官能团化聚丙烯改性Mg(OH)2/PP的流动性

制备了官能团化聚丙烯(FPP)和丙烯酸(AA)改性Mg(OH)2/PP材料,用熔融指数仪研究了改性Mg(OH)2/PP流动性的影响。结果表明随Mg(OH)2加入及其含量增加,PP的熔体流动指数(MFI)明显降低。外加FPP可提高Mg(OH)2/PP的MFI值,而且在高Mg(OH)2含量时尤其明显。在Mg(OH)2/PP材料中加入AA更能提高材料的MI值,其作用比外加FPP的更大,归结于PP和AA存在增塑与润滑作用。而同时加入AA和DCP,由于DCP对PP的降解作用,使原位形成FPP改性材料的MFI值提高更加明显。     

丙烯酸改性卤锑阻燃PP的力学性能

在过氧化二异丙苯(DCF)存在或不存在条件下,制备了丙烯酸(AA)改性Sb2O3／聚丙烯(PP)母料、十溴联苯醚／PP母料及其相应的卤锑阻燃PP。研究了Sb2O3、十溴联苯醚和不同含量卤锑阻燃剂对PP力学性能的影响。结果表明,随Sb2O3含量增加,PP的拉伸和弯曲性能提高,缺口冲击强度降低。对于改性阻燃PP,无DCP时,加入AA有利于阻燃PP拉伸强度提高。但对其他力学性能影响不大。添加DCP提高了PP的弯曲强度。但AA用量高时,缺口冲击强度降低。AA改性阻燃PP的力学性能随着DCP用量增加而降低,尤其缺口冲击强度。退火处理使阻燃PP力学性能提高。     

丙烯酸改性卤锑阻燃聚丙烯的结晶性能

研究了丙烯酸(AA)改性Sb2O3,聚丙烯(PP)母料制备的不同用量卤锑阻燃PP。阻燃PP的差示扫描量热法结果表明,阻燃剂在PP中存在明显的异相成核作用,使PP结晶温度提高,Sb2O3对PP的异相成核作用比十溴二苯醚明显。在无引发剂过氧化二异丙苯(DCP)存在下,AA对阻燃PP中PP结晶温度的影响取决于阻燃剂的用量;在DCP存在下,PP的结晶温度不随AA用量增加而改变。DCP用量增加导致PP严重降解,结晶温度与熔融温度降低。     

聚丙烯改性无卤阻燃复合材料的研究

以聚丙烯(PP)为基材,探讨了不同用量的氢氧化镁(Mg(OH)_2)、微胶囊化红磷(MRP)对PP阻燃性能和力学性能的影响。实验结果表明:随着Mg(OH)_2用量的增加,PP/Mg(OH)_2复合材料的阻燃性能随之升高而力学性能下降。当Mg(OH)_2与MRP复配使用时,MRP的加入可减少Mg(OH)_2的用量,PP/Mg(OH)_2/MRP(100:100:12)与PP/Mg(OH)_2(100:150)的复合材料相比可以看出,拉伸强度、断裂伸长率、冲击强度分别提高了23.73%、38.52%、189%,表明Mg(OH)_2和MRP在PP无卤阻燃复合材料中具有很好的协效阻燃作用。相容剂PP-g-MAH的加入可以提升PP无卤阻燃复合材料的力学性能,PP-g-MAH用量为8份时,PP无卤阻燃复合材料的冲击强度和拉伸强度分别可达4.23kJ/m~2和25.6MPa,同时拥有良好的阻燃性能和加工性能。     

超细氢氧化镁粉的表面改性及其高填充聚丙烯的性能研究

使用铝酸酯对氢氧化镁超细粉进行了表面改性试验；将活化后的氢氧化镁添入PP材料中，研究了铝酸酯改性对PP/Mg(OH)2复合材料性能的影响；通过对改性前后的粉体进行SEM分析、FFIR分析以及对填充PP材料新鲜断面的SEM分析，研究铝酸酯偶联剂改性氢氧化镁粉的效果和改性机理。结果表明：铝酸酯的最佳用量为Mg(OH)2质量的2.0％，改性温度应为80℃；改性可以使PP/Mg(OH)2材料的悬臂梁缺口冲击强度提高一倍以上、弯曲模量提高30％以上，并使材料的UL94阻燃等级提高一个等级，但不能提高拉伸强度、弯曲强度和断裂伸长率.     

氢氧化镁表面处理工艺对阻燃PP性能的影响

为改善氢氧化镁[Mg(OH)2]与聚丙烯(PP)的相容性，将来源不同的两种Mg(OH)2进行表面处理后加入PP中，并对其表面性能、阻燃性能和力学性能进行了测试。结果表明，PP中添加占复合材料总质量65％的Mg(OH)2，其阻燃级别能达到V-0级，氧指数接近30％；且改性后的Mg(OH)2能大大改善阻燃PP的力学性能。同时通过比较不同偶联剂和处理方法对包覆效果的影响，选出了Mg(OH)2表面处理的较优工艺。     

双单体改性对纳米CaCO3/PP结晶与熔融行为的影响

制备了界面改性纳米CaCO3／PP复合材料，用DSC研究了在有、无过氧化二异丙苯(DCP)存在下，反应单体丙烯酸(AA)及苯乙烯(St)对PP结晶与熔融行为的影响。结果表明：AA改性纳米CaCO3／PP可使结晶温度提高；St改性使纳米CaCO3／PP的结晶温度降低，但在DCP存在下结晶温度反而提高。AA和St双单体改性使纳米CaCO3／PP的结晶温度明显降低，但加有DCP的双单体改性却使纳米CaCO3／PP的结晶温度大幅提高，说明双单体接枝物有促进纳米CaCO3表面成核的作用。     

表面改性方法对PP/Mg(OH)2无卤阻燃体系性能的影响

以聚丙烯(PP)为基体树脂,加入采用不同表面改性方法处理的氢氧化镁[Mg(OH)2]制备无卤阻燃PP复合材料。探讨了化学法和辐射法对PP/Mg(OH)2无卤阻燃复合材料阻燃性能和力学性能的影响。结果表明,用烷烃类偶联剂Ao-03进行表面改性的PP/Mg(OH)2具有较好的阻燃性能和力学性能,氧指数可以达到23.8%;拉伸强度变化不大,断裂伸长率达20%,是未处理PP/Mg(OH)2的9.5倍;冲击强度也最高,为未处理PP/Mg(OH)2的7倍。     

PP/Al(OH)_3/Mg(OH)_2/ZB复合材料阻燃性能的研究

测试了PP/Al(OH)3/Mg(OH)2/ZB、PP/Al(OH)3/Mg(OH)2/ZB/CaCO3和PP/Al(OH)3/Mg(OH)2/ZB/CaCO3/POE复合材料的阻燃性能。结果表明:随着阻燃剂用量的增加,氧指数升高,而燃烧速率和烟密度下降,且阻燃剂的加入对延缓燃烧速率的作用效果十分显著;相同配方下试件越厚燃烧速度越慢,且随阻燃剂用量的增加,试件越厚燃烧速率下降的幅度越慢;纳米CaCO3及POE的加入可以增大氧指数,降低烟密度,有利于阻燃,但同时也会使水平燃烧速率略微增大。     

PP无卤阻燃复合材料性能研究

采用双辊塑炼机制备了不同组分的聚丙烯(PP)无卤阻燃复合材料。利用差示扫描量热仪(DSC)、偏光显微镜(POM)和扫描电子显微镜(SEM)研究了Mg(OH)2、乙烯-辛烯共聚物(POE)、相容剂PP-g-MAH对PP无卤阻燃复合材料的热行为、结晶形态和微观结构的影响。结果表明:Mg(OH)2和POE两种成核剂的异相成核作用提高了共混物中PP的结晶温度和结晶速率;Mg(OH)2的加入使球晶颗粒变得细小且有碎晶产生;POE大分子链使PP分子链的扩散和堆积受阻,阻碍了晶粒的生长,从而导致PP/Mg(OH)2/POE复合材料结晶度的降低。PP-g-MAH的加入可以提高PP与Mg(OH)2的界面相容性,当PP/Mg(OH)2/POE/PP-g-MAH的配比为80/100/20/2时,PP无卤阻燃复合材料可以同时拥有良好的力学性能和阻燃性能。     

Crystallization and melt behavior of Mg(OH)2/PP composites modified by functionalized polypropylene

The crystallization and melting behavior of Mg(OH)₂/PP composites modified by the addition of functionalized polypropylene (FPP) or acrylic acid (AA) and the formation of in situ FPP were investigated by DSC. The results indicated that addition of FPP increased the crystallization temperatures of PP because of the nucleation effect of FPP. The formation of in situ FPP resulted in a reduced crystallization rate, melting point, and degree of crystallization attributed to the decreased regularity of the PP chain. For Mg(OH)₂/PP composites, the addition of Mg(OH)₂ increased the crystallization temperatures of PP resulting from a heterogeneous nucleation effect of Mg(OH)₂. The addition of FPP into Mg(OH)₂/PP composites further enhanced the crystallization temperatures of PP. It is suggested that there is an activation of FPP to the heterogeneous nucleation effect on the Mg(OH)₂ surface. The addition of AA also increased the crystallization temperatures of PP in Mg(OH)₂/PP composites, although the crystallization temperature of PP was not influenced by the AA content, which is explained by the heterogeneous nucleation effect of the Mg(OH)₂ surface activated by FPP and AA. A synergistic effect on the crystallization of PP in Mg(OH)₂/PP composites further increased the crystallization temperatures of PP. However, The crystallization temperatures of Mg(OH)₂/PP composites modified by in situ FPP were lower than those of Mg(OH)₂/PP composites modified by addition of either FPP or AA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3610–3621, 2004     

Crystallization and melt behavior of magnesium hydroxide/polypropylene composites modified by functionalized polypropylene

The crystallization and melting behavior of Mg(OH)₂/polypropylene (PP) composites modified by the addition of functionalized polypropylene (FPP) or acrylic acid (AA) and the formation of in situ FPP were investigated by DSC. The results indicated that addition of FPP increased crystallization temperatures of PP attributed to the nucleation effect of FPP. The formation of in situ FPP resulted in a reduced crystallization rate, melting point, and degree of crystallization because of the decreased regularity of the PP chain. For the Mg(OH)₂/PP composites, addition of Mg(OH)₂ increased the crystallization temperatures of PP attributed to a heterogeneous nucleation effect of Mg(OH)₂. Addition of FPP into Mg(OH)₂/PP composites further enhanced the crystallization temperatures of PP. It is suggested that there is an activation of FPP to the heterogeneous nucleation effect of Mg(OH)₂ surface. The addition of AA also increased the crystallization temperatures of PP in Mg(OH)₂/PP composites, but crystallization temperatures of PP were not influenced by the AA content, a phenomenon explained by the heterogeneous nucleation effect of the Mg(OH)₂ surface activated by FPP and AA. A synergistic effect on crystallization of PP in Mg(OH)₂/PP composites further increased the crystallization temperatures of PP. However, the crystallization temperatures of Mg(OH)₂/PP composites modified by in situ FPP were lower than those of Mg(OH)₂/PP composites modified by the addition of FPP or AA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91:3899–3908, 2004     

Mechanical properties of Mg(OH)2/polypropylene composites modified by functionalized polypropylene

Modified Mg(OH)₂/polypropylene (PP) composites were prepared by the addition of functionalized polypropylene (FPP); and acrylic acid (AA) and by the formation of in situ FPP. The effects of the addition of FPP and AA and the formation of in situ FPP on the mechanical properties of Mg(OH)₂/PP composites were investigated. Experimental results indicated that the addition of Mg(OH)₂ markedly reduced the mechanical properties of PP. The extent of reduction in notch impact strength of PP was higher than that in flexural strength and tensile strength. However, tensile modulus and flexural modulus increased with increased Mg(OH)₂ content. The addition of FPP facilitated the improvement in the flexural strength and tensile strength of Mg(OH)₂/PP composites. The higher the Mg(OH)₂ content was, the more significant the effect of FPP was. The incorporation of AA resulted in further increased mechanical properties, in particular the flexural strength, tensile strength, and notch impact strength of Mg(OH)₂/PP composites containing high levels of Mg(OH)₂. It not only improved mechanical properties but also increased the flame retardance of Mg(OH)₂/PP composites. Although the mechanical properties of composites modified by the formation of in situ FPP were lower than those of composites modified by only the addition of AA in the absence of diamylperoxide, the mechanical properties did not decline with increased Mg(OH)₂ content. Moreover, the mechanical properties increased with increasing AA content. The addition of an oxidation resistant did not influence the mechanical properties of the modified Mg(OH)₂/PP composites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2139–2147, 2003     

Fracture morphology of Mg(OH)2/polypropylene composites modified by functionalized polypropylene

The morphologies of the fracture surface under impact and flexural testing of Mg(OH)₂/Polypropylene (PP) composites and their modified composites were investigated by scanning electron microscopy. Experimental results indicated that addition of functionalized polypropylene (FPP) and acrylic acid (AA) and the formation of in situ FPP changed the fracture morphologies of Mg(OH)₂/PP composites. We believe that addition of these modifiers improved the interfacial interaction and enhanced the interface adhesion between the particle and the matrix in Mg(OH)₂/PP composites. The degree of improvement was more significant in Mg(OH)₂/PP composites modified by the formation of in situ FPP. At low Mg(OH)₂ content, 2 phr AA exhibited a marked effect, but at high Mg(OH)₂ content, 4 phr AA afforded good effect. Due to the improved interface adhesion by interface interactions the fracture mechanism transformed from interface debonded fracture into a matrix fracture. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2148–2159, 2003     

Thermal properties and flame retardance of Al(OH)3/polypropylene composites modified by polypropylene grafting with acrylic acid

The effect of polypropylene grafting with acrylic acid, PP‐g‐AA (FPP), on crystallization and melting behavior, thermal degradation, and limiting oxygen index of Al(OH)₃/PP composites were investigated. The results indicated that crystallization temperature of PP shifted to high temperature with increasing content of Al(OH)₃ because of the interfacial heterogeneous nucleation of Al(OH)₃ and further increased by the addition of FPP and with increasing FPP content because of the improvement of the dispersion of Al(OH)₃ in PP matrix and the increase in the nucleating sites of Al(OH)₃. With adding Al(OH)₃ and increasing the content of Al(OH)₃, limiting oxygen index values of composites increased and further improved by adding FPP. This is attributed to the presence of an interfacial interaction between FPP and Al(OH)₃. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2679–2686, 2001     

Properties of Chitosan-Filled Polypropylene (PP) Composites: The Effect of Acetic Acid

The main objective of this research was to investigate the effect of chitosan content and chemical modification with acetic acid on mechanical and thermal properties of PP/Chitosan. It was found that the tensile strength, elongation at break and crystallinity of untreated PP/Chitosan composites decreased with increasing filler content; however, Young's modulus and thermal stability increased. The treated chitosan with acetic acid have improved the tensile strength and Young's modulus of PP/Chitosan composites. The thermal analysis results show that chemical modified chitosan had increase thermal stability and crystallinity of treated PP/Chitosan composites. The scanning electron microscopy (SEM) study of the tensile fracture surface of treated PP/Chitosan composites indicated that the presence of acetic acid increased the interfacial interaction between chitosan and polypropylene matrix.     

Mechanical properties and fracture morphology of Al(OH)3/polypropylene composites modified by PP grafting with acrylic acid

Al(OH)₃/polypropylene (PP) composites modified by polypropylene grafted with acrylic acid (FPP) were prepared by melt extrusion. Effect of PP grafting with acrylic acid on mechanical properties and fracture morphology of Al(OH)₃/polypropylene composites were investigated. Although incorporation of Al(OH)₃ reduced the mechanical properties of PP, addition of FPP increased the mechanical properties of Al(OH)₃/PP composites. It is suggested that addition of FPP improve the dispersion of Al(OH)₃ and the interfacial interaction between filler and matrix. Mechanical properties of Al(OH)₃/FPP/PP composites depend on the grafting rate and the content of FPP. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2617–2623, 2001     

改性高岭土/聚丙烯复合材料的热性能及非等温结晶行为研究

以自制的剥离高岭(MK)、原高岭土(K)以及聚丙烯(PP)和马来酸酐接枝聚丙烯(PP-g-MA)等作为基本原料,通过熔融挤出、注塑成型,制备PP复合材料。采用XRD、DSC、TG研究复合材料的非等温结晶行为、结晶动力学以及热降解性能。结果表明:高岭土的加入,使结晶温度、结晶度、热稳定性都有所提高,且结晶速率加快,具有异相成核作用。与原高岭土相比,改性高岭土更能促进PP复合材料的PP异相成核,促进PP稳态晶型(α晶型)的转变,结晶速率较快。与纯PP和PP/PP-g-MA复合材料相比,PP/改性高岭土复合材料的结晶峰温度、最大热降解温度分别提高了16.7、7.8、9.7、12.6℃。     

反应性相容剂的制备及其在PP/玻璃纤维复合材料中的应用

以马来酸酐(MAH)为接枝单体、丙烯酸-2-羟乙酯为共聚单体,利用熔融接枝技术对聚丙烯(PP)进行改性;以MAH/丙烯酸-2-羟乙酯熔融接枝改性PP为相容剂,研究相容剂对PP/玻璃纤维复合材料结构和性能的影响。结果表明:与未接枝PP相比,熔融接枝PP分子上接枝了MAH和—OH基团,而且熔融接枝反应对PP的熔点和热稳定性具有明显影响。另外,随着接枝PP含量的增加,PP/玻璃纤维复合材料的力学性能明显改善。当接枝PP含量为15%时,复合材料的拉伸强度提高了32%,冲击强度提高了13%,表明采用熔融共接枝工艺制备的PP具有优良的增容、偶联和分散效果。     

Physical and mechanical properties of Al(OH)3/polypropylene composites modified by in situ‐functionalized polypropylene

Al(OH)₃/polypropylene (PP) composites modified by in situ‐functionalized polypropylene (FPP) were prepared by a one‐step melt‐extrusion process. The effect of in situ FPP on the crystallization and melting behavior, melt‐flow index, limiting oxygen index, thermal degradation, mechanical properties, and fracture morphology of Al(OH)₃/PP composites was studied. Formation of in situ FPP resulted in a decreased crystallization temperature and melting point of PP in the composites, an increased melt‐flow index, and improved tensile and flexural strengths of Al(OH)₃/PP composites, whereas the thermal degradation behavior and limiting oxygen index was not been influenced. The impact strength of the Al(OH)₃/PP composites modified by in situ FPP depended upon the content of the initiator, dicumyl peroxide, and the monomer, acrylic acid. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2850–2857, 2002; DOI 10.1002/app.10269