触部件相互作用的离散元仿真参数,采用EDEM中的Hertz-Mindlin with JKR模型,基于斜板碰撞试验方法,将显著因素采用响应曲面优化方法进行回归分析,建立回归方程,得到表面能JKR在土壤含水率为5%、10%、15%情况下分别为3.03、5.756、7;通过Design-expert软件中的优化设计模块结合堆积角物理试验,分别以水平距离32.5、33.94、33.85cm为目标,固定静摩擦因数,并利用回归方程预测出多组优化解,得到水平距离分别为32.4、33.94、33.66cm,与实际误差小于5%。固定静摩擦因数后,将显著因素代入回归方程得出堆积角分别为31.85°、41.44°、47.34°,与实际的堆积角30.67°、40°、46.49°误差分别为4%、4%、2%,均小于5%,土壤与土壤接触参数与实际基本一致。开展田间试验测定扭矩,通过对比仿真和实际的旋耕功耗误差,验证EDEM仿真模型中土壤标定试验参数的准确性。在EDEM仿真试验中,选取一把旋耕弯刀进行分析,其平均合力约为133N,而田间试验条件下为144.3N,两者误差7.8%,说明土壤模型与实际基本符合。研究结果及方法准确可靠,可为基于离散元法研制适用于广西赤红壤地质条件的甘蔗相关机械提供理论依据。
