Preparation of polyethyleneimine-decorated fullerene and its effect on thermal stability of polypropylene
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摘要: 利用聚乙烯亚胺(PEI)分子中活泼的−NH−与富勒烯(C60)结构中C=C键之间的加成反应,制备了PEI修饰C60杂化物(C60−PEI),并采用FTIR、TEM等测试方法对C60−PEI的分子结构和形态进行表征。采用熔融共混法制备了C60−PEI/聚丙烯(PP)复合材料,并对其热性能和阻燃性能进行研究。热失重分析结果表明,C60−PEI可以更有效地发挥C60的自由基捕捉作用,对PP热稳定性的提高效果较C60更明显;氧化诱导测试(OIT)结果表明,C60−PEI/PP复合材料比C60/PP复合材料具有更优异的抗氧性能;微型量热测试也表明,燃烧过程中C60−PEI/PP复合材料比C60/PP复合材料具有更低的热释放量。Abstract: The hybrid of polyethyleneimine-decorated fullrene (C60−PEI) was synthesized by the addition reaction between active −NH− bonds in PEI and C=C bonds in C60 , and the molecular structure and morphology of C60−PEI were characterized by FTIR and TEM. The C60−PEI/polypropylene (PP) composite was prepared through the melt blending method and its thermal and flame retarded properties were studied. The thermogravimetric analysis results show that the thermal stability of the C60-PEI/PP composite is significantly higher than the C60/PP composite, because C60−PEI can play the radical capture role of C60 more effectively. The oxidation induced test (OIT) results show that the C60−PEI/PP composite has higher anti-oxidative ability than the C60/PP composite; the micro-calorimeter results also show that the heat release of the C60−PEI/PP composite is obviously lower than the C60/PP composite.
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Key words:
- fullerene(C60) /
- trapping radicals /
- thermo-oxidative stability /
- oxidation /
- polypropylene(PP) /
- composites
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表 1 富勒烯/聚丙烯(C60/PP)和C60-聚乙烯亚胺(PEI)/PP复合材料的配方
Table 1. Composition of fullrene/polypropylene(C60/PP) and C60-polyethyleneimine(PEI)/PP composites
Sample PP 1C60/PP 2C60/PP 3C60/PP 1C60-PEI/PP 2C60-PEI/PP 3C60-PEI/PP (3C60+PEI)/PP PP/wt% 100 99 98 97 99 98 97 97 C60/wt% — 1 2 3 — — — 2.75 C60-PEI/wt% — — — — 1 2 3 — PEI/wt% — — — — — — — 0.25 表 2 C60/PP和C60-PEI/PP复合材料空气气氛下的TG测试结果
Table 2. TG test results of C60/PP and C60-PEI/PP composites in air
Sample PP 1C60/ PP 2C60/PP 3C60/PP 1C60-PEI/PP 2C60-PEI/PP 3C60-PEI/PP (3C60+PEI)/PP Tonset/℃ 266.1 285.5 293.5 303.9 293.2 296.7 312.0 271.3 Tmax/℃ 381.2 397.8 400.0 417.5 399.2 404.6 427.5 396.8 Residue at 800oC/wt% 0.3 1.3 0.7 1.2 0.6 0 0 0.4 Notes: Tonset—Initial degradation temperature; Tmax—Maximum degradation temperature. 表 3 PP、3C60/PP、(3C60+PEI)/PP和3C60-PEI/PP复合材料180℃的OIT测试结果
Table 3. OIT test results of PP, 3C60/PP, (3C60+PEI)/PP and 3C60-PEI/PP composites at 180℃
Sample PP 3C60/PP (3C60+PEI)/PP 3C60-PEI/PP tmax/min 35.5 37.4 32.5 48.5 OIT/min 5.8 10.2 2.6 17.5 ΔH/(J·g−1) 6 119 5 176 5 088 3 909 Notes: tmax—Time corresponding to maximum oxidant speed; ΔH—Enthalpy. 表 4 PP、3C60/PP、(3C60+PEI)/PP和3C60-PEI/PP复合材料微型量热测试结果
Table 4. Micro-calorimeter test results of PP, 3C60/PP, (3C60+PEI)/PP and 3C60-PEI/PP composites
Sample PP 3C60/PP (3C60+PEI)/PP 3C60-PEI/ PP PHRR/(W·g−1) 1 176 1 003 1 173 880 THR/(kJ·g−1) 41.9 39.8 42.8 37.5 Tp/℃ 486 488 487 489 Notes: PHRR—Peak of heat release rate; THR—Total heat release; Tp—Temperature to PHRR. -
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