PP/POE/滑石粉复合材料的制备及其在汽车内饰件中的应用

通过分析聚丙烯(PP)和乙烯-辛烯共聚物(POE)的流变特性,选用熔体黏度相近的材料作为基体,以滑石粉为填料,制备了PP/POE/滑石粉复合材料.研究了螺杆组合、助剂种类对复合材料性能的影响,并利用扫描电子显微镜观察了POE和滑石粉在复合材料中的分散情况,考察了该复合材料在改善汽车内饰件外观中的应用状况.结果表明,合适...     

AC／MMA接枝天然橡胶包覆滑石粉填充PP的研究

用丙烯基氯／甲基丙烯酸甲酯（AC／MMA）二元接枝天然橡胶包覆处理滑石粉。研究了处理方法,接枝天然橡胶用量以及滑石粉填充量对低韧性PP拉伸强度和制品冲击强度的影响,并与硅烷偶联剂HK－550处理滑石粉进行了比较,结果表明,AC／MMA二元接枝天然橡胶湿法包覆滑石粉效果最好,包覆滑石粉填充PP在拉伸强度保持较高的情况下,冲击强度得到有效的提高,包覆滑石粉有效地降低了由于滑石粉填充量的增加而导致的复3合材料力学性能降低的幅度,SEM的分析表明,AC／MMA二元接枝天然橡胶包覆滑石粉增加了PP基体层的应力屈服,实现了复合材料的脆韧转变。     

Mechanical and water vapor transport properties of polyurethane/superfine down powder composite membranes

To develop a novel microporous polyurethane (PU) membrane that has higher water vapor transmission rate (WVTR) for use in functional application, down powder with different average particle sizes was blended with PU by using the solution casting method. Scanning electron microscope was used to investigate the changes in the porous structures of PU/superfine down powder (SDP) composite membranes. Attenuated total reflectance Fourier transform infrared spectroscopy curves showed that the addition of SDP decreased the hydrogen bonds of PU matrix. On the basis of wide‐angle X‐ray diffraction curves, the small crystallinity of the PU matrix in PU/SDP composite membranes was lower than that of pure PU membrane. The densities of PU/SDP composite membranes decreased with the increase in SDP content. PU/SDP composite membranes showed a large increase in WVTR and a small decrease in mechanical properties compared to pure PU membrane. Moreover, the WVTR and mechanical properties of PU/down powder composite membranes were found absolutely dependent on the average particle size of down powder. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

低气味、低VOC聚丙烯/滑石粉共混物的研究

采用熔融共混法制备聚丙烯(PP)/滑石粉共混物,利用力学性能测试和热脱附-气相/质谱(TDS-GC/MS)分析手段考察了滑石粉、吸附剂和萃取剂对PP/滑石粉共混物力学性能、熔体流动速率、气味和挥发性有机物(VOC)挥发量的影响。实验结果表明,随着滑石粉、吸附剂和萃取剂含量的增加,PP/滑石粉共混物的气味和总挥发性有机物(TVOC)降低;而吸附剂和萃取剂含量对力学性能几乎没有影响,对熔体流动速率略有影响;另外,随着吸附剂含量的增加,PP/滑石粉共混物的吸湿性会增大,当吸附剂质量分数达到5%时,放置480 h后,其吸水量提高2.7倍;在滑石粉质量分数为20%的PP/滑石粉共混物中,当吸附剂和萃取剂质量分数分别为0.5%,1.0%时,共混物的气味强度和舒适度可分别达到2.5级和0级,TVOC挥发量较挤出后的纯PP下降51%。     

Effect of corn‐zein coating on the mechanical properties of polypropylene packaging films

In this study, a novel film structure of corn zein coated on polypropylene (PP) synthetic films for food packaging applications was developed, and the mechanical properties of the resulting coated film, as affected by the coating formulation, were investigated. Composite structures of PP films coated with corn zein were obtained through a simple solvent casting method. Different amounts of corn zein (5 and 15%) were dissolved in 70 and 95% aqueous ethanol solution at 50°C. Solutions of corn zein plasticized with poly(ethylene glycol) and glycerol (GLY) at various levels (20 and 50%) were applied on corona‐discharge‐treated PP. A statistical analysis based on full factorial design was performed to examine the influence of the coating formulation on the final properties of the corn‐zein‐coated PP films. A significant (p < 0.05) improvement in the coated film's mechanical properties was observed compared to those of the uncoated PP. The effect of the plasticization of the coating solutions was also quite significant. In general, GLY provided better improvements in the mechanical properties of the corn‐zein‐coated PP films. The statistical analysis of the results showed that the corn‐zein and plasticizer concentrations and plasticizer type used in the coating formulations were more effective parameters and had significant effects on the mechanical behavior of the coated PP films. In conclusion, corn‐zein coatings could have potential as alternatives to conventional synthetic polymers used in composite multilayer structures for food packaging applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

成核剂对超微细滑石粉／聚丙烯共混物性能的影响

研究了α和β成核剂对滑石粉／聚丙烯共混物力学性能的影响。结果表明：α成核剂可以提高材料的拉伸强度、弯曲强度、弯曲模量和硬度等,冲击强度略有下降,而β成核剂使其韧性明显增强;α和β成核剂的加入皆使复合体系的耐热性显著提高,与β成核剂相比,β成核剂更能提高共混物的热变形温度。     

硫酸钙晶须表面包覆二氧化硅的制备及机理分析

研究了以硅酸钠为硅源,采用液相沉积法在硫酸钙晶须表面包覆致密二氧化硅纳米膜对硫酸钙晶须进行无机改性。通过扫描电镜（SEM）、X射线衍射（XRD）、傅里叶红外光谱仪（FT-IR）等检测手段,对包覆二氧化硅的硫酸钙晶须的形貌及包覆机理进行了分析。结果表明,在反应温度为90 ℃、反应液pH为9条件下,可以得到二氧化硅致密包覆膜,包覆后的硫酸钙晶须可显著提高ζ电位;将该材料应用于三元乙丙橡胶（EPDM）/聚丙烯（PP）热塑性弹性体中,可有效改善晶须在热塑性弹性体中的分散程度。     

PP/Nano-SiO_2包覆长石复合材料的制备、性能及结构表征

采用纳米二氧化硅(nano-SiO2)对长石填料进行表面修饰改性,且对其表面包覆形貌进行了分析和表征。以nano-SiO2包覆改性长石为填料制备了聚丙烯(PP)/包覆长石复合材料,并对其力学性能、热稳定性进行了研究。结果表明:当包覆长石用量为3%时,复合材料的拉伸强度和断裂伸长率均达到最大值;同纯PP相比,该复合材料的热稳定性和韧性有所提高;另外,nano-SiO2包覆长石粉体对PP具有异相成核作用,提高了PP基体的结晶度。     

The effect of the volume fraction of dispersed phase on toughness of injection molded polypropylene blended with SEBS,SEPS, and SEP

The effect of the volume fraction of a dispersed phase on improvement in the toughness of injection‐molded isotactic polypropylene (i‐PP), blended with a styrenic thermoplastic elastomer, has been studied. The volume fraction of the dispersed phase, which indicates compatibility between elastomer and i‐PP, depends on the molecular structure of a soft segment and the copolymerization ratio of styrene. The volume fraction of the dispersed phase of the i‐PP blended with styrene‐ethylene‐propylene‐styrene tri‐block copolymer (SEPS) was higher than that of the i‐PP blended with styrene‐ethylene‐butylene‐styrene tri‐block copolymer (SEBS). The volume fraction of the dispersed phase increases as the copolymerization ratio of styrene increases. Improvement in the toughness of the blended i‐PP clearly depends on relaxation of strain constraint by void formation from the dispersed phase. Its efficiency proved to be dependent on the strength and the volume fraction of the dispersed phase depending on the compatibility between elastomer and i‐PP. POLYM. ENG. SCI., 45:1630–1638, 2005. © 2005 Society of Plastics Engineers     

Enhanced adhesion force based on microphase separation induced by complexation of ferric ions and polyurethane matrix

Waterborne polyurethane elastomer (WPU) has been widely used as a glue, but it still has some drawbacks, including a long cure time and weak adhesive force. In order to overcome these drawbacks, a new composite [PU/ferric ion complexation (Fe/PU)] with high adhesive strength was successfully prepared using ferric ion (Fe³⁺) as a complexing agent. Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and tensile testing were used to characterize the chemical structure and mechanical properties of the as‐obtained composites. Introduction of the ferric ion induces a certain degree of microphase separation, resulting in better mechanical strength and interfacial adhesion. The mechanical properties of the PU composite with ferric ions are higher than that of pure PU. The adhesive strength of the 25%‐Fe/PU composite is 32.46 ± 3.1 MPa, exhibiting superior adhesive strength. The tensile strength was enhanced 34%, and the elongation was enhanced 23.6% compared to pure PU. Furthermore, the Fe/PU composite, coordinated with ferric ions, exhibits an enhanced storage modulus and reduced loss coefficient compared to PU. We can foresee that Fe/PU composites will play an important role in the building and engineering areas. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46069.     

Mode I and Mode II delamination resistance and mechanical properties of woven glass/epoxy–PU IPN composites

The effect of polyurethane on the mechanical properties and Mode I and Mode II interlaminar fracture toughness of glass/epoxy composites were studied. Polyurethanes (PU) synthesized using polyols and toluene diisocyanate were employed as modifier for epoxy resin by forming interpenetrating polymer network. The PU/Epoxy IPN was used as matrix material for GFRP. PU modified epoxy composite laminates having varying PU contents were prepared. The effect of PU content on the mechanical properties like interlaminar fracture toughness (Mode I, G_1c and Mode II, G_IIc), tensile strength, flexural strength, and Izod impact strength were studied. The morphological studies were conducted on the fractured surface of the composite specimen by scanning electron microscopy (SEM). Tensile strength, flexural strength, and impact strength of PU‐modified epoxy composite laminates were found to increase inline with interlaminar fracture toughness (G_1c and G_IIc) with increasing PU content to a certain limit and then it was found to decrease with increase in PU content. It was observed that toughening of epoxy with PU increases the Mode I and Mode II delamination toughness up to 17 and 120% higher than that of untoughened composite specimen, respectively. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Adhesion of propylene–ethylene copolymers to high‐density polyethylene

The adhesion of some propylene–ethylene (P/E) copolymers to polypropylene (PP) and high density polyethylene (HDPE) was studied in order to compare them with other olefin copolymers as compatibilizers for PP/HDPE blends. A one‐dimensional model of the compatibilized blends was fabricated by layer‐multiplying coextrusion. The microlayered tapes consisted of many alternating layers of PP and HDPE with a thin tie‐layer inserted at each interface. The thickness of the tie‐layer varied from 0.1 to 15 μm, which included thicknesses comparable to those of the interfacial layer in a compatibilized blend. In the T‐peel test, the P/E copolymers delaminated at the HDPE interface. An elastomeric P/E with higher ethylene content exhibited substantially higher delamination toughness than a more thermoplastic P/E with lower ethylene content. Inspection of the crack‐tip damage zone revealed that a change from deformation of the entire tie‐layer to formation of a localized yielded zone was responsible. By treating the damage zone as an Irwin plastic zone, it was demonstrated that a critical stress controlled the delamination toughness. The temperature dependence of the delamination toughness was also measured. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Effect of plasma treatment of silk fibroin powder on the properties of silk fibroin powder/polyurethane blend film

In this study, silk fibroin powder was treated by dielectric barrier discharge (DBD) plasma. The objective is to improve the performance of the silk fibroin powder/polyurethane (PU) blend film used in biomechanical field. The scanning electron microscope (SEM) showed that the plasma‐treated powder was broken into small particles and the film from the treated powder became homogeneous and dense. Fourier transform infrared spectroscopy (FTIR) revealed that the hydrophobic groups in silk fibroin powder were oxidized during plasma treatment. Little change in chemical composition was found on the surface of the blend film from plasma‐treated powder. The fracture strain of the blend film from plasma‐treated powder was remarkably raised, whereas its tensile strength was influenced significantly by the plasma treatment conditions. The wet‐out time of the plasma‐treated powder/PU film was shortened considerably. This indicates the improved hydrophilicity of the blend film. In addition, the decreased values of water vapor permeability suggested that the structure of the blend film became dense. This might result from the strong interfacial adhesion between plasma‐treated powder and PU. POLYM. ENG. SCI., 50:1705–1712, 2010. © 2010 Society of Plastics Engineers     

Solar reflectance,surface adhesion,and thermal conductivity of wood/natural rubber composite sheet with Tio2/polyurethane topcoat for roofing applications

Effects of titanium dioxide (TiO₂) dosage in polyurethane (PU) coating and PU coating thickness on solar reflectance, surface adhesion, crack resistance to bending, and thermal conductivity of wood/(natural rubber) (WNR) composite sheet were studied before and after prolonged UV aging. The TiO₂ powder content added to the PU coating was varied from 0 to 15 parts per hundred parts of PU. The average PU coating thickness on the WNR composite sheet was altered from 127 ± 10 to 315 ± 10 μm. The experimental results suggested that the solar reflectance slightly increased with increasing TiO₂ powder but did not change upon varying the PU coating thicknesses. The presence of TiO₂ in the PU coating caused a slight decrease in thermal conductivity because of porosities occurring due to the presence of voids, but increasing the TiO₂ powder content in the coating resulted in a progressive increase in thermal conductivity of the composite sheet. In a UV‐accelerated weathering tester (UVB 313 nm), the lightness of the PU coating slightly increased owing to PU discoloration, whereas the solar reflectance, PU/WNR layer adhesion, and crack resistance to bending remained unaffected with increasing UV aging time. J. VINYL ADDIT. TECHNOL., 18:184–191, 2012. © 2012 Society of Plastics Engineers     

汽车内饰件用聚丙烯材料的研究

以聚丙烯(PP)为基体树脂,(乙烯/辛烯)共聚物(POE)为抗冲改性剂,滑石粉为填料制得了汽车内饰用PP改性料,研究了PP种类及用量、增韧剂用量、滑石粉粒径等对材料性能的影响。结果表明:以PP(K7760)30份,PP(GD320)30份,增韧剂POE(EG8150)18份,填充剂滑石粉(2500目)20份,抗氧剂、偶联剂等助剂2份制得的PP改性料满足汽车内饰件性能的要求。     

Impact toughness,viscoelastic behavior,and morphology of polypropylene–jute–viscose hybrid composites

In this investigation, we studied the impact toughness and viscoelastic behavior of polypropylene (PP)–jute composites. In this study, we used viscose fiber as an impact modifier and maleated PP as a compatibilizer. The toughness of the composites was studied with conventional Charpy and instrumental falling‐weight impact tests. The composites’ viscoelastic properties were studied with dynamic mechanical analysis. The results show that the incorporation of viscose fibers improved the impact strength and toughness to 134 and 65% compared to those of the PP–jute composites. The tan δ peak amplitude also increased with the addition of the impact modifier and indicated a greater degree of molecular mobility. The thermal stability of the composites was evaluated with thermogravimetric analysis. The addition of 2 wt % maleated polypropylene (MAPP) to the impact‐modified composite improved the impact strength and toughness to 144 and 93%, respectively. The fiber–matrix morphology of the fracture surface and the Fourier transform infrared spectra were also studied to ascertain the existence of the type of interfacial bonds. Microstructural analysis showed the retention of viscose fibers in the composites compared to the more separated jute fibers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42981.     

Study on morphological,rheological, and mechanical properties of PP/SEBS‐MA/SGF hybrid composites

Hybrid composite samples composed of polypropylene as matrix, 20% short glass fibers (SGF) as reinforcement and varying amount of maleic anhydride (MA) grafted SEBS as compatibilizer and impact modifier were prepared by melt mixing in a modular twin screw extruder. The SEM examination performed on cryogenically fractured surfaces of hybrid samples showed a three‐phase type morphology in which SGF and rubber phase finely distributed in the PP matrix. SEM results also revealed that in the hybrid samples containing SEBS‐MA, the surface of the SGF are coated with a thin layer of SEBS‐MA, indicating a strong adhesion between SGF and matrix materials. The results of rheological studies showed nearly equal viscosity for compatible and incompatible hybrid samples. Tensile yield strength enhanced with increasing rubber content up to 10% above which it decreased and highest impact strength enhancement was obtained for sample containing 20% rubber. The impact strength of composites was found to be increased with increasing the SGF content. In final, it was shown that a good balance between stiffness and toughness could be achieved by adjusting the SGF and rubber content in this ternary system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2704–2710, 2007     

Development of a new thermoplastic laminate system

In this investigation an all-olefin thermoplastic laminate was developed and characterized. Commingled glass-fiber polypropylene (PP) composite was used as skin and HDPE (PE) foam with closed cells as core. Infra-red heating was used for melting the surfaces of the substrates for surface fusion bonding with a cold press. Two tie-layer films, viz., ethylene-propylene copolymer (EPC) and HDPE/elastomer blend were used as hot-melt adhesives for bonding the substrates. Singlelap shear joints were prepared from PP composite and PE foam adherends with a bonding area of 25.4 mm × 25.4 mm to determine the bond strength. EPC tie-layer adhesive provided higher bond strength (2.68 × 10⁶ N/m²) to the all-olefin laminate than that based on HDPE/elastomer blend (1.93 × 106 N/m²). For EPC tie-layer-based laminates, a mixed mode of failure was observed in the failed lap shear samples: about 40% was cohesive failure through the tie-layer, and the rest of failure was interfacial, either at PP composite or PE foam surfaces. Environmental scanning electron micrographs (ESEM) revealed that in the process of surface fusion bonding, PE foam cells in the vicinity of interphase (800-μm-thick) were coalesced with high temperature and pressure. No macro-level penetration of the tie-layer melt front into the foam cells was observed. As the surface morphology of foam was altered due to IR surface heating and the PP composite bonding side had a resin-rich layer, the bonding situation was closer to that between two polymer film surfaces.     

The influence and mechanism of elastomer types on electrical and mechanical properties of polypropylene insulation materials for high voltage cables

Polypropylene (PP) becomes a superior candidate material for new environmentally friendly cable main insulation with its excellent heat resistance, electrical properties, and degradability. However, in practical application, PP material is aging and vulnerable and its toughness is poor. The mechanical properties of PP material can be improved by elastomer modification, but the effects of different elastomers on the comprehensive properties of composite specimens are quite different. In this paper, the electrical and mechanical properties of different types of elastomer-modified PP composites are compared and analyzed by combining experimental and molecular simulation (MS) methods. The experimental results show that the SEBS/PP composite material has the lowest trap energy levels among all kinds of composite materials, its space charge accumulation is 1.96 × 10⁻⁹C, and the mechanical and rheological properties improvement of the composite is the most remarkable. Meanwhile, the volume resistivity is reduced by two orders of magnitude compared with pure PP. However, the breakdown strength of all kinds of composite materials decreases by different degrees after the modification. The solubility parameters (δ) and the free volume are further investigated by the molecular simulation, which shows that the δ of SEBS is similar to that of PP, which represents the best compatibility. Moreover, the SEBS/PP composite material has the strongest inter-molecular force and the most excellent toughness improvement for PP. This work provides a theoretical basis for elastomer selection in PP modification.     

Influence of third component on mechanical properties and thermal stability of polypropylene/(regenerated polyurethane) blends

The possibility of polypropylene (PP) modification by regenerated polyurethane (PU), obtained after partial thermochemical decomposition of waste PU, has been studied. The degradation product was a thermoplastic mixture, applicable for reuse without any purification and fractionation. It was proved that regenerated PU could be reused as an effective polymeric plasticizer for PP and that the addition of regenerated PU did not decrease the thermal stability of PP. In order to improve further the elongation at break of PP modified by regenerated PU, a third component was added to the PP/(regenerated PU) blend. The influence of the third component on the mechanical properties and thermal stability of the blends was evaluated by using a universal testing machine (UTM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The data showed that the elongations of PP/(regenerated PU) blends with styrene‐ethylene‐butylene‐styrene polymer (SEBS) were obviously better than those of the PP/(regenerated PU) blend without the third component and with PP‐g‐MA or SEBS‐g‐MA (MA = maleic anhydride). In addition, the thermal stability of PP/(regenerated PU) blends with a third component was almost same as that of the PP/(regenerated PU) blend without a third component. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.