In this study,to better understand the reaction mechanism between inorganic salts and nitrocellulose,CaCO_(3) and Li_(2)CO_(3) were evaluated with respect to their effects on the thermal degradation of NC in nitrogen ...In this study,to better understand the reaction mechanism between inorganic salts and nitrocellulose,CaCO_(3) and Li_(2)CO_(3) were evaluated with respect to their effects on the thermal degradation of NC in nitrogen atmosphere using TG/DSC at three different heating rates(2,5,10 K/min).The numerical relationship between activation energy(E)and conversion rate was obtained by FWO and KAS method,and it was discovered that CaCO_(3) could improve the thermal stability of NC.Activation energy values were calculated by Kissinger method,and it was found that NC that contain Li2CO3had the highest activation energy while NC containing CaCO3had the lowest E value.By combining the thermal analysis data with Malek method,the most probable mechanism model of thermal degradation is obtained as Sesták-Berggren model,which expression is f(α)=α^(m)(1-α)^(n).As a result of this study,there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.展开更多
基于4,5-环氧四氢邻苯二甲酸二缩水甘油酯(TDE-85)或N,N,N',N'-四缩水甘油基-4,4'-二氨基二苯基甲烷(AG-80)与2-氨基苯并噻唑(ABZ)的固化反应,以分阶段升温保温方式制备含刚性苯并噻唑链段的TDE-85/ABZ和AG-80/ABZ耐热环氧...基于4,5-环氧四氢邻苯二甲酸二缩水甘油酯(TDE-85)或N,N,N',N'-四缩水甘油基-4,4'-二氨基二苯基甲烷(AG-80)与2-氨基苯并噻唑(ABZ)的固化反应,以分阶段升温保温方式制备含刚性苯并噻唑链段的TDE-85/ABZ和AG-80/ABZ耐热环氧树脂材料.DMTA分析显示,TDE-85/ABZ和AG-80/ABZ固化物玻璃化转变温度分别为473 K和495 K.而TGA分析表明,其最大热降解速率对应温度分别为618 K和643 K,在873 K下仍有11%和13%的残余质量.以非等温DSC法研究TDE-85/ABZ和AG-80/ABZ固化反应动力学得出表观活化能分别为67.72 k J·mol-1和63.57 k J·mol-1,证明TDE-85/ABZ和AG-80/ABZ固化反应是以自催化反应机理进行的,动力学数学模型与DSC实验数据相吻合.这可为TDE-85/ABZ和AG-80/ABZ材料在成型加工工艺参数的优化和选择提供技术支撑.展开更多
基金the National Natural Science Foundation of China(NSFC,Grants No.52176114 and 52111530091)Jiangsu Funding Program for Excellent Postdoctoral Talent。
文摘In this study,to better understand the reaction mechanism between inorganic salts and nitrocellulose,CaCO_(3) and Li_(2)CO_(3) were evaluated with respect to their effects on the thermal degradation of NC in nitrogen atmosphere using TG/DSC at three different heating rates(2,5,10 K/min).The numerical relationship between activation energy(E)and conversion rate was obtained by FWO and KAS method,and it was discovered that CaCO_(3) could improve the thermal stability of NC.Activation energy values were calculated by Kissinger method,and it was found that NC that contain Li2CO3had the highest activation energy while NC containing CaCO3had the lowest E value.By combining the thermal analysis data with Malek method,the most probable mechanism model of thermal degradation is obtained as Sesták-Berggren model,which expression is f(α)=α^(m)(1-α)^(n).As a result of this study,there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.
文摘基于4,5-环氧四氢邻苯二甲酸二缩水甘油酯(TDE-85)或N,N,N',N'-四缩水甘油基-4,4'-二氨基二苯基甲烷(AG-80)与2-氨基苯并噻唑(ABZ)的固化反应,以分阶段升温保温方式制备含刚性苯并噻唑链段的TDE-85/ABZ和AG-80/ABZ耐热环氧树脂材料.DMTA分析显示,TDE-85/ABZ和AG-80/ABZ固化物玻璃化转变温度分别为473 K和495 K.而TGA分析表明,其最大热降解速率对应温度分别为618 K和643 K,在873 K下仍有11%和13%的残余质量.以非等温DSC法研究TDE-85/ABZ和AG-80/ABZ固化反应动力学得出表观活化能分别为67.72 k J·mol-1和63.57 k J·mol-1,证明TDE-85/ABZ和AG-80/ABZ固化反应是以自催化反应机理进行的,动力学数学模型与DSC实验数据相吻合.这可为TDE-85/ABZ和AG-80/ABZ材料在成型加工工艺参数的优化和选择提供技术支撑.
