正交设计在改性纳米CaCO3/PVC复合体系中的应用

选择不同的方法对纳米CaCO3进行表面改性,研究了表面处理剂对CaCO3/PVC纳米复合材料界面结合强度、力学性能及加工性能的影响。通过正交实验设计得到了力学性能最佳时的制备条件:表面处理剂选用钛酸酯偶联剂,其用量4%(质量分数),纳米CaCO3用量15%(质量分数)。极差分析结果表明,对冲击强度而言,主要影响因素为表面处理剂用量;扫描电镜显示,钛酸酯偶联剂处理可使纳米CaCO3颗粒在PVC基体中达到良好分散,并提高其界面结合强度;流变性能研究表明,经钛酸酯处理的纳米CaCO3填充PVC具有更低的平衡转矩。     

纳米CaCO3对PVC复合材料的研究

笔者研究了基体韧性、纳米CaCO3直接填充PVC对复合材料力学性能的影响，采用钛酸酯处理后的纳米CaCO3对PVC复合材料力学性能的影响，结果表明适当的基体韧性有助于聚氯乙烯复合材料获得较高的冲击强度。     

不同碳酸钙填充聚氯乙烯复合材料力学性能研究

用直接填充分散法(熔融共混法)将微米、亚微米、纳米、纳米包覆微米级复合(微-纳米复合)碳酸钙(CaCO_3)填充到聚氯乙烯(PVC)基体中,制备出不同配比的PVC/CaCO_3复合材料,测量并对比分析了不同复合材料体系的力学性能,计算了复合材料的界面黏结强度。结果表明:多数情况下,PVC/CaCO_3复合材料比纯PVC具有更好的力学性能;改性CaCO_3比未改性CaCO_3填充的PVC复合材料的力学性能更高;纳米包覆重质CaCO_3比普通重质CaCO_3填充的PVC复合材料的力学性能更好;在四种CaCO_3样品中,普通轻质CaCO_3和超细轻质CaCO_3填充PVC复合体系的力学性能相对较好;就界面黏结强度而言,超细轻质CaCO_3与基体树脂的界面黏结强度最高,普通轻质CaCO_3的最低,纳米包覆CaCO_3(通过化学方法在重质CaCO_3表面生成纳米级CaCO_3)与PVC基体树脂的界面黏结强度比重质CaCO_3的高,改性后的CaCO_3与基体的界面黏结强度均有所提高。     

CPE对纳米CaCO3增韧PVC复合材料界面和性能的影响

研究了CaCO3/CPE(氯化聚乙烯)/PVC(聚氯乙烯)纳米复合材料的结构和性能,探讨了CPE对纳米CaCO3/PVC复合材料界面作用和力学性能的影响. SEM结果显示,引入CPE可明显改善纳米CaCO3颗粒在PVC基体中的分散性和相容性,提高其界面作用. 引入界面作用参数定量表征纳米CaCO3颗粒与基体之间的界面结合作用,证实随着CPE加入量的增大,基体和颗粒之间的界面作用逐渐增大. 力学性能研究表明,相对于仅用纳米CaCO3增韧PVC,在CPE加入量为PVC的0~8%(w)范围内,用CPE和纳米CaCO3协同增韧可以更好地提高复合材料的冲击强度. 复合材料的冲击强度在CaCO3/CPE/PVC质量比为25/8/100时达到纯PVC的5.6倍,是纳米CaCO3/PVC(25/100)体系的2倍.     

纳米二氧化硅颗粒表面设计及其填充聚氯乙烯复合材料的性能

利用表面原位接枝聚合在纳米二氧化硅颗粒表面引入聚甲基丙烯酸甲酯(PMMA)高分子链段,用共混法制备了nano-SiO2/PVC复合材料,研究了不同界面特性时SiO2/PVC复合材料的力学性能.研究结果表明通过表面原位接枝聚合反应可以在纳米二氧化硅颗粒表面接枝聚甲基丙烯酸甲酯;表面接枝PMMA的nano-SiO2/PVC复合材料在力学和加工性能等方面都优于偶联剂处理和表面未处理样品.在纳米二氧化硅颗粒填充量为0%～8%(wt)时,复合材料的拉伸强度和冲击强度随着填充量的提高先上升后下降,并在4%～6%(wt)达到最大值.经PMMA表面接枝后SiO2/PVC具有更强的界面作用,偶联剂KH570处理的次之,表面未处理样品的最差.     

改性微晶白云母/PVC复合材料的制备及性能研究

以微晶白云母为原料,以钛酸酯偶联剂NDZ-101为改性剂,对微晶白云母进行改性研究,并将表面改性后的微晶白云母加入聚氯乙烯(PVC)材料中制得微晶白云母/PVC复合材料.测试了改性粉体与石蜡体系的黏度及复合材料的力学性能,并采用扫描电子显微镜测试研究了其微观结构.结果表明,钛酸酯偶联剂NDZ-101能有效改善微晶白云母表面与有机物质的界面结合,并且将经钛酸酯偶联剂NDZ-101改性的微晶白云母加入PVC基体中能提高微晶白云母/PVC复合材料的力学性能,当钛酸酯偶联剂的用量为0.7%、微晶自云母用量为10%时,微晶白云母/PVC复合材料的力学性能最好.     

改性纳米CaCO3/PVC复合材料的力学性能

采用钛酸酯偶联剂和PMMA接枝方法改性纳米碳酸钙,并采用熔融共混法制备了改性纳米CaCO3增韧PVC（CaCO3／PVC）复合材料,研究了复合材料的力学性能。对比于未处理纳米CaCO,和钛酸酯偶联剂处理纳米CaCO3,PMMA接枝聚合改性纳米CaCO3与基体的相容性最好,增韧PVC复合材料的拉伸强度得到较大幅度提高。     

偶联剂与甘蔗渣／PVC复合材料性能的研究

分别用硅烷偶联剂KH560和钛酸酯偶联剂NDZ311对甘蔗渣/PVC复合体系进行处理。研究了两种处理方法对甘蔗渣/PVC复合材料力学性能、界面形态、耐水性能和加工性能的影响。结果表明,与未处理的相比,两种处理方法都改善了甘蔗渣和PVC之间的界面相容性,界面黏结得到增强,使复合材料的强度和韧性有了较大的提高,同时改善了甘蔗渣/PVC复合材料的加工性能。钛酸酯偶联剂处理对甘蔗渣/PVC复合材料性能的影响更为显著,当其用量为1%时,复合材料的拉伸强度和冲击韧性均得到提高,其中拉伸强度提高了55%。     

纳米CaCO_3的接枝改性及其填充PVC复合材料的性能

采用表面原位接枝聚合在纳米CaCO3颗粒表面引入聚甲基丙烯酸甲酯(PMMA)或聚丙烯酸丁酯(PBA),用共混法制备了纳米CaC03/PVC复合材料,研究了不同界面特性时纳米CaCO,/PVC复合材料的力学性能.研究结果表明:通过表面原位接枝聚合反应可以在纳米CaCO3颗粒表面接枝PMMA和PBA;表面接枝聚合改性大大促进了纳米CaCO3粒子在PVC基体中的分散行为,增加了复合材料的拉伸强度以及与聚合物的界面粘接强度,但复合材料的冲击强度有所下降.     

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。     

Effect of surface modifiers and surface modification methods on properties of acrylonitrile–butadiene–styrene/poly(methyl methacrylate)/nano‐calcium carbonate composites

Nano‐calcium carbonate (nano‐CaCO₃) was used in this article to fill acrylonitrile–butadiene–styrene (ABS)/poly(methyl methacrylate) (PMMA), which is often used in rapid heat cycle molding process (RHCM). To achieve better adhesion between nano‐CaCO₃ and ABS/PMMA, nano‐CaCO₃ particles were modified by using titanate coupling agent, aluminum–titanium compound coupling agent, and stearic acid. Dry and solution methods were both utilized in the surface modification process. ABS/PMMA/nano‐CaCO₃ composites were prepared in a corotating twin screw extruder. Influence of surface modifiers and surface modification methods on mechanical and flow properties of composites was analyzed. The results showed that collaborative use of aluminum–titanium compound coupling agent and stearic acid for nano‐CaCO₃ surface modification is optimal in ABS/PMMA/nano‐CaCO₃ composites. Coupling agent can increase the melt flow index (MFI) and tensile yield strength of ABS/PMMA/nano‐CaCO₃ composites. The Izod impact strength of composites increases with the addition of titanate coupling agent up to 1 wt %, thereafter the Izod impact strength shows a decrease. The interfacial adhesion between nano‐CaCO₃ and ABS/PMMA is stronger by using solution method. But the dispersion uniformity of nano‐CaCO₃ modified by solution method is worse. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Interfacial structures and mechanical properties of PVC composites reinforced by CaCO3 with different particle sizes and surface treatments

The effects of particle size and surface treatment of CaCO₃ particles on the microstructure and mechanical properties of poly(vinyl chloride) (PVC) composites filled with CaCO₃ particles via a melt blending method were studied by SEM, an AG‐2000 universal material testing machine and an XJU‐2.75 Izod impact strength machine. The tensile and impact strengths of CaCO₃/PVC greatly increased with decreasing CaCO₃ particle size, which was attributed to increased interfacial contact area and enhanced interfacial adhesion between CaCO₃ particles and PVC matrix. Titanate‐treated nano‐CaCO₃/PVC composites had superior tensile and impact strengths to untreated or sodium‐stearate‐treated CaCO₃/PVC composites. The impact strength of titanate‐treated nano‐CaCO₃/PVC composites was 26.3 ± 1.1 kJ m⁻², more than three times that of pure PVC materials. The interfacial adhesion between CaCO₃ particles and PVC matrix was characterized by the interfacial interaction parameter B and the debonding angle θ, both of which were calculated from the tensile strength of CaCO₃/PVC composites. Copyright © 2005 Society of Chemical Industry     

Interfacial interactions in calcium carbonate–polypropylene composites. 2: Effect of compounding on the dispersion and the impact properties of surface-modified composites

This study was carried out to investigate the influences of compounding process and surface treatment on calcium carbonate (CaCO₃) filled polypropylene. The compounding process is discussed with reference to a twin-screw extruder and an internal mixer. The calcium carbonate filler was surface-treated with a liquid titanate coupling agent (LICA 12) and stearic acid. Composites of different weight fractions were prepared by both compounding processes, and their impact properties were evaluated. The notched Izod impact strength increased with CaCO₃ content up to a maximum at about 10 vol%, and then decreased. Surface treatment of CaCO₃ filler generally yielded composites of higher impact strength than untreated system. Though LICA 12 was more effective than stearic acid in modifying the filler, the low-cost stearic acid proved to be more effective when dealing with the impact properties of composites. Moreover, the composites from a Brabender Plasti-corder exhibited better gross uniformity than that from the twin-screw extruder. However, good filler dispersion and uniform microscopic morphology, as revealed by SEM microscopy, was observed in the samples from the twin-screw extruder. Polym. Compos. 25:451–460, 2004. © 2004 Society of Plastics Engineers.     

Nanocomposites of poly(vinyl chloride) and nanometric calcium carbonate particles: Effects of chlorinated polyethylene on mechanical properties,morphology, and rheology

Nanocomposites of poly(vinyl chloride) (PVC) and nano‐calcium carbonate (CaCO₃) particles were prepared via melt blending, and chlorinated polyethylene (CPE) as an interfacial modifier was also introduced into the nanocomposites through preparing CPE/nano‐CaCO₃ master batch. The mechanical properties, morphology, and rheology were studied. A moderate toughening effect was observed for PVC/nano‐CaCO₃ binary nanocomposites. The elongation at break and Young's modulus also increased with increasing the nano‐CaCO₃ concentration. Transmission electron microscopy (TEM) study demonstrated that the nano‐CaCO₃ particles were dispersed in a PVC matrix uniformly, and a few nanoparticles agglomeration was found. The toughening effect of the nano‐CaCO₃ particles on PVC could be attributed to the cavitation of the matrix, which consumed tremendous fracture energy. The notched Izod impact strength achieved a significant improvement by incorporating CPE into the nanocomposites, and obtained the high value of 745 J/m. Morphology investigation indicated that the nano‐CaCO₃ particles in the PVC matrix was encapsulated with a CPE layer through preparing the CPE/nano‐CaCO₃ master batch. The evaluation of rheological properties revealed that the introduction of nano‐CaCO₃ particles into PVC resulted in a remarkable increase in the melt viscosity. However, the viscosity decreased with addition of CPE, especially at high shear rates; thus, the processability of the ternary nanocomposites was improved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2714–2723, 2004     

Influence of aspect ratio of fillers on the properties of acrylonitrile butadiene styrene composites

Aspect ratio (shape) of the filler is one of the key factors which play a vital role in determining the properties of the composites. Fillers like talc and calcium carbonate (CaCO₃) have different aspect ratios and affect the properties differently. This study was carried out to investigate the effect of aspect ratio of the filler on the properties of the acrylonitrile butadiene styrene (ABS) polymer. The rheological, mechanical, thermal properties, and fracture morphology were studied for the ABS composites filled with talc and CaCO₃ at various filler loading. Coupling agent was added to improve the interfacial adhesion between the filler and the ABS matrix. The aspect ratio of fillers affected the flow behavior at lower shear rate, and was insignificant at higher shear rates. The flow‐induced morphology was more effective in case of talc giving a significant increase in the bending modulus. Tensile and flexural strength showed a slight decrease in the values with talc showing better performance as compared to CaCO₃. The reverse was observed in case of impact strength, with CaCO₃ showing lower drop in the values. Aspect ratio of filler had no significant effect on the thermal properties of the composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46023.     

Effect of interfacial interaction on the crystallization and mechanical properties of PP/nano‐CaCO3 composites modified by compatibilizers

To investigate the effect of interfacial interaction on the crystallization and mechanical properties of polypropylene (PP)/nano‐CaCO₃ composites, three kinds of compatibilizers [PP grafted with maleic anhydride (PP‐g‐MA), ethylene–octene copolymer grafted with MA (POE‐g‐MA), and ethylene–vinyl acetate copolymer grafted with MA (EVA‐g‐MA)] with the same polar groups (MA) but different backbones were used as compatibilizers to obtain various interfacial interactions among nano‐CaCO₃, compatibilizer, and PP. The results indicated that compatibilizers encapsulated nano‐CaCO₃ particles, forming a core–shell structure, and two interfaces were obtained in the compatibilized composites: interface between PP and compatibilizer and interface between compatibilizer and nano‐CaCO₃ particles. The crystallization and mechanical properties of PP/nano‐CaCO₃ composites were dependent on the interfacial interactions of these two interfaces, especially the interfacial interaction between PP and compatibilizer. The good compatibility between PP chain in PP‐g‐MA and PP matrix improved the dispersion of nano‐CaCO₃ particles, favored the nucleation effect of nano‐CaCO₃, increased the tensile strength and modulus, but reduced the ductility and impact strength of composites. The partial compatibility between POE in POE‐g‐MA and PP matrix had little effect on crystallization and mechanical properties of PP/nano‐CaCO₃ composites. The poor compatibility between EVA in EVA‐g‐MA and PP matrix retarded the nucleation effect of nano‐CaCO₃, and reduced the tensile strength, modulus, and impact strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Phase structure and mechanical properties of PP/EPR/CaCO3 nanocomposites: Effect of particle's size and treatment

Calcium carbonate (CaCO₃) reinforced polypropylene/ethylene propylene rubber (PP/EPR) copolymer composites for automotive use were developed by means of extrusion and injection molding process. Three kinds of CaCO₃ (stearic acid treated and untreated) nanoparticles and microparticles were used as fillers. The influence of stearic acid, particle size, and filler content on the state distribution and morphology were investigated by SEM and rheological measurements. Two different morphologies were observed: EPR and CaCO₃ dispersed in the PP matrix and a core shell structure, depending on the interactions between EPR and CaCO₃. Toughening mechanisms and mechanical properties of the different systems were investigated. Significant improvement in tensile modulus is observed in all composites, depending on filler content. Elongation and notched impact strength were drastically decreased, especially for composites with nano CaCO₃. Better impact properties were obtained with low content of treated particles, showing the importance of filler treatment. POLYM. ENG. SCI., 55:2859–2868, 2015. © 2015 Society of Plastics Engineers