PMMA/MWCNT复合材料的热降解动力学
|
摘要
采用溶液共混法制备了聚甲基丙烯酸甲酯/多壁碳纳米管(PMMA/MWCNT)复合材料,利用热重法研究了不同气氛下复合材料的热降解,并采用Flynn-Wall-Ozawa、Kissinger和Friedman等3种方法计算其动力学参数。结果表明,MWCNT的添加量为3%时,在氮气和氧气中复合材料的初始降解温度较纯PMMA分别提高了54.62℃和70.4℃,最大热失重速率温度也有一定程度的提高,说明MWCNT能显著提高PMMA的低温热稳定性,尤其是在有氧环境中,而对高温热稳定改善不明显;采用Kissinger法、Flynn-Wall-Ozawa法和Friedman法计算得到的活化能(Ea)变化趋势一致,当MWCNT的添加量为3%时,Ea较纯PMMA提高最多,在氮气中分别为45.99、95.10、72.46kJ/mol,在氧气中分别增加53.42、120.63、110.41kJ/mol;由Friedman法求解出复合材料的反应级数(n)在氮气中约为1.5,在氧气中约为0.9。
The composites based on poly(methyl methacrylate)(PMMA)and multi-walled carbon nanotubes(MWCNT)were prepared by a solution-blending method,and their thermal degradation processes under different atmosphere were investigated by a thermogravimetric method.The kinetic parameters of thermal degradation were obtained by the Flynn-Wall-Ozawa's,Kissinger's and Friedman's methods.The results indicated that the initial degradation temperature of composite containing 3 wt % increased by 54.62 ℃ in nitrogen and 70.4 ℃ in oxygen in comparison with pure PMMA,and its maximum heat loss rate was also improved to some extent.It was concluded that the introduction of MWCNT could effectively improve the low-temperature thermal stability of PMMA,especially in an aerobic environment.However,the improvement in high-temperature thermal stability was not so significant.The values of activation energy(Ea)calculated by Kissinger's,flyn-wall-ozawa's and Friedman's methods were in good agreement with each other.The composites achieved a maximum improvement in Ea when 3 wt % of MWCNT was added into PMMA.In addition,the order of reaction(n)deduced by the Friedman's method for the composites was approximately 1.5 in nitrogen and 0.9 in oxygen.
The composites based on poly(methyl methacrylate)(PMMA)and multi-walled carbon nanotubes(MWCNT)were prepared by a solution-blending method,and their thermal degradation processes under different atmosphere were investigated by a thermogravimetric method.The kinetic parameters of thermal degradation were obtained by the Flynn-Wall-Ozawa's,Kissinger's and Friedman's methods.The results indicated that the initial degradation temperature of composite containing 3 wt % increased by 54.62 ℃ in nitrogen and 70.4 ℃ in oxygen in comparison with pure PMMA,and its maximum heat loss rate was also improved to some extent.It was concluded that the introduction of MWCNT could effectively improve the low-temperature thermal stability of PMMA,especially in an aerobic environment.However,the improvement in high-temperature thermal stability was not so significant.The values of activation energy(Ea)calculated by Kissinger's,flyn-wall-ozawa's and Friedman's methods were in good agreement with each other.The composites achieved a maximum improvement in Ea when 3 wt % of MWCNT was added into PMMA.In addition,the order of reaction(n)deduced by the Friedman's method for the composites was approximately 1.5 in nitrogen and 0.9 in oxygen.
引文
[1]杨瑞芹,陈尔凡,张瑞.提高有机玻璃耐热性的研究进展[J]塑料,1999,28(1):14-18.YANG R Q,CHEN E F,ZHANG R.Research Progress on Improving the Heat Resistance of Plexiglass[J].plastics,1999,28(1):14-18.
[2]张子健.PMMA树脂的力学性能及热稳定性研究[D].长春工业大学.2012.
[3]焦迎春,沈同德,梁沁,等.碳纳米管增强聚甲基丙烯酸甲酯复合材料的研究进展[J].中国塑料.2012(10):16-23.JIAO Y C,SHEN T D,LIANG Q,et al.Research Progress on Carbon Nanotube Reinforced Polymethyl Methacrylate Composites[J].Chinese Plastic.2012(10):16-23.
[4]旭日.相容性高分子共混物—多壁碳纳米管复合材料的导电性研究[D].华东师范大学.2014.
[5]王东卫,赵强,张潇娴,等.碳纳米管/高分子阻燃复合材料研究进展[J].化工新型材料.2012,40(7):4-6.WANG D W,ZHAO Q,ZHANG X X,et al.Research Progress on Carbon Nanotubes/Polymer Flame Retardant Composites[J].New chemical materials.2012,40(7):4-6.
[6]曾文茹,李疏芬,周允基.聚甲基丙烯酸甲酯热氧化降解的化学动力学研究[J].化学物理学报.2003,16(1):64-68.ZENG W R,LI S F,ZHOU Y J,et al.Study on Chemical Kinetics of Thermal Oxidation Degradation of Polymethyl Methacrylate[J].Journal of Chemical Physics.2003,16(1):64-68.
[7]GRASSIE N,SCOTT G.Polymer Degradation and Stabilization[D].Cambridge:Cambridge University Press,1985.
[8]PETERSON D T,SERGEY V,CHARLES A.Wight Kinetic Study of Stability Effect of Oxygen on Themaldegradation of Poly(methylmethacrylate)[J].J Phys ChemB,1999,103(38):8 087-8 092.
[9]KISSINGER H E.Reaction Kinetics in Differential Thermal Analysis[J].Analytical Chemistry,1957,29(11):1 702-1 706.
[10]JOSEPH H F,LEO A W.A Quick,Direct Method for the Determination of Activation Ernergy from Thermogravimetric Data[J].Journal of Polymer Science Part C:Polymer Letters,1966,4(5):323-328.
[11]何小芳,孙得翔,曹新鑫,等.聚丙烯/煤泥复合材料热降解动力学研究[J].化工新型材料.2016,41(2):169-174.HE X F,SUN D X,CAO X X,et al.Study on Thermal Degradation Kinetics of Polypropylene/Coal mud Composites[J].New chemical materials.2016,41(2):169-174.
[12]CIARDELLI F,COIAI S,PASSAGLIA E.Nanocomposites Based on Polyolefins and Functional Thermoplastic Materials[J].Polymer International,2008,57(6):805-836.
[13]HUXTABLE S T,CAHILL D G,SHENOGIN S,et al.Interfacial Heat Flow in Carbon Nanotube Suspensions[J].Nature Materials,2003,2(11):731-734.
[2]张子健.PMMA树脂的力学性能及热稳定性研究[D].长春工业大学.2012.
[3]焦迎春,沈同德,梁沁,等.碳纳米管增强聚甲基丙烯酸甲酯复合材料的研究进展[J].中国塑料.2012(10):16-23.JIAO Y C,SHEN T D,LIANG Q,et al.Research Progress on Carbon Nanotube Reinforced Polymethyl Methacrylate Composites[J].Chinese Plastic.2012(10):16-23.
[4]旭日.相容性高分子共混物—多壁碳纳米管复合材料的导电性研究[D].华东师范大学.2014.
[5]王东卫,赵强,张潇娴,等.碳纳米管/高分子阻燃复合材料研究进展[J].化工新型材料.2012,40(7):4-6.WANG D W,ZHAO Q,ZHANG X X,et al.Research Progress on Carbon Nanotubes/Polymer Flame Retardant Composites[J].New chemical materials.2012,40(7):4-6.
[6]曾文茹,李疏芬,周允基.聚甲基丙烯酸甲酯热氧化降解的化学动力学研究[J].化学物理学报.2003,16(1):64-68.ZENG W R,LI S F,ZHOU Y J,et al.Study on Chemical Kinetics of Thermal Oxidation Degradation of Polymethyl Methacrylate[J].Journal of Chemical Physics.2003,16(1):64-68.
[7]GRASSIE N,SCOTT G.Polymer Degradation and Stabilization[D].Cambridge:Cambridge University Press,1985.
[8]PETERSON D T,SERGEY V,CHARLES A.Wight Kinetic Study of Stability Effect of Oxygen on Themaldegradation of Poly(methylmethacrylate)[J].J Phys ChemB,1999,103(38):8 087-8 092.
[9]KISSINGER H E.Reaction Kinetics in Differential Thermal Analysis[J].Analytical Chemistry,1957,29(11):1 702-1 706.
[10]JOSEPH H F,LEO A W.A Quick,Direct Method for the Determination of Activation Ernergy from Thermogravimetric Data[J].Journal of Polymer Science Part C:Polymer Letters,1966,4(5):323-328.
[11]何小芳,孙得翔,曹新鑫,等.聚丙烯/煤泥复合材料热降解动力学研究[J].化工新型材料.2016,41(2):169-174.HE X F,SUN D X,CAO X X,et al.Study on Thermal Degradation Kinetics of Polypropylene/Coal mud Composites[J].New chemical materials.2016,41(2):169-174.
[12]CIARDELLI F,COIAI S,PASSAGLIA E.Nanocomposites Based on Polyolefins and Functional Thermoplastic Materials[J].Polymer International,2008,57(6):805-836.
[13]HUXTABLE S T,CAHILL D G,SHENOGIN S,et al.Interfacial Heat Flow in Carbon Nanotube Suspensions[J].Nature Materials,2003,2(11):731-734.