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为了应对聚丙烯(PP)普遍存在的韧性不足的缺点,研究了纳米碳酸钙(nano-CaCO3)对PP力学性能、结晶行为和微观结构的影响,并探讨了nano-CaCO3对PP的增韧机理。结果表明:nano-CaCO3对PP具有良好的增韧效果,当w(nano-CaCO3)为35%时,复合材料的室温(23℃)冲击强度最大,为2.43 kJ/m2,较纯PP提高了26.4%,但nano-CaCO3含量较高时,复合材料的冲击强度急剧下降。通过透射电子显微镜发现,高填充的纳米颗粒在PP基体中发生团聚,在应力作用下刚性填料与基体界面出现应力集中和剥离,破坏了原有纳米颗粒的增韧效果。 相似文献
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纳米碳酸钙增韧增强聚丙烯的研究 总被引:6,自引:0,他引:6
研究了聚丙烯/纳米碳酸钙复合材料的综合力学性能,用Ceast仪器化冲击试验机对复合材料冲击过程的力一时间、能量一时间关系曲线分析表明,冲击裂纹开裂应力和开裂能都远高于橡胶或弹性体增韧聚丙烯体系,证明该复合材料是一类“强而韧”的材料;用扫描电镜观察复合材料缺口冲击祥条断面发现,复合材料的断裂方式由耗能少的空洞化一银纹断裂方式逐步向耗能多的基体屈服方式转化,从而达到材料的增韧。 相似文献
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聚合物原位复合纳米碳酸钙增韧PP研究 总被引:6,自引:0,他引:6
通过有机单体原位聚合包覆的CaCO3与PP熔融混合制备了PP/CaCO3纳米复合材料,经过正交实验研究了填料饱覆聚合物比、接枝聚丙烯以及复合填料含量对PP缺口冲击强度的影响,结果表明:复合纳米CaCO3只需填加5%就可以将缺口冲击强度提高为原树脂的2倍左右。 相似文献
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进行了碳酸钙对聚丙烯(PP)的填充改性研究,结果表明:随1%(质量分数)钛酸酯偶联剂表面处理的碳酸钙用量增加,PP/碳酸钙复合材料的拉伸强度、弯曲强度、弯曲模量等逐渐增加,碳酸钙质量分数为20%时,得到了综合性能较好的PP/碳酸钙复合材料;随聚烯烃弹性体(POE)用量增加,PP/碳酸钙/POE复合材料的冲击强度逐渐增加,而拉伸强度、弯曲模量均逐渐降低,5份POE使复合材料达到较好的刚性和韧性的平衡;1份表面光亮剂能使PP/碳酸钙复合材料达到较好的表面光亮度. 相似文献
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纳米级CaCO3粒子增韧增强聚丙烯的研究 总被引:97,自引:11,他引:97
通过对纳米级CaCO3粒子进行表面预处理和熔融共混工艺制备了PP/纳米CaCO3复合材料,并进行了力学测试和结构表征。结果表明,经过适当表面处理的纳米CaCO3粒子可以通过熔融共混法均匀分散在聚然中,粒子与基体界面结合良好,纳米CaCO3粒子在低于10%用量时即可使聚丙烯缺口冲击强度提高3~4倍,同时基本保持其拉伸强度和刚度。DSC熔融曲线分析表明,CaCO3对聚丙烯的β晶结晶过程有明显的诱地作用 相似文献
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碳酸钙晶须制备及其对聚丙烯的改性 总被引:1,自引:0,他引:1
研究了碳酸钙(CaCO3)晶须的制备方法,探索了以氯化镁(MgCl2)为促进剂时CaCO3晶须生长的影响因素,试验得到了制备CaCO3晶须的最佳条件。采用红外光谱、拉曼光谱等对CaCO3晶须结构进行了性能和结构表征,发现所制备的产物中晶须含量达97%(质量分数),长径比(L/D)为20~30。探讨了所制晶须对聚丙烯(PP)材料改性的效果,结果表明,晶须改性PP的力学性能、流动性明显优于普通重质CaCO3填充PP的。与纯PP相比,在填充量15%(质量分数)的情况下,CaCO3晶须改性的PP,其拉伸断裂强度提高35.7%,弯曲模量提高117%,冲击强度提高31.5%,熔体流动速率基本不下降。 相似文献
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PP/纳米CaCO3复合材料的抗冲击性能 总被引:7,自引:0,他引:7
对纳米CaCO3采用脂肪酸处理和钛酸酯偶联剂处理,分别制备了聚丙烯,纳米CaCO3复合材料(SⅠ)和(SⅡ),考察了不同处理方法和纳米CaCO3含量对复合材料抗冲击性能的影响。结果表明,随着妒(CaCO3)的增加,试样的V形和U形缺口冲击强度有所提高;当ψ(CaC03)大于1.0%后,SⅡ的V形缺口冲击强度明显高于SⅠ,而表面处理对U形缺口冲击强度的影响不太明显。 相似文献
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PP/针形纳米CaCO3复合材料的力学性能 总被引:1,自引:0,他引:1
用硬脂酸皂化改性针形纳米CaCO3表面后,将其与聚丙烯(PP)共混、挤出和注塑,制成PP/CaCO3纳米复合材料。与纯PP相比,填充针形纳米CaCO3的体积分数为4.21%时,PP体系的冲击强度和断裂伸长率分别提高了49%,339%,拉伸强度下降2.7%。改性后的纳米CaCO3与PP之间的界面作用与改性前相比有所减弱,冲击断面扫描电子显微镜照片显示,针形纳米CaCO3均匀地分散在PP基体中。偏光显微照片显示,针形纳米CaCO3对PP有明显的异相成核作用。 相似文献
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The mechanisms of deformation and fracture of isotactic polypropylene filled with CaCO3 particles were studied. Three types of particles with average diameters of 0.07, 0.7, and 3.5 μm were used at filler volume fraction from 0.05 to 0.30. The experiments included slow tensile tests, notched Izod impact tests with varying notch depths, and fracture resistance tests using double-cantilever-beam sample configurations. In slow tension, addition of fillers increased the modulus and decreased the yield stress independently of filler type. The strain at break increased with initial incorporation of fillers but decreased at higher loadings. The 0.7 μm diameter particles improved Izod impact energy up to four times that of the unfilled matrix. The other particles had either adverse or no effect on the impact toughness. The toughening mechanisms at work were plastic deformation of interparticle ligaments following particle-matrix debonding with additional contribution coming from crack deflection toughening. The failure of the 0.07 and 3.5 μm diameter particles to toughen the matrix was attributed to poor dispersion. 相似文献
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针状纳米级碳酸钙的工业生产与应用 总被引:3,自引:0,他引:3
经小试、中试(70 t/a装置)、工业化试验(25 kt/a工业装置),在自研的多组分结晶导向剂的作用下,较高温度(35~75℃)、较高浓度(7%~12%)碳化工艺条件下合成粒度分布均匀,粒径为10~20 nm,长径比为15~20,比表面积≥90 m2/g,总孔容≥0.26 cm3/g的针状(晶须)纳米碳酸钙。经在乳胶漆、PVC制品中试用,均取得理想效果。文中还给出了10 kt/a针状(晶须)纳米级碳酸钙新建与改建设计方案。 相似文献
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The multiple melting-peak behavior of polypropylene (PP) in nano-CaCO3/PP composites and modified nano-CaCO3/PP composites were investigated under the condition of isothermal crystallization and nonisothermal crystallization. The
result indicated that the addition of nano-CaCO3 markedly increased the crystallization temperatures of PP and induced the formation of the β-crystal of PP. The crystallization
temperatures of nano-CaCO3/PP composites modified by reactive monomers were further increased, but the melting-peak intensity of the β-crystal of PP
was not greatly influenced. While in the presence of dicumyl peroxide, nano-CaCO3/PP composites modified by reactive monomers led to the significant increase in the melting-peak intensity of the β-crystal
of PP. The double melting-peak of PP was observed, which was attributed to the formation of two kinds of different crystallization
forms of α-crystal or β-crystal during the crystallization of PP. With the increase of crystallization temperatures, the double
melting-peak moved toward the high-temperature side. The intensity of high-temperature melting peak was higher than that of
low-temperature melting peak in nano-CaCO3/PP composites. While in modified nano-CaCO3/PP composites crystallized at higher temperature, the intensity of high-temperature melting peak was lower than that of low-temperature
melting peak. The isothermal crystallization time had little effect on the melting temperatures.
Translated from Acta Scientiarum Naturalium Universitatis Sunyatseni, 2006, 45(2): 41–45 [译自: 中山大学学报 (自然科学版)] 相似文献