注塑级聚乳酸热分解动力学分析  

Thermal Decomposition Kinetics Analysis of Injection Grade Polylactic Acid

作　　者：罗越峰 温桦浩 廖正福[1] LUO Yuefeng;WEN Huahao;LIAO Zhengfu(School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学材料与能源学院,广州510006

出　　处：《包装工程》2024年第7期45-52,共8页Packaging Engineering

摘　　要：目的研究注塑级聚乳酸材料的热分解动力学,准确理解注塑级聚乳酸的耐热稳定性,为开发耐高温阻燃注塑级聚乳酸(PLA)材料提供理论依据。方法通过非等温热重分析法,采用5、10、15、20、25℃/min的升温速率,研究注塑级PLA在氮气气氛中的热分解行为,利用1种微分法和3种积分法进行详细的动力学计算。比较相关系数及标准偏差,选取KAS等温积分法,以相对偏差Ai=|1–αc/αe|为目标函数,利用16种热分解动力学机理模拟计算注塑级PLA热分解最合适的反应机理。结果得到了注塑级PLA热分解所需的活化能和指前因子,其中Kissinger、Madhusudanan-Krishnan-Ninan(MKN)、Kissinger-Akahira-Sunose(KAS)和Flynn-Wall-Ozawa(FWO)法计算所得注塑级PLA活化能分别为177.01、174.43、173.01和173.28 kJ/mol。指前因子分别为25.84、26.69~33.75、25.83~32.89和26.38~32.94。结论确定了随机成核和随后生长反应机理(A1/4),ln(β/T2)=ln[4.75×10^(9)/–ln(1–α)]–2.08×10^(4)/T是描述注塑级PLA热分解最合适的反应机理。The work aims to study the thermal decomposition kinetics of injection grade polylactic acid(PLA)and accurately understand the heat stability of injection grade polylactic acid(PLA),so as to provide theoretical basis for developing high temperature and flame retardant injection grade polylactic acid(PLA)materials.By non isothermal weight analysis,the heating rate of 5,10,15,20 and 25℃/min was adopted to analyze the thermal decomposition behavior of injection grade PLA in nitrogen atmosphere.One differential method and three integral methods were used to carry out the detailed kinetics calculation.The correlation coefficient and standard deviation were compared.KAS isothermal integration method was selected,and with relative deviation Ai=|1–αc/αe|as the objective function,16 kinds of thermal decomposition kinetics mechanisms were used to simulate and calculate the most appropriate reaction mechanism for the thermal decomposition of injection grade PLA.The activation energy and pre-exponential factors required for thermal decomposition of injection grade PLA were obtained.The activation energies of injection grade PLA calculated by Kissinger,Madhusudanan-Krishnan-Ninan(MKN),Kissinger-Akahira-Sunose(KAS)and Flynn-Wall-Ozawa(FWO)were 177.01,174.43,173.01 and 173.28 kJ/mol,respectively.The pre-exponential factors were 25.84,26.69-33.75,25.83-32.89 and 26.38-32.94,respectively.The random nucleation and subsequent growth reaction mechanism(A1/4)are determined and ln(β/T2)=ln[4.75×10^(9)/–ln(1–α)]–2.08×10^(4)/T is the most appropriate description of injection grade PLA thermal decomposition reaction mechanism.

关 键 词：注塑级聚乳酸 热分解动力学 非等温分析 反应机理 

分 类 号：TB324[一般工业技术—材料科学与工程]