粮食与油脂
糧食與油脂
양식여유지
CEREALS & OILS
2014年
11期
52-56
,共5页
β-谷甾醇%热解%热动力学%TG-DTG/DTA
β-穀甾醇%熱解%熱動力學%TG-DTG/DTA
β-곡치순%열해%열동역학%TG-DTG/DTA
β-sitosterol%pyrolysis%kinetics%TG-DTG/DTA
β–谷甾醇是食品和医学领域广泛使用,且是植物界最普遍存在的甾醇。用TG–DTG/DTA方法研究了两种含量分别为40%和80%的β–谷甾醇热解过程及热动力学。TG和DTG分析结果表明,该物质的失重过程分两步完成。第一步为结晶水脱出,第二步为甾醇裂解和挥发性物质蒸发。热解过程中,加热速率对两种植物甾醇热解有显著作用。使用Popescu分别计算出40%和80%β–谷甾醇的热解活化能分别为111和132 kJ/mol。对常用41种热解动力学机理函数,确定了两种植物甾醇热解过程均为三维扩散的反Jander方程(g(α)=[(1+α)1/3–1]2。
β–穀甾醇是食品和醫學領域廣汎使用,且是植物界最普遍存在的甾醇。用TG–DTG/DTA方法研究瞭兩種含量分彆為40%和80%的β–穀甾醇熱解過程及熱動力學。TG和DTG分析結果錶明,該物質的失重過程分兩步完成。第一步為結晶水脫齣,第二步為甾醇裂解和揮髮性物質蒸髮。熱解過程中,加熱速率對兩種植物甾醇熱解有顯著作用。使用Popescu分彆計算齣40%和80%β–穀甾醇的熱解活化能分彆為111和132 kJ/mol。對常用41種熱解動力學機理函數,確定瞭兩種植物甾醇熱解過程均為三維擴散的反Jander方程(g(α)=[(1+α)1/3–1]2。
β–곡치순시식품화의학영역엄범사용,차시식물계최보편존재적치순。용TG–DTG/DTA방법연구료량충함량분별위40%화80%적β–곡치순열해과정급열동역학。TG화DTG분석결과표명,해물질적실중과정분량보완성。제일보위결정수탈출,제이보위치순렬해화휘발성물질증발。열해과정중,가열속솔대량충식물치순열해유현저작용。사용Popescu분별계산출40%화80%β–곡치순적열해활화능분별위111화132 kJ/mol。대상용41충열해동역학궤리함수,학정료량충식물치순열해과정균위삼유확산적반Jander방정(g(α)=[(1+α)1/3–1]2。
β–sitosterol is widely used in food and medicine,and is ubiquitous in plantage. Thermal decomposition and kinetics of 40%β–sitosterol and 80%β–sitosterol were studied by TG–DTG/DTA. The TG–DTG curve showed the process of mass loss of the substance proceeded in two steps. The first stage could be attributed to the expulsion of water of crystallization. The second stage was corresponding to the devolatilization and decomposition of the molecular structure. Heating rate had a significant effect on the pyrolysis of the two phytosterols. The activation energy E of the second stage of degradation process obtained by Popescu method were 111(for 40%β–sitosterol)and 132 kJ/mol (for 80%β–sitosterol). According to Popescu mechanism functions,the possible kinetic model was estimated to be Reverse Jander Equation(g(α)=[(1+α)1/3–1]2.