硬石膏/聚丙烯复合材料的性能研究

研究了硬石膏及其表面改性对聚丙烯(PP)复合材料的力学性能、球晶尺寸、熔点和结晶度的影响.结果表明硬石膏能够增韧增强PP,经铝酸酯偶联剂改性的硬石膏的增韧增强效果比不改性更加明显;硬石膏的加入使得球晶尺寸减小,数量增加.硬石膏的加入可提高复合材料的熔点.同样填充量下改性剂的使用会降低复合材料的熔点,提高PP的结晶度.     

聚丙烯/纳米TiO2复合材料的性能研究

研究了PP／纳米TiO2、PP／普通TiO2复合材料的流变行为、力学性能和抗菌性能。结果表明：在PP中加入TiO2后，熔体的表观粘度增大，PP／纳米TiO2复合材料尤其明显；熔体流变性对温度的敏感性降低，PP的加工温度范围变宽。纳米TiO2对PP的增韧作用比普通TiO2更好，在0-4％的范围内，材料的冲击强度随用量的增加而增大；而对材料拉伸性能的影响甚微。PP／纳米、普通TiO2复合材料都是有抗菌作用，PP／纳米TiO2的抗菌作用相对较强。     

聚丙烯/蒙脱土纳米复合材料流变性能的研究

采用毛细管流变仪研究了聚丙烯(PP)／蒙脱土纳米复合材料的流变性能。结果表明：PP／蒙脱土纳米复合材料的流动特性与常规PP相似，为典型的假塑性流动；其非牛顿指数随温度提高而增大，在220℃时，复合材料的非牛顿性小于PP，在260℃时，复合材料的非牛顿性大于PP；复合材料的表观粘度低于PP，粘流活化能大于PP。     

PP/PVAc-OMMT纳米复合材料流变行为的研究

借助HAAKE RHEOCORD 90 流变仪分别在180,190和200℃3个温度下,研究了聚丙烯(PP)和PP/聚醋酸乙烯酯有机蒙脱土(PVAc-OMMT)纳米复合材料的流变行为.结果表明:PP/PVAc-OMMT纳米复合材料的熔体流动行为同PP一样,仍属于非牛顿型假塑性流体流动行为,剪切应力对纳米复合材料中OMMT含量变化敏感;恒温下随着OMMT含量的增加,纳米复合材料的表观粘度增加;PVAc-OMMT的加入明显减弱了PP表观粘度对温度变化的敏感程度; 相同温度下,PP/PVAc-OMMT纳米复合材料挤出膨胀比低于PP的,这一特性说明PP/PVAc-OMMT纳米复合材料制品尺寸稳定性较PP有所提高.     

接枝丙烯酸对SF/PP复合材料性能的影响

分别对短切剑麻纤维(SF)和聚丙烯(PP)进行接枝丙烯酸(AA)预处理后，采用片状层压工艺制备了SF／PP、SF／PP-g-AA、SF-g-AA／PP复合材料；测试了复合材料的力学性能，并观察了复合材料的断面形态。结果表明：SF／PP-g-AA复合材料的综合力学性能比SF／PP复合材料有明显提高，而SF-g-AA／PP复合材料的综合力学性能反而比SF／PP复合材料差。     

PP/LCP原位复合材料微观结构与结晶性能的研究

分别用SEM、TEM和XRD对不同温度、不同压延率的PP／LCP复合材料的微观结构和结晶状况等进行研究。结果发现，PP／LCP复合材料经过高温、室温压延后仍存在皮芯结构；温度和压延率的提高促进了LCP微纤的形成和长大，增强了PP相和LCP相的结合力；PP相和LCP相都有结晶生成，压延率的提高降低了材料的结晶度，温度的提高减小了结晶度降低的幅度。     

原位反应法聚丙烯/蒙脱土复合材料的制备、结构与性能Ⅱ.热分析与流变行为

利用TGA、DSC和RAD-3型高级应变控制流变仪对原位反应增容技术制备的聚丙烯／蒙脱土(PP／MMT)复合材料的熔融与结晶行为、热稳定性能和流变性能进行了系统的研究。热分析结果表明，PP／MMT复合材料的熔融热焓显著降低，结晶度明显提高，在整个热分解温度范围内的耐热稳定性比纯PP差，说明MMT可显著提高该复合材料的阻燃特性，在PP的结晶过程中起到异相成核作用。流变行为的结果表明，PR／MMT复合材料为假塑性熔体，加工行为与PP相似，其储存模量、损耗模量、表观粘度和扭矩等流变参数随MMT的加入显著降低，表明MMT的加入不会损害：PP／MMT复合材料的加工流动性，反而可改善其加工性能。     

聚丙烯／热致液晶聚合物／玻璃纤维混杂复合材料的制备及性能研究

提出了一种制备原位混杂复合材料的新途径。将聚丙烯(PP)、热致液晶聚合物(TLCP)与玻璃纤维(GF)在高于TLCP熔点的温度下熔融共混挤出，经适当拉伸，然后造粒，得到TLCP成纤良好的PP／TLCP／GF复合材料粒料。将其在不同温度下注射成型，考察了成型温度对所得混杂复合材料中TLCP组分的形态及材料力学性能的影响。结果表明，注射成型温度对最终复合材料中TLCP形态及材料的力学性能有明显的影响。当注射温度为200℃和220℃，即低于TLCP的熔融温度较多时，所得混杂复合材料中TLCP组分保持了较好的微纤结构，复合材料具有良好的力学性能。注射成型温度为240℃时，复合材料中TLCP相开始出现熔融回缩；而当加工温度高于260℃后，TLCP分散相主要成球形。随注射成型温度升高，混杂复合材料的力学性能逐渐下降。在基体中加入聚丙烯接枝马来酸酐(PP-g-MAH)作为增容剂，可以同时改善PP与TLCP、PP与GF之间的界面黏结，从而有利于混杂复合材料力学性能的提高。     

聚丙烯/纳米TiO2复合材料的紫外老化研究

对聚丙烯(PP)／纳米TiO2复合材料的紫外老化进行了研究。力学性能、熔体粘度、熔融温度、红外光谱和扫描电镜对比试验的结果表明：PP／纳米TiO2复合材料的耐紫外老化性能比纯PP的大大提高,纳米TiO2是一种性能优异的PP抗老化剂。     

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。     

Performance of long glass fiber‐reinforced polypropylene composites at different injection temperature

Long glass fiber‐reinforced polypropylene composites were prepared using self‐designed impregnation device. Effects of the different injection temperature on mechanical properties, crystallization, thermal, and dynamic mechanical properties of long glass fiber‐reinforced polypropylene composites were discussed. The differential scanning calorimetry (DSC) results indicate that the melting peak temperature of PP/LGF composites gradually reduced, however, the crystallinity of PP/LGF composites gradually increased with increasing injection temperature. Thermo‐gravimetric analyzer (TGA) results demonstrate that with increasing injection temperature, the temperature of the PP/LGF composites melt increased, the viscosity of the PP/LGF composites melt lowered, the mold filling of the PP/LGF composites melt was easy, the shear force of glass fiber was relatively low, which made the residual length of glass fiber in products increase. Dynamic thermal mechanical analyzer (DMA) results show that the storage modulus of PP/LGF composites is the highest while the injection temperature is at 290°C, and the peak value of tan σ of PP /LGF composites at 290°C is minimal, which indicates that the mechanical properties of PP /LGF composites at 290°C is the best. What' more, the injection temperature at 290°C significantly ameliorated “glass fiber rich skin” of products of glass fiber‐reinforced composites. J. VINYL ADDIT. TECHNOL., 24:233–238, 2018. © 2016 Society of Plastics Engineers     

Crystallization,melting behavior,and crystal structure of reactive,intumescent, flame‐retardant polypropylene

Polypropylene (PP)/2‐({9‐[(4,6‐diamino‐1,3,5‐triazin‐2‐yl) amino]‐3,9‐dioxido‐2,4,8,10‐tetraoxa‐3,9‐diphosphaspiro [5.5] undecan‐3‐yl} oxy) ethyl methacrylate (EADP) composites were prepared by the blending of PP with EADP as a new flame‐retardant material. The nonisothermal crystallization and melting behaviors of composites were investigated with differential scanning calorimetry (DSC). Their crystal morphologies and structures were studied by polarized optical microscopy (POM) and X‐ray diffraction (XRD), respectively. The DSC results show that the addition of EADP increased the crystallization onset temperature, crystallization peak temperature, and degree of crystallinity of PP in the PP/EADP composites. The melting onset temperature and melting end temperature of the PP/EADP composites decreased slightly, whereas the melting peak temperature of the PP/EADP composites increased. The POM results show that the addition of EADP greatly reduced the crystal size of PP in the composites. When the content of EADP in the PP/EADP composites was increased, the crystal size of PP became smaller. The XRD results indicate that the addition of EADP changed the crystal structure of PP in the PP/EADP composites, which exhibited both α‐form and β‐form crystal structures. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41374.     

稀土β晶成核剂改性nano-CaCO_3/PP复合材料的结晶行为

讨论了稀土β晶成核剂(WBGⅡ)对nano-CaCO3/PP复合材料结晶性能的影响,并借助WAXD、DSC及PLM对PP、nano-CaCO3/PP和WBGⅡ/nano-CaCO3/PP复合材料的结晶行为及晶体形态进行了表征。结果表明:加入少量WBGⅡ后,聚丙烯基复合材料的晶型和球晶形态发生明显变化,提高了材料的起始结晶温度和结晶温度,降低了材料的过冷度,半结晶期延长。     

聚丙烯基石墨烯改性复合材料的导电及热稳定性

以邻二氯苯（O-DCB）为溶剂,将超声预分散的石墨烯纳米微片（GNS）混入聚丙烯（PP）基材,再经塑化、热压成型获得GNS/PP复合材料。采用扫描电镜观察其微观形态变化,高阻计测量其电阻并计算出体积电阻率,同步热分析仪测试其在空气中的热稳定性能。结果表明,GNS在PP基材中分散均匀,并相互连接构成网络结构;GNS/PP复合材料的导电性能相较PP有了显著提升,当GNS质量含量为1%~2%时,复合材料出现明显的导电渗流现象,其体积电阻率降幅达6个数量级;当空气温度高于324℃时,在相同温度下,1% GNS/PP复合材料相较PP的失量更少,且整个失量阶段的温度跨度较PP提高40℃,但GNS的存在也导致GNS/PP复合材料的起始失量温度较PP提前30~40℃,并出现使材料完全失量的终点温度,且GNS质量含量越高,该终点温度越低。将低成本的GNS均匀掺入PP中能够获得导电性能优异并具备一定程度热稳定性的功能型复合材料。     

PP/PP-g-MAH/HGB复合材料非等温结晶行为研究

采用熔融法制备了聚丙烯/马来酸酐接枝聚丙烯/空心玻璃微珠（PP/PP-g-MAH/HGB）复合材料,采用差示扫描量热仪研究了PP、PP/HGB、PP/PP-g-MAH/HGB复合材料的非等温结晶过程,并通过Jeziorny法和Mo法研究了3种材料的非等温结晶动力学。结果表明,随着降温速率的增大,3种材料的结晶峰温、结晶起始温度和结晶度均减小,结晶速率增大;HGB抑制了PP的结晶行为,降低了结晶速率;PP-g-MAH对PP结晶速率的影响较小,HGB和PP-g-MAH都会改变PP的结晶成核和生长机理。     

PP/MRP复合材料熔体挤出胀大行为的研究

采用熔体流动速率仪考察了温度、剪切应力、以及微胶囊红磷(MRP)含量对聚丙烯(PP)/MRP复合体系熔体挤出胀大比的影响。结果表明:PP/MRP复合体系熔体的挤出胀大比随着温度的升高而呈减小的趋势,随剪切应力的增加而显著增大,并且在185℃时,挤出胀大比与剪切应力之间基本符合线性关系;MRP含量增大,则PP/MRP复合体系熔体的挤出胀大比值呈减小的趋势。     

玻纤增强茂金属聚乙烯弹性体改性聚丙烯的研究

采用短玻纤（SGF）对PP／茂金属聚乙烯弹性体（mPE）共混物进行增强,制得PP／mPE/SGF三元共混复合材料,分别对PP／mPE二元共混物和PP／mPE/SGF三元共混复合材料的力学性能进行了研究。探讨了弹性体用量、SGF的用量和表面处理对共混物和复合材料拉伸性能、低温冲击韧性和蠕变性能的影响。结果表明,PP／mPE/SGF三元共混复合材料同时具有良好的刚性和韧性。     

聚丙烯/微胶囊红磷复合材料熔体密度及流动性能研究

采用熔体流动速率仪考察了温度、载荷以及微胶囊红磷含量对聚丙烯/微胶囊红磷(PP/MRP)复合体系熔体密度和流动性能的影响。结果表明:在实验条件下,PP/MRP复合体系熔体密度随温度升高而降低,随载荷的增大而提高,随MRP含量的增加而呈增大的趋势。PP/MRP复合体系熔体的表观剪切应力与剪切速率基本符合幂律方程,熔体为假塑性流体,并且随着温度的升高,熔体黏度降低,假塑性增强;随着MRP含量的增加,熔体的黏度提高,假塑性增强。PP/MRP复合体系熔体的表观剪切黏度对温度的依赖性符合Arrhenius关系。     

Influence of ammonium polyphosphate modified with 3‐(methylacryloxyl) propyltrimethoxy silane on mechanical and thermal properties of wood flour–polypropylene composites

In this article, the influence of ammonium polyphosphate (APP) and ammonium polyphosphate modified with 3‐(Methylacryloxyl) propyltrimethoxy silane (M‐APP) on mechanical properties, flame retardancy, and thermal degradation of wood flour–polypropylene composites (WF/PP composites) have been investigated. Polypropylene grafted with m‐isopropenyl‐α,α‐dimethylbenzyl‐isocyanate (m‐TMI‐g‐PP) was used to improve the adhesion of WF/PP composites. APP and M‐APP were used as flame retardants. The experimental results demonstrated that addition of M‐APP obviously enhanced mechanical properties of WF/PP composites. According to cone calorimetry results, M‐APP is also an effective flame retardant for WF/PP composites, compared to that of APP. It was also found that M‐APP decreased the 1% weight loss temperature and increased char residue. The thermal degradation of wood flour based upon the first peak temperature of wood decreased from 329.3 to 322.9°C and the thermal degradation of PP based upon the second peak temperature of PP improve from 518.0 to 519.6°C, when M‐APP was added to the WF/PP composites. From SEM results the char layer of the 25% M‐APP systems is much more intumescent than that of the 25% APP systems, indicating that 3‐(Methylacryloxyl) propyltrimethoxy silane can improve the char‐forming ability of WF/PP composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011