摘要:
对熔融插层法所制备的纳米蒙脱土/聚丙烯（OMMT1/PP）复合材料, 分别在100℃、 110℃、 120℃进行0～12d的热氧老化, 考察其热性能、 热稳定性、 拉伸强度的衰减及其动力学。TG、 DSC、 FTIR分析结果表明： 纳米OMMT1/PP复合材料比PP的热分解温度升高37℃, 结晶度由51%提高到71%, 而且有机化的纳米MMT片层与PP之间存在较强的作用, 因此热氧作用的C O吸收峰明显弱化, 表面轻微开裂。100～120℃老化后OMMT1/PP的强度保持率大大优于纯聚丙烯材料（8~22倍）, OMMT1/PP 110℃老化12d后拉伸强度仍然达54％。建立了以拉伸强度?问腛MMT1/PP热氧老化的一级反应动力学方程, 其热氧老化反应的活化能为52.3kJ/mol, 为PP的1.7倍。分析认为： OMMT1/PP较高的活化能值以及优良的抗热氧老化能力来自其剥离型纳米化MMT片层对PP的力学?ぷ饔谩?物理阻隔效应以及OMMT1与PP之间化学交互作用的综合结果。
Abstract:
Organ montmorillonite (OMMT1)/polypropylene (PP) nanocomposites were prepared by the melt intercalation method. After thermal-oxidative aging for 0 ~ 12d at the temperature of 100℃, 110℃ and 120℃, the thermal property, thermal stability, the attenuation of tensile strength and kinetics were studied. The results of TG, DSC and FTIR show that, compared with PP, the thermal decomposition temperature of OMMT1/PP increases by 37℃, the crystallinity increases from 51% to 71%, and there is stronger interaction between nano-OMMT lamellar and PP.So CO vibration absorption peaks of OMMT1/PP weaken significantly in FTIR spectra and surface cracks slightly during thermal-oxidative aging. After aging at 100~120℃, strength retention of OMMT1/PP is much superior to pure polypropylene material (8~22 times), and its tensile strength was 54% after 12 d aging at 110℃. The first-order kinetics equation of OMMT1/PP thermal-oxidative aging was established with tensile strength as parameter, its activation energy was 52.3kJ/mol (1.7 times of PP). The higher the activation energy values and excellent resistance to thermal-oxidative aging of OMMT1/PP can be contributed to the mechanical protection of exfoliated nano-MMT lamella, physical barrier effect to PP and the chemical interaction between MMT and PP.
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