4-乙基苯酚低聚物抗氧剂对聚丙烯热和流变性能的影响
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摘要
分别采用热重分析仪、差示扫描量热仪、X-射线粉末衍射仪和旋转流变仪研究了添加了0. 5%的4-乙基苯酚低聚物抗氧剂的聚丙烯复合材料(PP-A)的热性能和流变性能变化。热分析结果表明,加入抗氧剂后的PP-A在空气气氛下的热氧稳定性提高,其分解温度提高了9℃。结晶温度向低温区移动了5℃,结晶峰半峰宽变宽,结晶速率变慢。X射线粉末衍射仪测试表明PP-A的晶型未发生变化。流变测试结果表明PP-A的复数黏度η*、储能模量G'、损耗模量G″均较纯PP升高,随着角频率的增大,剪切稀化现象明显,呈假塑性流体变化。4-乙基苯酚低聚物抗氧剂抑制了PP的氧化降解。纯PP和PP-A的加权松弛谱表明抗氧剂的加入避免了PP轻微的氧化交联现象。
The changes in thermal and rheological characterization of polypropylene composite( PP-A) with addition of0. 5% 4-ethylphenol oligomer antioxidant were investigated by thermogravimetric analysis( TGA), differential scanning calorimetry( DSC),X-ray powder diffractometer( XRD) and rotational rheometer. TGA shows that 4-ethylphenol oligomer antioxidant could enhance the thermal stability of polypropylene in air atmosphere. The temperature of decomposition is 9 ℃higher than the pure polypropylene( PP). DSC shows that the crystallization peak moves 5 ℃ toward low temperature region,the half-peak width of crystal peak becomes wider,the crystallization rate becomes slower. XRD indicates that no change in crystal type of PP-A is observed. Rheological behavior of PP-A shows that complex viscosity,storage modulus( G') and loss modulus( G″) could increase. Its shear thinning tendency increases with increasing frequency,which exhibits pseudoplastic fluid. The antioxidant inhibits the oxidative degradation of PP. The weighted relaxation spectra indicates that the addition of antioxidant could prevent PP from slightly crosslinking.
The changes in thermal and rheological characterization of polypropylene composite( PP-A) with addition of0. 5% 4-ethylphenol oligomer antioxidant were investigated by thermogravimetric analysis( TGA), differential scanning calorimetry( DSC),X-ray powder diffractometer( XRD) and rotational rheometer. TGA shows that 4-ethylphenol oligomer antioxidant could enhance the thermal stability of polypropylene in air atmosphere. The temperature of decomposition is 9 ℃higher than the pure polypropylene( PP). DSC shows that the crystallization peak moves 5 ℃ toward low temperature region,the half-peak width of crystal peak becomes wider,the crystallization rate becomes slower. XRD indicates that no change in crystal type of PP-A is observed. Rheological behavior of PP-A shows that complex viscosity,storage modulus( G') and loss modulus( G″) could increase. Its shear thinning tendency increases with increasing frequency,which exhibits pseudoplastic fluid. The antioxidant inhibits the oxidative degradation of PP. The weighted relaxation spectra indicates that the addition of antioxidant could prevent PP from slightly crosslinking.
引文
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[7]辜婷,朱大勇,郑强,等.多巴胺改性滑石粉对聚乳酸/聚丁二酸丁二醇酯共混体系结晶行为及流变性能的影响[J].高分子材料科学与工程,2017,33(9):65-71.
[8]热依扎·别坎,马俊红,倪玲贵,等.不同抗氧剂体系对聚丙烯热氧光老化的稳定作用[J].中国塑料,2017,31(5):78-83.
[9]JOHN D F.Viscoelastic properties of polymers[M].3rd E-dition.New York:John Wiley&Sons,1980:84.
[2]CATERINA V,STEFANO M,GIULIO A,et al.Ethylene/hindered phenol substituted norbornene copolymers:Synthesis and NMR structural determination[J].J Polym Sci,Pat A:Polym Chem,2012,50(22):4647-4655.
[3]GAO Y H,JIANG F,ZHANG L,et al.Enzymatic synthesis of polyguaiacol and its thermal antioxidant behavior in polypropylene[J].Polym Bull,2016,73(5):1343-1359.
[4]DURMUS A,YALCINYUVA T.Effects of additives on nonisothermal crystallization kinetics and morphology of isotactic polypropylene[J].J Polym Res,2009,16(5):489-498.
[5]刘先龙,李娟,伍玉娇,等.非等温结晶动力学研究不同抗氧剂对PP/NA-11性能的影响[J].塑料工业,2015,43(2):81-85.
[6]柴春晓,江帆,郑轲,等.4-乙基苯酚低聚物的酶催化合成及抗氧化性能研究[J].化学研究,2017,28(4):487-492.
[7]辜婷,朱大勇,郑强,等.多巴胺改性滑石粉对聚乳酸/聚丁二酸丁二醇酯共混体系结晶行为及流变性能的影响[J].高分子材料科学与工程,2017,33(9):65-71.
[8]热依扎·别坎,马俊红,倪玲贵,等.不同抗氧剂体系对聚丙烯热氧光老化的稳定作用[J].中国塑料,2017,31(5):78-83.
[9]JOHN D F.Viscoelastic properties of polymers[M].3rd E-dition.New York:John Wiley&Sons,1980:84.