Studies on the Effect of Reactive Polypropylene on the Properties of Filled Polyolefin Composites. Part 1. Advantages of Solid-Phase-Grafted Maleated Polypropylene Over Melt-Phase-Modified Polymers

The results summarize the problem associated with grafting of maleic anhydride (MAH) on polypropylene (PP) in the melt phase and also describe a new method for grafting PP with MAH in the solid phase. The effectiveness of the solid phase modified maleated polypropylene (MAH-PP) as interphase modifier has been documented by comparing the properties of calcium carbonate filled polypropylene composites (PP-CaCO₃) treated with solid phase modified MAH-PP with that of the melt phase modified MAH-PP treated composites. The solid-phase modification of PP by MAH is nontoxic and is also free from unreacted MAH. The modifier also improves the tensile strength and impact resistance of unmodified PP-CaCO₃ composites.     

玻璃纤维增强聚丙烯的力学性能研究

研究了玻璃纤维(GF)和马来酸酐接枝聚丙烯(PP-g-MAH)对聚丙烯力学性能的影响。结果表明:随着GF与PP的质量比增加,玻璃纤维增强聚丙烯的拉伸强度增加,冲击强度总体呈下降趋势。当PP与GF的质量比为55∶45时,拉伸强度最高,达到45MPa。当PP与GF的质量比一定时,在玻璃纤维增强聚丙烯复合材料中添加增容剂马来酸酐接枝聚丙烯(PP-g-MAH),可使其拉伸强度得到很大的提高,但是冲击性能却下降。当PP与GF的质量比为75∶25时,随PP-g-MAH与PP/GF复合材料的质量比增加,其拉伸强度先增大后减小,其冲击性能总体呈下降趋势。当PP-g-MAH,PP和GF的质量比为15∶75∶25时,其综合性能最优,拉伸强度为50.5MPa,冲击强度为4.3kJ/m2。     

PP-g-MAH增容膨胀阻燃聚丙烯体系的研究

利用熔融共混制备了聚丙烯/膨胀型阻燃剂/马来酸酐接枝聚丙烯(PP/IFR/PP-g-MAH)阻燃复合材料。通过极限氧指数、热重分析、扫描电子显微镜及力学性能测试研究了PP-g-MAH对阻燃复合材料的阻燃性、热稳定性、微观形貌及力学性能的影响。结果表明,PP-g-MAH作为相容剂,当添加5 %的PP-g-MAH时,复合材料的极限氧指数达到30 %, 垂直燃烧达到UL 94 V-0级;随着PP-g-MAH含量的增加,阻燃剂和基体PP之间的界面作用力提高,体系的拉伸强度和弯曲强度均有提升,冲击强度减小幅度不大;与未加PP-g-MAH的复合材料相比,添加相容剂的复合材料成炭率明显提高。     

Preparation of composites based on recycled polypropylene and automotive shredder residue

In past research, mechanical recycling of automotive shredder residue (ASR) has led to serious deterioration of material performance, and real‐scale application in this way still remains a challenge. Here, we report a sustainable approach called solid‐state shear milling (SSSM) for the production of high‐performance polypropylene (PP)/ASR composites with robust mechanical performance on a commercial scale. After the SSSM process, the obtained 50/50 wt% PP/ASR composite exhibited a 41.3% increase in tensile strength, 32.9% increase in flexural strength and 55.0% increase in impact toughness when compared with corresponding composites made by traditional direct melt blending. In particular, the toughness of the material can be improved by further addition of PP grafted with maleic anhydride with toughness comparable to that of recycled PP, and a 325% increase in toughness can be obtained with addition of styrene–butadiene–styrene block copolymer grafted with maleic anhydride. This PP/ASR composite shows good processability and high thermal stability, and meets the requirements of many applications for nonstructural products. The approach presented in this paper highlights a novel technique for ASR recycling. © 2018 Society of Chemical Industry     

聚丙烯／新型聚烯烃弹性体皮芯型复合纤维的纺靛

对新型聚烯烃弹性体Vistamaxx进行了差示扫描热（DSC）、核磁共振（NMR）分析，结果表明：弹性体Vistamaxxr的软化点较低，熔点与聚丙烯接近，主要由等规丙烯组成，其中含有少量聚乙烯，这些乙烯单元的存在破坏了原有丙烯单元的结晶，使其具有较好的弹性，以Vistamaxxr为芯层、丙烯为皮层，采用熔融纺丝工艺制备出了聚丙烯/Vistamaxxr皮芯复合纤维，确定了最佳熔融纺丝工艺，皮芯复合比为50/50,纺丝温度为230℃,泵供量为12-20g/min,卷绕速度可在800-1000m/min内调节，与聚丙烯纤维相比，此皮芯复合纤维具有更好的韧性.     

Flour rice husk as filler in block copolymer polypropylene: Effect of different coupling agents

Flour rice husk (FRH) was employed as a filler in block copolymer polypropylene (PPB) in order to prepare polymer‐based reinforced composites. Four coupling agents were selected to modify the surface of the rice husk in the composite materials, including two types of functionalized polymers [PP homopolymer grafted with maleic anhydride (MA‐PP) and an elastomer styrene–ethylene–butadiene–styrene triblock copolymer grafted with MA (MA‐SEBS)] and two bifunctional organometallic coupling agents (silane and titanate with linear low‐density polyethylene as a carrier). The influence of each type of coupling agent on the interfacial bonding strength was studied by dynamic mechanical analysis, scanning electronic microscopy, and rheological tests. The results showed that strong interactions were formed between the coupling agents and the filler surface. The addition of a coupling agent with an elastomeric carrier (MA‐SEBS) increased the loss tangent and reduced the storage modulus of the composite. A similar but less intense effect was observed for the titanate coupling agent. However, an antagonistic performance was obtained when MA‐PP and silane were employed as coupling agents. In addition, when the percentage of MA‐SEBS was increased, the impact properties of FRH/PPB blends were improved and the strength was reduced. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1823–1831, 2006     

Influence of interfacial agents on the physicochemical characteristics of binary polyethylene/polyamide 6 and ternary polyethylene/polypropylene/polyamide 6 blends

Binary low-density polythylene/polyamide 6 and ternary low-density polyethylene/polypropylene/polyamide 6 blends were prepared by melt mixing, without and with the addition of two different commercial products [poly(ethylere-co-buthylacrylate-co-maleic anhydride) and poly(ethylene-co-vinylacetate) grafted with maleic anhydride] used as interfacial modifiers. More precisely, the polypropylene was a propylene/ethylene random copolymer, containg 6% by weight of ethylene. The polyamide 6/interfacial agent and polyethylene/ interfacial agent systems were also considered. Differential scanning calorimetry, microscopic observations—together with chemical etchings—and mechanical tests supported the occurrence of strong interactions at the interface, especially when using the buthyl acrylate-based agent. The compatibilizing effect of the interfacial agents was also analyzed in the light of interfacial tension determinations. Eventually, low-density polyethylene modifications induced by compatibilization were studied carrying out WAXD analysis. © 1996 John Wiley & Sons, Inc.     

Basalt fiber reinforced and elastomer toughened polylactide composites: Mechanical properties,rheology, crystallization,and morphology

A series of the reinforced and toughened polylactide (PLA) composites with different content of basalt fibers (BF) were prepared by twin screw extruder. The toughness of BF/PLA composite s was improved further by the addition of polyoxyethylene grafted with maleic anhydride (POE-g-MAH), ethylene–propylene–diene rubber grafted with maleic anhydride (EPDM-g-MAH), and ethylene-acrylate-glycidyl methacrylate copolymer (EAGMA), relatively. The mechanical properties, rheology, crystallization, and morphology of BF/PLA composites were studied. The results showed that basalt fiber had significant reinforcing and toughening effect in comparsion with glass fiber. EAGMA was more effective in toughening BF/PLA composites than POE-g-MAH and EPDM-g-MAH. When the content of EAGMA achieved to 20 wt %, the impact strength of BF/PLA/EAGMA composite increased to 33.7 KJ/m², meanwhile the value was improved by 71.1% compared with pure PLA. According to dynamic rheometer testing, the use of the three kinds of elastomers increased the melt dynamic viscosity. Differential scanning calorimetry analysis showed that POE-g-MAH and EPDM-g-MAH can decrease the cold crystallization temperature (T_cc) to approximately 20°C and dramatically improve crystallinity (χ_c) of BF/PLA composites. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

聚丙烯/新型聚烯烃弹性体皮芯型复合纤维的纺制

对新型聚烯烃弹性体Vistamaxx进行了差示扫描量热(DSC)、核磁共振(NMR)分析,结果表明:弹性体Vistamaxx的软化点较低,熔点与聚丙烯接近,主要由等规聚丙烯组成,其中含有少量聚乙烯,这些乙烯单元的存在破坏了原有丙烯单元的结晶,使其具有较好的弹性。以Vistamaxx为芯层、聚丙烯为皮层,采用熔融纺丝工艺制备出了聚丙烯/Vistamaxx皮芯复合纤维,确定了最佳熔融纺丝工艺:皮芯复合比为50/50,纺丝温度为230℃,泵供量为12~20g/min,卷绕速度可在800~1000m/min内调节。与聚丙烯纤维相比,此皮芯复合纤维具有更好的韧性。     

The Effect of Multiple Compatibilizers on the Impact Properties of Polypropylene/Polystyrene (PP/PS) Blend

Effects of compatibilizers on impact properties of polypropylene/ polystyrene (PP/PS) blends were studied and carried out through melt blending using co- rotating twin-screw extruder. A combination of two compatibilizers, maleic anhydride grafted polypropylene (PP-g-MA) and styrene maleic anhydride (SMA) was applied into PP/PS blends. Results from the Izod impact strengths, SEM observations and contact angle measurements in PP(50)/PS(50) blends indicated a better compatibilization effect with the use of dual compatibilizers. This was most probably due to improved adhesion between phases in PP/PS blend systems. The use of dual compatibilizers in the blend compositions produced higher impact properties in the PP/PS blend systems compared to single compatibilizer system.     

Relationship between interfacial tension and dispersed‐phase particle size in polymer blends. II. PP/PA6

Simple blends with different viscosity ratios of the components as well as compatibilized blends varying both in type and content of the compatibilizers were used to study the relation between the interfacial tension and the dispersed‐phase particle size for PP/PA6 (80/20 wt %) blends in this work. Four compatibilizing systems including poly(ethylene‐co‐methacrylic acid) ionomers, a maleic anhydride‐grafted propylene copolymer, maleic anhydride‐grafted polypropylene, and a maleic anhydride‐grafted styrene ethylene butylene copolymer were used. For blends prepared in an internal mixer, a power‐law relation was found between the capillary number and the torque ratio of the blends' components. This relation was used to estimate the interfacial tension for the compatibilized blends. The relation between the steady‐state torque of the blends as a measure of viscosity and the estimated values of interfacial tension were also investigated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 54–63, 2003     

Effect of various added compatibilizers on the crystalline structure of polypropylene homopolymer/polybutylene terephthalate and polypropylene copolymer/polybutylene terephthalate polymer blends

Blends of semicrystalline isotactic polypropylene homopolymer and polypropylene copolymer with polybutylene terephthalate with different compatibilizers [i.e., styrene acrylonitrile, Surlyn, styrene–ethylene–butadiene styrene (SEBS), block copolymer and SEBS block copolymer grafted with maleic anhydride] were prepared by melt blending. Wide angle‐X‐ray scattering patterns of injection moldings were obtained. The crystallinity index and d‐spacing were calculated with different concentrations of different compatibilizers. X‐ray results in the structural investigation of the compatibilized blends correlated well with the different compatibilizer concentrations. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1190–1193, 2003     

PP–elastomer–filler hybrids. I. Processing,microstructure, and mechanical properties

Three-component systems with a polypropylene (PP) matrix consisting of polar elastomer (ethylene–propylene rubber and styrene–ethylene–butylene–styrene grafted with maleic anhydride) or of polar PP (PP grafted with maleic anhydride) and filler were investigated. Three microstructures of PP–elastomer–filler hybrids were obtained by processing control and elastomer or PP modification with the maleic anhydride: fillers and rubber particles were separated in the PP matrix, rubber particles with filler core were distributed in the PP matrix, and mixed microstructures of the first and second. A study of mechanical properties showed that the elastic modulus increased in the first microstructure and impact strength increased in the second microstructure. Mechanisms for the relationships between microstructure, processing, and mechanical properties are discussed. © 1996 John Wiley & Sons, Inc.     

Rheological and electrical properties of polypropylene composites containing functionalized multi-walled carbon nanotubes and compatibilizers

Multi-walled carbon nanotubes (MWCNTs) were chemically functionalized through acid, amine, and heat treatments. These were used in the manufacture of composites using polypropylene (PP) as matrix and two types of compatibilizers, maleic anhydride grafted polypropylene (MA-g-PP) and maleic anhydride grafted styrene-ethylene/butylene-styrene (MA-g-SEBS). PP/MWCNT composites filled with modified MWCNTs and compatibilizers were prepared by melt compounding with a twin-screw extruder and were evaluated to understand the effect of dispersion and interfacial interaction on the morphological, rheological, and electrical properties of the composite. When heat treated MWCNTs and compatibilizers were added to the composite, three dimensional network structures were generated through nanotube-nanotube and nanotube-matrix interactions resulting in percolation. Electrical conductivity was dramatically increased when the heat treated MWCNTs were added to the composite and was increased further with the addition of MA-g-SEBS compatibilizer.     

聚丙烯/马来酸酐接枝聚丙烯/环氧树脂/玻璃纤维复合材料的制备及其性能研究

通过双螺杆挤出机制备了聚丙烯/马来酸酐接枝聚丙烯/环氧树脂/玻璃纤维（PP/PP-g-MAH/EP/GF）复合材料,并研究了PP-g-MAH含量、EP含量及固化剂对复合材料力学性能的影响。结果表明,PP-g-MAH含量为10份,含有固化剂EP的含量为3份时,复合材料的综合力学性能最佳;与不加EP的复合材料相比,其拉伸强度、弯曲强度、冲击强度分别提高了41 %、47 %、86 %。扫描电子显微镜分析表明,EP的加入明显改善了GF和PP基体的黏结强度。     

Effect of interfacial modification on metal fiber filled polypropylene composites and property balance

Mechanical properties and electrical conductivity of discontinuous stainless steel fiber (SSF) filled polypropylene (PP) composites were considered as candidates for shielding electromagnetic interference (EMI) applications. In order to improve the unsatisfied impact resistance, surface treatments of SSF and modified PP were introduced. By means of a microdroplet pull-out test, polypropylene grafted maleic anhydride copolymer (PP-g-MAH) was found to be able to enhance the poor interfacial adhesion between fiber and matrix. On this basis, PP-g-MAH was used to prepare conventional composites, and the macromechanical measurements showed evidence that PP-g-MAH helped increase both flexural and impact strength of the composites. However, the good affinity of PP-g-MAH for SSF reduced composite conductivity accordingly. Finally, blends of PP and PP-g-MAH proved to be a solution for the problem, i.e., the impact strength was increased significantly while acceptable electrical resistivity was maintained.     

Effects of toughening agents on the behaviors of bamboo plastic composites

Three kinds of reactive toughening agents of bamboo plastic composites are studied in this article. The bio‐fiber keeps high polarity for the hydroxyl groups of the surface, while polypropylene (PP) matrix resin phase is nonpolar. So, the interfacial compatibility between matrix and enhanced phase is poor. The anhydride in maleic anhydride grafted polypropylene can react with the hydroxyls. A large number of hydroxyl groups on the fiber surface are reduced, and the interfacial bond strength is improved. Three reactive toughening agents: glycidyl methacrylate grafted poly(ethylene‐1‐octene), maleic anhydride grafted poly(ethylene‐octene), and poly(ethylene‐butylacrylate‐glycidyl methacrylate) are chosen to improve the impact toughness. The mechanical properties, compatibility, phase structure, water absorption, and thermal properties of PP blends are all investigated. When the content of toughening agents are controlled between 6% and 8%, not only the impact strength is greatly improved but also the other properties of PP are less affected, which makes the composites with comprehensive and practical applications. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Preparation and properties of styrene–ethylene–butylene–styrene block copolymer/clay nanocomposites: I. Effect of clay content and compatibilizer types

BACKGROUND: Polymer/clay (silicate) systems exhibit great promise for industrial applications due to their ability to display synergistically advanced properties with relatively small amounts of clay loads. The effects of various compatibilizers on styrene–ethylene–butylene–styrene block copolymer (SEBS)/clay nanocomposites with various amounts of clay using a melt mixing process are investigated. RESULTS: SEBS/clay nanocomposites were prepared via melt mixing. Two types of maleated compatibilizers, styrene–ethylene–butylene–styrene block copolymer grafted maleic anhydride (SEBS‐g‐MA) and polypropylene grafted maleic anhydride (PP‐g‐MA), were incorporated to improve the dispersion of various amounts of commercial organoclay (denoted as 20A). Experimental samples were analyzed using X‐ray diffraction and transmission electron microscopy. Thermal stability was enhanced through the addition of clay with or without compatibilizers. The dynamic mechanical properties and rheological properties indicated enhanced interaction for the compatibilized nanocomposites. In particular, the PP‐g‐MA compatibilized system conferred higher tensile strength or Young's modulus than the SEBS‐g‐MA compatibilized system, although SEBS‐g‐MA seemed to further expand the interlayer spacing of the clay compared with PP‐g‐MA. CONCLUSION: These unusual results suggest that the matrix properties and compatibilizer types are crucial factors in attaining the best mechanical property performance at a specific clay content. Copyright © 2007 Society of Chemical Industry     

偶联剂对黄麻增强聚丙烯复合材料冲击强度的影响研究

文章采用塑炼机熔融共混的方法制备了黄麻纤维增强聚丙烯复合材料,用马来酸酐接枝聚丙烯作为偶联剂,制备出性能较好的聚丙烯复合材料。通过力学测试研究了复合材料的抗冲击性能。     

Effect of maleic anhydride grafted polypropylene compatibilizer on the morphology and properties of polypropylene/multiwalled carbon nanotube composite

The effect of maleic anhydride grafted polypropylene (MA‐g‐PP) compatibilizer on the mechanical and electrical properties of a polypropylene‐carbon nanotube composite is presented. Commercially available grades of polypropylene homopolymer (PP) and multiwalled CNT (MCNT) were used to prepare composites (PP/MCNT) by melt compounding. The effects of maleic anhydride graft level and loading on material properties were investigated. The addition of MCNT without compatibilizer enhanced the mechanical properties of PP, whereas addition of both grades of MA‐g‐PP alone had a detrimental effect. When MA‐g‐PP was added as a compatiblizer to the PP/MCNT composite, flexural and tensile moduli increased, indicating that enhanced levels of MCNT dispersion within PP had been achieved. Strength of the nanocomposite decreased with the addition of both grades of MA‐g‐PP, possibly due to the deterioration of the mechanical properties of the polymer in the presence of lower molecular weight MA‐g‐PP. Electrical resistivity improved with both grades of MA‐g‐PP, with higher maleic anhydride graft levels having the most significant effect. Scanning electron microscopy analysis confirmed that the optimum state of dispersion was for the nanocomposite prepared with MA‐g‐PP with highest grafting level. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers