SEBS-g-MAH对聚丙烯/氢氧化镁纳米复合材料微观结构与流变性能的影响

以马来酸酐接枝的SEBS(SEBS-g-MAH)作为界面改性剂制备了PP/SEBS-g-MAH/氢氧化镁(MH)纳米复合材料,采用SEM、DSC和毛细管流变仪研究了SEBS-g-MAH对复合材料的微观结构、结晶行为和流动性能的影响。结果表明,SEBS-g-MAH的加入充当了MH粒子与PP基体的界面层,提高了纳米MH粒子在PP中的均匀分散性,改善了两者的界面相互作用和PP/MH复合体系的流动性能。     

表面改性对聚丙烯/微米氢氧化镁复合材料性能的影响

研究了表面处理剂（钛酸酯和硅烷偶联剂）和原位聚合方法对聚丙烯/微米氢氧化镁（MH）复合材料的力学性能及流变性能的影响。采用DSC、SEM和毛细管流变仪对PP/MH（80/20）复合材料的性能进行了研究。结果表明：原位聚合改性后的微米MH与PP基体间的界面黏结力得到了加强,复合材料的冲击强度较填充未改性MH的复合材料提高了26.4 ％。在PP基体中添加聚合物包覆改性微米MH粒子的复合材料熔体流动速率较纯PP上升了64 ％。在相同剪切速率下,填充聚合物包覆改性MH的复合材料熔体表观黏度明显低于填充未改性微米MH的复合材料,表明聚合物包覆改性后的MH降低了其对PP熔体流动的阻碍作用,改善了PP/MH复合材料的流动性能。     

微晶纤维素增强聚丙烯复合材料的制备与力学性能研究

以聚丙烯(PP)为基体、微晶纤维素(MCC)为增强材料、马来酸酐接枝聚丙烯(PP-g-MA)为相容剂,利用双螺杆挤出机制备了PP/MCC/PP-g-MA复合材料,同时研究了该复合材料的力学性能。随后分别选用三元乙丙橡胶(EPDM)和乙烯-辛烯共聚物(POE)对PP/MCC/PP-g-MA复合材料进行增韧改性,考察了两种增韧剂的增韧效果。结果表明:加入PP-g-MA后,PP/MCC复合材料的力学性能明显提高。另外,增韧剂的引入使PP/MCC/PP-g-MA复合材料的冲击性能显著改善,其中POE对复合材料的增韧效果优于EPDM。但是增韧剂的引入会造成复合材料的拉伸强度、弹性模量和弯曲强度分别出现不同程度的下降,其中EPDM增韧复合材料的上述性能下降幅度相对较小。     

PP-g-MA和UP增容PP/玻璃纤维复合材料性能的研究

以聚丙烯-马来酸酐接枝(物PP-g-MA)和不饱和聚(酯UP)作为界面相容剂,研究了界面相容剂对玻璃纤维增强PP复合材料力学性能及界面黏结的影响。结果表明:加入PP-g-MA或UP,玻璃纤维增强PP复合材料的力学性能明显提高,且UP的增容效果优于PP-g-MA。在玻璃纤维含量为40%时,PP/UP/GF复合材料的拉伸强度比未改性的复合材料的拉伸强度提高了150%,弯曲强度提高了132%,冲击强度提高了89%;扫描电镜照片表明:PP-g-MA和UP使被拔出玻璃纤维表面黏附了一层树脂,增强了PP与玻璃纤维之间的界面黏结作用;DSC测试表明:PP-g-MA和UP同时加入使复合材料熔融峰温度下降结,晶度增加。     

聚丙烯及接枝物聚丙烯对尼龙6性能的影响

采用熔融共混法制备了聚丙烯/尼龙6(PP/PA6)和马来酸酐接枝聚丙烯/尼龙6(PP-g-MA/PA6)复合材料,用扫描电镜(SEM)和X射线衍射仪(XRD)观察表征了材料的形貌和结构,测试了材料的力学性能。研究表明:适量加入PP或PP-g-MA可提高PA6的抗冲性能,有利于PA6的α-晶型生长。与不相容PP/PA6共混物比较,PP-g-MA和PA6存在较强界面粘附,使PP-g-MA/PA6的冲击强度提高,同时保持较高拉伸、弯曲和压缩性能,PP-g-MA/PA6质量配比为10/90时,其综合性能较好。     

硬脂酸对纳米ZnO填充聚丙烯流变和结晶行为的影响

为了给纳米ZnO/聚丙烯(PP)复合材料的加工及性能优化提供理论依据,采用熔融共混的方式制备纳米ZnO/PP复合材料,通过扫描电子显微镜(SEM)、旋转流变仪、差示扫描量热仪(DSC)以及X射线衍射仪(XRD)对纳米ZnO/PP复合材料的结构与性能进行表征,以研究硬脂酸加入前后对复合材料的微观结构、流变性能及结晶行为的影响。结果表明,当纳米ZnO质量分数低于5%时,粒子分散良好,复合材料熔体的复数黏度随纳米ZnO质量分数的增大而减小,但是当纳米ZnO质量分数高于10%后,纳米粒子发生团聚,体系黏度上升。硬脂酸的加入增强了ZnO纳米粒子与PP基体的界面作用,也改善了ZnO纳米粒子的分散性。纳米ZnO质量分数小于5%时,对PP结晶没有明显影响,但是当纳米粒子团聚后对PP起异相成核作用。硬脂酸的加入可以有效抑制复合材料中的PP在升温过程中β晶向α晶的转变。ZnO纳米粒子的团聚对β晶的形成起抑制作用。     

有机硅改性剂对PP/Mg(OH)2复合材料结构和性能的影响

研究了有机硅改性剂对聚丙烯(Polypropylene, PP)和氢氧化镁(Magnesium Hydroxide,MH)复合材料的微观结构以及熔融流动性能和燃烧性能的影响.结果表明:在PP/MH复合体系中加入适量有机硅改性剂后,MH粒子的团聚程度显著降低,复合材料的微观组成更加均匀,熔融流动性能更好,水平燃烧级别下降,但对材料的氧指数影响不大.     

转速对PP-g-MA改性石墨烯/TPU/PP复合材料力学和电学性能的影响

以热塑性聚氨酯(TPU)和聚丙烯(PP)为基体,石墨烯为导电填料,聚丙烯接枝马来酸酐(PP-g-MA)为界面增容剂,制备了石墨烯/TPU/PP/PP-g-MA导电复合材料。研究了螺杆转速对复合材料力学性能和电学性能的影响以及石墨烯在复合材料中的选择性分布状态。结果表明,随着螺杆转速从10 r/min提高到50 r/min,复合材料的拉伸强度提高了103.62%,断裂伸长率提高了161.47%,电导率提高了155.49%,体系中石墨烯选择性分布在TPU中,石墨烯/TPU在基体中则形成了共连续的导电网络。     

反应性增容对PP/纳米SiO_2界面作用的影响

通过动态力学分析和拉伸性能的测试,采用不同模型研究了反应性增容对聚丙烯(PP),纳米SiO2复合材料界面作用的影响.研究表明,反应性增容使纳米SiO2粒子与PP基体的界面作用明显增强,使PP分子链的松弛活化能增大.在环氧功能化改性纳米SiO2粒子和反应性增容剂(氨基化PP)的质量分数分别为3%和10%时,复合材料的冲击强度从1.85 kJ/m2提高到3.46 kJ/m2,体现了明显的增韧作用.     

表面处理对TiO_2/PP复合材料界面的影响

采用硅烷偶联剂对TiO2 颗粒进行表面处理改性并与聚丙烯 (PP)共混填充。通过红外光谱分析和扫描电镜分析研究了表面处理对TiO2 /PP界面结合的改性效果 ,研究了表面处理对TiO2 /PP复合材料的流动性能的影响。研究结果表明 ,表面处理可以明显改善复合材料的流动性能、改善复合材料的界面结合效果     

The Effects of PP-g-MA on the Physical Properties and Morphology of Polypropylene (PP)/Recycled Acrylonitrile Butadiene Rubber (rNBR) Blends

Polypropylene-grafted maleic anhydride (PP-g-MA) was used to enhance the compatibility of polypropylene (PP) and recycled acrylonitrile butadiene rubber (rNBR) blends. The blends were prepared by melt mixing using a Haake Rheomix Polydrive R 600/610 mixer at 180°C. The processing torque was used to investigate the mixing process. The better mixing of compatibilized blends (PP/rNBR-MA) was evidence by the higher stabilization torque. Compared to uncomapatibilized PP/rNBR blends, tensile properties and oil resistance of compatibilized PP/rNBR were improved. SEM micrographs of tensile fractured surfaces showed better dispersion and better interfacial adhesion between the phases of compatibilized blends compared to uncompatibilized counterparts.     

废旧PU硬泡的降解及其与PP共混物的性能研究

采用二乙醇胺为降解剂对废旧聚氨酯(PU)硬泡进行降解处理,制备了降解PU/聚丙烯(PP)共混材料;研究了不同降解程度的PU硬泡对PU/PP/PP-g-MA共混材料性能的影响。结果表明:随着降解时间的增加,PU硬泡的凝胶的质量分数由91.4%下降到3.6%,降解产物的玻璃化转变温度由75℃下降到36℃;FTIR证明了降解产生了带有氨基和羟基基团的PU,这些基团成为反应增容的活性点;PU/PP/PP-g-MA复合材料的断裂伸长率由100%上升到1800%,SEM表明复合材料具有有良好的均匀性和相互作用。     

PP-g-MAH对SEBS/PP/MH/EG阻燃复合体系结构与性能的影响

在氢氧化镁(MH)与可膨胀石墨(EG)复配阻燃石蜡油改性苯乙烯-乙烯/丁烯-苯乙烯(SEBS)/聚丙烯(PP)共混物(O-SEBS/PP)体系中,用马来酸酐接枝聚丙烯(PP-g-MAH)增容,研究其对O-SEBS/PP/MH/EG阻燃复合体系结构和性能的影响。结果表明:以一定量的PP-g-MAH代替基体中的PP增容后,复合材料在保持UL94垂直燃烧V-0级的同时,拉伸强度(σmax)与100%定伸强度(σ100)随着PP-g-MAH用量的增加而增大,在质量分数为6%时,分别为13.4 MPa和9.0 MPa,较未添加PP-g-MAH时分别提高13.6%和76.5%;撕裂强度则下降4.0%。复合材料的毛细管流变实验和淬断面扫描电子显微照片分析表明:PP-g-MAH的加入改善了复合材料中MH、EG与O-SEBS/PP共混物基体间的界面黏合力,提高了相容性。     

Kinetics of thermo-oxidative degradation of zinc borate/microcapsulated red phosphorus with magnesium hydroxide in flame retarded polypropylene composites

The flammability and the thermo-oxidative degradation kinetics of zinc borate (ZB) and microcapsulated red phosphorus (MRP) with magnesium hydroxide (MH) in flame-retardant polypropylene (PP) composites were studied by limiting oxygen index (LOI), TGA, and FTIR spectroscopy. The results show that ZB/MRP is a good synergist for improving the flame retardancy of the PP composites. The Kissinger and Flynn-Wall-Ozawa methods were used to determine the activation energy (E) for degradation of PP composites. The results from the TGA curves indicate that the thermal stability of PP/MH/ZB and PP/MH/ZB/MRP composites is better than that of PP/MH composites. The kinetic results show that the values of E for degradation of PP/MH/ZB/MRP composites is much higher than those of PP/MH and PP/MH/ZB composites. The FTIR spectra data show that the incorporation of MH improves the thermo-oxidative stability of PP, especially for PP/MH composites with suitable content of MRP at higher temperatures. These data indicate that the synergistic flame retardants used in this work have a great effect on the mechanisms of pyrolysis and combustion of PP/MH composites.     

Effects of zinc borate and microcapsulated red phosphorus on mechanical properties and flame retardancy of polypropylene/magnesium hydroxide composites

In this paper, the mechanical properties and flame retardancy of zinc borate (ZB) and microcapsulated red phosphorus (MRP) with modified magnesium hydroxide (MH) in flame-retardant polypropylene (PP) were studied by mechanical properties test, UL-94 test, and thermogravimetric analysis (TGA). The crystallization behaviors of the composites were investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The addition of ZB could improve tensile strength and elongation at break of PP/MH composite. The MRP powders had a little effect on the mechanical properties of the PP composites. DSC results showed the addition of ZB and MRP weakened the heterogeneous nucleation effect of MH on PP. The addition of ZB and MRP had a great effect on the flammability of the PP/MH/EG composites. The thermal stability of PP/MH/ZB and PP/MH/ZB/MRP composites was better than that of PP/MH composite.     

Structure and properties of polypropylene composites filled with magnesium hydroxide

Silane and silicone oil modified superfine magnesium hydroxide (MH) was filled into polypropylene (PP) as a flame retardant. The PP and flame‐retarded PP composites were studied for their mechanical properties and rheological behaviors by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), limiting oxygen index (LOI), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that the addition of MH improved flame retardancy of PP/MH composites, but seriously deteriorated mechanical properties of the composites. Surface treatment of MH could significantly improve tensile and impact strength of PP/MH composite because of its enhanced interfacial adhesion between MH and PP matrix. DSC results showed that MH had heterogeneous nucleation effect on PP. Surface treatment of MH weakened its heterogeneous nucleation effect. POM results showed that the dispersion of MH particles played an important role in the crystalline morphology and spherulite size of PP crystals. TGA indicated that MH greatly enhanced the thermal stability of PP. The introduction of treatment agent further improved the thermal oxidative stability of the composite. According to LOI, silane‐treated MH greatly enhanced flame retardancy of PP/MH composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4943–4951, 2006     

Study on Morphology,Rheology and Mechanical Properties of Thermoplastic Elastomer Polyolefin (TPO)/Carbon Nanotube Nanocomposites with Reference to the Effect of Polypropylene-grafted-Maleic Anhydride (PP-g-MA) as a Compatibilizer

The structure–property relationships of polypropylene/ethylene-propylene-diene (PP/EPDM) (80/20) nanocomposites containing single-walled carbon nanotubes (SWCNTs) by melt-mixing process were investigated, the main focus being on the effect of SWCNTs concentration and compatilizer content. Morphological observations by scanning electron microscopy (SEM) are presented in conjunction with the mechanical, thermal, and rheological properties of these nanocomposites. The tensile modulus of nanocomposites was enhanced by increasing the SWCNTs concentration. A high level of toughness in the thermoplastic elastomer polyolefin (TPO)/SWCNTs nanocomposite was achieved with 0.5 wt% of SWCNTs and 1 wt% of polypropylene-grafted maleic anhydride (PP-g-MA). Differential scanning calorimetry (DSC) experiments confirmed the nucleation effect of nanotubes on the crystallization process of the TPO/SWCNTs composites. An appreciable viscosity upturn and a non-terminal low frequency storage modulus were observed in nanocomposites containing SWCNTs whose values increased in the presence of compatibilizer.     

Biocomposites based on date palm flour reinforced (70/30) polypropylene/thermoplastic starch blend: Effects of flour treatment and selective dispersion

In this work, biocomposites have been prepared from a matrix consisting of polypropylene (PP) and thermoplastic starch (TPS) compatibilized using maleic anhydride (MA) grafted PP (PP-g-MA) and flour obtained from local date palm trees (DPF). To mediate the high hydrophilic character of the filler and attain an optimal dispersion, MA treated DPF (MA-DPF) was prepared via DPF esterification. Pretreated and MA treated DPF composites have been prepared by incorporating 10, 20 and 30% of the flour. MA-DPF has also been dispersed according to a second method consisting of dispersing the flour into starch/glycerol mixture before plasticizing to obtain MA-DPF modified TPS batches that were incorporated into PP to get the same matrix composition and flour loadings as for the first composites. The study of the composites properties proved the MA-DPF efficiency in increasing their impact resilience and diminishing their aptitude to water absorption. This was possible due to the association of the MA-DPF/TPS existing interactions to the better affinity of the esterified flour for the PP phase through its reduced hydrophilic nature. Also, SEM analysis confirmed that the interesting impact and water resistances of MA-DPF modified TPS filled PP composites derive from the DPF reinforced TPS phase consisting the materials.     

Effect of sodium dodecylbenzene sulphonate modifier and PP-g-MA on the morphology and thermal conductivity of PP/EG composites

This study investigates the influence of expanded graphite (EG) and sodium dodecylbenzene sulfonate (SDBS) treated EG (SDBS/EG) on the structure, thermal stability and thermal conductivity of polypropylene (PP) and polypropylene/maleic anhydride-grafted polypropylene (PP/MAPP) blend. The dispersion of EG and SDBS/EG was characterized by scanning electron microscopy (SEM). The SDBS-EG showed a crushed and randomly deformed structure. There was an improved interfacial adhesion between the polymer and the SBDS-EG particles. The graphite dispersed much better with less restacking for PP/MAPP/SDBS/EG system. The better dispersion also contributed towards the improved compatibility between the PP or PP/MAPP and SBDS/EG. The SDBS functionalised EG composites showed better thermal stability than the non-functionalized SDBS composites. It was further shown that the functionalized graphite significantly improved the thermal conductivity of the PP and PP/MAPP. This is because the functionalized SDBS/EG seemed to improve the interfacial heat transfer between the conductive filler (EG) and PP matrix.