The properties of polyolefins modified with PET powder

The polyolefin and poly(ethylene terephthalate) (PET) products are the mostly current communal waste materials. The waste polymeric materials are generally difficult to separate, and therefore a processing of nonseparated materials presents an interesting alternative suggestion. The aim of our work was to analyze the possibility of reprocessing of polyolefins by a relative low temperature, and to study the effect of addition of PET solid powder on processing and application properties. The results of our investigations allow to conclude that the solid PET powder may play a role of a heterogeneous nucleator, acting as an α‐phase promoter of an isotactic polypropylene. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

对焦化汽油携带“焦粉”的分析

对延迟焦化装置生产的焦化汽油中所携带"焦粉"的成分及其原因进行了分析。通过热重分析及X射线粉末衍射方法对"焦粉"进行定性分析,经理论计算与实际结果进行对比发现"焦粉"的主要成分为铁的硫化物;而铁的硫化物的产生主要是因为分馏塔塔顶油气中含有大量H2S,在分离油气过程中H2S对管线和器壁的腐蚀所造成的,所谓的焦化汽油携带"焦粉"其实为铁的硫化物。     

基于PE/EPDM胶粉的共混性能研究

通过密炼共混法成功制备了聚乙烯（PE）/废旧三元乙丙橡胶（EPDM）胶粉的热塑性弹性体,研究了不同PE/EPDM共混比和不同相容剂对热塑性弹性体力学性能的影响。实验结果表明：随PE用量增加,拉伸强度、100%定伸应力、硬度提高,拉断伸长率降低。在PE用量不变的条件下,加入相容剂可改善PE/废旧EPDM胶粉热塑性弹性体的基本力学性能,其中随着相容剂氯化聚乙烯（CPE）与马来酸酐接枝苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物（SEBS-g-MA）用量的增加,拉伸强度、100%定伸应力、拉断伸长率和硬度提高;而以马来酸酐接枝乙丙橡胶（EPDM-g-MA）为相容剂时,除拉断伸长率外,拉伸强度、100%定伸应力与硬度则呈现相反的趋势,其随EPDM-g-MA用量增多而降低。     

Thermal and mechanical behavior of unsaturated polyesters filled with phase change material

Samples of commercial unsaturated polyester (UPE) resin, filled with phase‐changeable fillers (PCMs), were prepared, and the thermal and mechanical properties of the cured samples were examined. Fillers chosen were paraffin and Wood's metal. Samples were prepared by making dispersions of these fillers in liquid unsaturated polyester followed by curing with methyl ethyl ketone peroxide (MEKP) and conaphtanate and rigid thermoset samples filled with PCM particles were obtained. The thermal and mechanical behaviors of such a filled composite around the melting points of fillers are very interesting. Effects of varying proportions of PCM on mechanical and thermal properties of final products were examined. The samples show thermal melting behavior without undergoing a change in physical state. Decreases in the maximum working temperature from 75 to 53°C for metal‐filled samples and from 75 to 43°C for paraffin‐filled samples were observed by using dynamic mechanical thermal analysis. Differential scanning calorimetry indicated that heat absorption of paraffin samples were higher than that of metal‐filled samples. For paraffin‐filled samples, heats of fusion were 3.44 cal/g for 10% filled sample and 6.35 cal/g for 20% filled sample. For Wood's metal‐filled samples, heats of fusion were 1.18 cal/g for 10% metal‐filled sample and 1.54 cal/g for 20% metal‐filled sample. Surface hardness was tested with Shormeter D. Surface hardness of metal‐filled composites varied from 86 to 34 shore D at 21°C and 80.6 to 35 shore D at 80°C. For paraffin‐filled samples, surface hardness changed from 86 to 42 shore D at 21°C and from 80.6 to 13 shore D. Morphology of the samples was determined by scanning electron microscopy, of the crack surfaces. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 832–838, 2006     

The physical and mechanical properties of polymer composites filled with Fe‐powder

In this study, the effect of Fe powder on the physical and mechanical properties of high density polyethylene (HDPE) was investigated experimentally. HDPE and HDPE containing 5, 10, and 15 vol % Fe metal–polymer composites were prepared with a twin screw extruder and injection molding. After this, fracture surface, the modulus of elasticity, yield and tensile strength, % elongation, Izod impact strength (notched), hardness (Shore D), Vicat softening point, heat deflection temperature (HDT), melt flow index (MFI), and melting temperature (T_m) were determined, for each sample. When the physical and mechanical properties of the composites were compared with the results of unfilled HDPE, it was found that the yield and tensile strength, % elongation, and Izod impact strength of HDPE decreased with the vol % of Fe. As compared with the tensile strength and % elongation of unfilled HDPE, tensile strength and % elongation of 15 vol % Fe filled HDPE were lower, about 17.40% and 94.75% respectively. On the other hand, addition of Fe into HDPE increased the modulus of elasticity, hardness, Vicat softening, MFI, and HDT values, such that 15 vol % Fe increased the modulus of elasticity to about 48%. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Possible use of ultra‐fine acrylonitrile butadiene rubber powder as filler in natural rubber vulcanizates

Possible use of ultra‐fine acrylonitrile butadiene rubber powder (UFNBRP) as a filler for natural rubber (NR) was investigated. The UFNBRP was added into NR at various concentrations, and the compound properties were determined. It is found that, with increasing UFNBRP loading, the compound viscosity is increased, whereas both scorch time and optimum curing time are significantly reduced. The results also reveal that UFNBRP has negative effect not only on crosslink density but also on most mechanical properties of the vulcanizate, such as tensile strength, tear strength, compression set, and abrasion resistance. The deterioration of these mechanical properties is thought to arise mainly from the combined effect of large phase size of the dispersed UFNBRP and low interfacial adhesion taking place from the polarity difference between UFNBRP and NR. Interestingly, it is found that, after aging, UFNBRP could promote postcuring phenomenon leading to increases of both relative 100% modulus and relative tensile strength. Oil resistance is also found to improve considerably with increasing UFNBRP loading. This improvement is mainly attributed to the dilution effect, i.e., the higher the UFNBRP loading, the lower the NR portion and, thus, the greater the oil resistance of the vulcanizate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of difunctional acids on the physicochemical,thermal, and mechanical properties of polyester polyol‐based polyurethane coatings

Polyester polyol (PP)‐based polyurethanes (PUs) consisting of two difunctional acids [1,4‐cyclohexanedicarboxylic acid (CHDA) and 1,6‐adipic acid (AA)] and also two diols [1,4‐cyclohexanedimethanol (CHDM) and 1,6‐hexanediol (HDO)] were synthesized by a two‐step procedure with a variable feed ratio of CHDA to AA but fixed ratio of CHDM and HDO. The prepared PPs and/or PUs were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy, and atomic force microscopy. The effects of difunctional acids on the thermal, mechanical, and dynamic mechanical thermal properties of PPs or PU films were investigated by thermogravimetry analysis, differential thermogravimetry and dynamic mechanical thermal analysis. The results show that PP exhibits a lowest viscosity with the mole fraction of CHDA and AA at 3 : 7 whereas it delivers a lowest melting point with the mole fraction at 9 : 1. After PPs being cross‐linked by isocyanate trimers, the impact resistance, shear strength and glass transition temperature increase the mixed‐acid formulations with increasing the content of CHDA. In detail, the resultant PU almost simultaneously exhibits the best mechanical and thermal properties when the mole fraction of CHDA and AA is kept constant at 9 : 1, thus giving rise to a high glass transition temperature of 56.4°C and a onset decomposition temperature of 350°C, and also delivering a balanced toughness and hardness with an impact resistance of 100 J/g and storage modulus as high as 10⁹ Pa. This path for synthesis of PP‐based PU provides a design tool for high performance polymer coatings. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41246.     

Mechanical Properties of Polymers Filled with Iron Powder

Mechanical properties of metal-polymer matrix composites were investigated experimentally. High density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS) were used as the polymer matrix and Fe powder in 5, 10, and 15 vol% was used as the metal. The modulus of elasticity, yield and tensile strength, % elongation, Izod notched impact strength, Shore D hardness, and fracture surfaces of the composites were determined. It was found that vol% Fe reduced the Izod impact strength of HDPE much more than that of PP and PS, while Fe powder increased the hardness of HDPE more than that of PP and PS. Among the composites, PS-Fe composites had higher yield, tensile strength and modulus of elasticity than HDPE-Fe and PP-Fe composites. However, % elongation of PS-Fe composites was lower than that of the other composites. In addition, HDPE- and PP-based composites exhibited ductile type fracture, while PS-Fe composites exhibited brittle type fracture.     

Electrical and thermal studies of the distribution of carbon black in a polyester matrix in the presence of aluminum oxide

The distribution of a filler in a polymeric matrix is one of the most important factors affecting the physical properties of the final product. For this reason, the main objective of this study was to introduce aluminum oxide (Al₂O₃), acting as a dispersing agent, to reduce the filler–filler interaction and enhance the filler–polymer interaction. To achieve this aim, the electrical behavior of a styrenated polyester resin filled with different amounts of high‐abrasion furnace black in the presence of 5% Al₂O₃ was studied in the vicinity of the percolation threshold to evaluate the effect of the addition of Al₂O₃ in an attempt to reduce the filler–filler interaction through the polyester matrix. At a certain concentration of carbon black, an abrupt increase was noticed through electrical conductivity, permittivity, and dielectric loss investigations. With this increase, the tendency of conductive chain formation increased through the aggregation of a carbon black particle network. The addition of 5% Al₂O₃ improved the filler distribution by lowering the aggregate size and consequently enhanced the formation of the network. From the Arrhenius temperature dependence of the electrical conductivity, the activation energy and pre‐exponential factor were obtained, and they confirmed the validity of the compensation law for the semiconducting composite systems. The composites were also analyzed by thermogravimetric analysis. Al₂O₃ improved the thermal stability of the composites in comparison with that of a sample free of Al₂O₃. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

PB橡胶粒径对CPVC/PVC/ABS共混体系结构与性能的影响

采用乳液聚合技术合成了一系列不同PB橡胶粒径的ABS核壳改性剂,将其与CPVC、PVC共混,考察了CPVC/PVC/ABS共混物的结构与性能。动态力学分析表明：CPVC与PVC比例为90/10时,CPVC/PVC共混物部分相容,CPVC/PVC/ABS共混物也是部分相容;扫描电子显微镜分析其形态结构表明：共混物中ABS分散受PB橡胶粒径影响,PB橡胶粒径为113 nm的ABS在CPVC中分散最均匀。力学性能测试表明：随着PB橡胶粒径的增加,共混物的冲击强度先增大后减小,拉伸强度并无明显变化。     

Methods for studying the mechanical and tribological properties of hard and soft coatings with a nano-indenter

This study illustrates the capabilities of a nanoindentation/nanoscratch tester to assess mechanical and tribological properties of coating films. Properties such as hardness, elastic modulus, mar and scratch resistance, and critical force for cracking can be accurately measured. Operation of the Nano-Indenter is described in detail. A scanning probe microscope (SPM) is shown to be a valuable supplement to the Nano-Indenter. Well-characterized thermoset acrylic clearcoats and thermoplastic latex films were studied. For the first time, operating parameters are described for measurement of relatively soft coatings, such as films cast from a latex with a glass transition temperature (T_g) of 8°C. Thus, the method is made available for study of most types of coatings. The method can easily discriminate between coatings with different T_gs and crosslink densities. Once operating parameters are established, it takes about 10 minutes for an indentation test and 10 minutes for a scratch test with the Nano-Indenter, and with further automation this time could be reduced. Each indentation test accurately measures hardness and elastic modulus as a function of depth within the coating, and each scratch test provides additional insight into the material’s behavior. The method is sensitive to small changes in polymer composition and formulation, and results are highly reproducible. Presented at the 81st Annual Meeting of the Federation of Societies for Coatings Technology, November 12–14, 2003, in Philadelphia, PA.     

Formation and characteristics of Al−Zn hydrotalcite coatings on galvanized steel

In this study, a process for depositing hydrotalcite (HT) coatings on galvanized steel was developed and the resulting coatings were characterized. Results showed that coatings formed spontaneously on galvanized surfaces upon exposure to ambient temperature alkaline aluminate solutions. Anodic polarization and electrochemical impedance spectroscopy experiments showed clear evidence of surface passivation. Scanning electron microscopy showed the formation of a continuous and conformal surface film comprised on a compact mass of crystallites. X-ray diffraction confirmed that the coating contained an Al−Zn hydrotalcite compound. Coating formation was enhanced by oxidizer and ammonium salt additions. Coatings formed by using best practices were deposited in less than 10 minutes and demonstrated good surface coverage and good organic coating adhesion. HT coatings formed by using best practices showed excellent organic coating adhesion compared to zinc phosphate control coatings. In salt spray testing, the presence of a hydrotalcite conversion coating under an epoxy neat resin was found to delay the onset of red rusting compared to control samples that were epoxy coated, but not conversion coated.     

Structure and Mechanical Properties of Nanocomposites Based on an Amorphous Copolyester

Nanocomposites based on an amorphous copolyester (PCTG) were obtained by melt mixing, changing the screw speed and the nature of the surfactant, which differed in polarity and molecular volume. Using Young's modulus as a measure of the dispersion level, a less‐polar nature and a higher molecular volume of the surfactant appeared as positive structural factors for dispersion of the clay in the less‐polar PCTG. The Cloisite 20A, which led to the highest modulus (widest dispersion), was mixed at different contents with PCTG at the observed optimum screw speed (200 rpm). Intercalated structures were observed by WAXD and TEM. The dispersion was wide, as observed by TEM, and led to a large (77%) modulus increase after 7% organoclay addition and to important increases in both tensile yield stress and dimensional stability in creep.

     

钢渣粉掺量对混凝土力学性能及耐久性能影响研究

为探讨不同钢渣粉掺量对混凝土力学性能及耐久性能的影响,通过将钢渣粉等量替代10％、20％、30％的水泥制备成3组不同钢渣粉的混凝土试块,并分别对其进行抗压强度、抗折强度、加速碳化、抗冻性、水化热等试验,得出以下结论:1)随着钢渣粉掺量的增大,混凝土拌合料的坍落度逐渐增大;2)随着钢渣粉掺量的增大,混凝土的抗压强度、抗折...     

Use of pyrolysed oil shale as filler in poly(ethylene‐co‐vinyl alcohol)

The pyrolysed oil shale (POS) obtained from the pyrolysis of bituminous rock was used as filler in poly(ethylene‐co‐vinyl alcohol) (EVAL). The effects of vinyl alcohol content in the EVAL and the particle size of pyrolysed oil shale in the mechanical properties were investigated. The EVAL was prepared by hydrolysis of poly(ethylene‐co‐vinyl acetate) (EVA) with 8 and 18 wt % of vinyl alcohol content. The composites were prepared in a rotor mixer at 180°C with concentration of pyrolysed oil shale up to 5 wt %. Stress–strain plots of compression‐molded composites showed a synergic behavior in the mechanical properties for low concentrations (1–5 wt %) of POS in all particle sizes and EVAL used. Such behavior indicates a close packing and strong interactions between the inorganic filler and the polymer. Increasing of the vinyl alcohol content of EVAL improved the compatibility between the polymer and filler, but decreasing the POS particle size had no effect on the properties. The modulus and the ultimate tensile strength also increased in all concentrations of POS for both EVAL. Mechanical properties and dynamic mechanical analysis also demonstrated the compatibility between EVAL and POS. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1658–1665, 2004     

Preparation and characteristics of polyacrylic ester‐based water‐free powder coatings in supercritical carbon dioxide

Powder coating for dry coating technique of paper as the promising method has attracted more and more attentions in recent years due to its advantages in reducing the dosage of water and saving energy compared with conventional coating. This study focused on the in situ polymerization of methyl methacrylate (PMMA) under a water‐free condition in supercritical carbon dioxide in the presence of inorganic kaolin. The effects of varying the concentrations of the monomer, initiator, and stabilizer on the molecular weight and morphology of the resultant PMMA were investigated and discussed. Then the powder coating was systematically evaluated and characterized by gel permeation chromatography, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Meanwhile, the feasibility of manufacturing PMMA/kaolin powder coatings was explored, and the mechanism of polymerization and the thermal degradation kinetics of powder coating were studied. The experimental results showed that the properties of PMMA as a film former were suitable with the molecular weight and narrow molecular weight distribution close to that in conventional coating when the concentration of monomer was about 10 wt %, concentration of initiator ～1–1.5 wt % and stabilizer about 10 wt % with respect to monomer. Moreover, the interfacial bonds and dispersion situation of polyacrylic ester‐based water‐free powder coating particles were fairly well, the powder coating possesses good film‐forming property combined with outstanding thermal‐stability performance. The combination of these characteristics makes PMMA/kaolin powder coating an excellent candidate for dry coating technique of paper applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42439.     

Properties of polypropylene filled with chemically treated rice husk

Finely ground rice husk was used as a filler in two commercial grades of polypropylene (PP) in different amounts. Rice husk powder was chemically treated with dilute hydrochloric acid, dilute sodium hydroxide solution, and dimethyl sulfoxide. The mechanical, thermal, and rheological properties of PP filled with untreated and treated rice husk powder were determined. Effectiveness of PP grafted with acrylic acid, PP‐g‐AA, as a compatibilizer was examined. Rice husk powder treated with acid showed significant improvement in the flexural modulus of PP and also less water absorption. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

无机超细粉在丁苯橡胶中的应用

为探讨无机超细粉在橡胶工业中的应用效果,在丁苯橡胶中进行了填充实验并研究采用超细粉替代垫带胶配方中的炭黑的可行性。实验发现,加入无机超细粉的丁苯橡胶的硬度、拉伸强度、撕裂强度与加入炭黑的相比均比较小,只有扯断伸长率相对比较大,说明无机超细粉只起填充作用;将超细粉用在垫带胶中,当原有的40份炭黑N330用20份的无机超细粉替代时可以满足垫带胶的性能要求,即无机超细粉可以部分替代炭黑N330用于垫带胶中,降低胶料的成本,增加效益,同时达到保护环境的目的。     

超细矿渣微粉对硅酸盐水泥性能影响研究

用超细矿渣微粉取代不同量水泥,研究超细矿渣微粉对水泥砂浆流动度,力学性能,干燥收缩及其抗冻性的影响,结合XRD结果说明超细矿渣微粉对水泥浆体早期水化的影响。结果显示超细矿渣微粉具有高活性,可以加速早期水泥水化,适量的取代水泥用量,提高水泥基材料的机械性能及耐久性,可以作为掺和料加入水泥基材料。     

Properties of surface‐modified multiwalled carbon nanotube filled poly(ethylene terephthalate) composite films

Poly(ethylene terephthalate) (PET)/multiwalled carbon nanotube (MWCNT) composites were prepared by in situ polymerization. To improve the dispersion of MWCNTs in the PET matrix, functionalized MWCNTs having acid groups (acid‐MWCNTs) and acetic groups (acetic‐MWCNTs) on their surfaces were used. The functional groups were confirmed by infrared spectrometry. Scanning electron microscopy showed that acetic‐MWCNTs had a better dispersion in the PET matrix than pristine MWCNTs and acid‐MWCNTs. A reaction between PET and acetic‐MWCNTs was confirmed by a shift of the Raman G band to a higher frequency and an increase of the complex viscosity in the rheological properties. The composites containing functionalized MWCNTs showed a large increase in their tensile strengths and moduli. The values of the strengths and moduli of the PET/acetic‐MWCNT composites were higher than those of the PET/acid‐MWCNT composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008