Modification of asphalt by packaging waste‐polyethylene

The “white pollution” made of packaging waste polymers and its recycling has become a common issue. In this article, the retrieved waste milk‐packing bag (its main ingredients was polyethylene) was selected to modify the ordinary oil asphalt. Asphalt was modified with 1, 3, 6, and 9 wt% content of waste‐polyethylene. The results showed that the softening point and the freeze‐to‐crack stress of asphalt increased the penetration and the freeze‐to‐crack temperature decreased after modification. The comprehensive performance of raw asphalt improved noticeably. Infrared analysis suggests that waste‐polyethylene in packaging (WPE) combines the matrix of asphalt through physical mixture modification. And the modification mechanism of WPE was studied by the analysis of its micro structure, the characteristics of WPE, the effects of Crack pinning and Silver Shear yield in the decentralized process. Using waste packaging polymers to modify the asphalt proved to be an ideal way, for not only solving the problem of “white pollution”, but also for improving the performance of asphalt. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Pavement properties of asphalt modified with packaging‐waste polyethylene

Recycled packaging‐waste polyethylene (WPE) was used to replace the ordinary polymer modifier in the modification of raw asphalt, and the pavement properties of the modified asphalt were studied. The high‐temperature stability, anti‐cracking properties at low temperature, life span, and stability against water of the asphalt mixture were improved, a finding which is attributed to the properties and characteristics of WPE, the swelling of sheared WPE, and the WPE/asphalt network structure. The use of packaging WPE can improve the pavement properties of asphalt, as well as save resources and reduce white pollution. J. VINYL ADDIT. TECHNOL., 20:31–35, 2014. © 2014 Society of Plastics Engineers     

Effect of organic montmorillonite on the hot storage stability of asphalt modified by waste packaging polyethylene

In this paper, waste polyethylene (WPE), a large class of waste plastic packaging, and organic montmorillonite (OMMT) were employed as the polymer modifier and additive to modify base asphalt, and then hot storage stability of modified asphalt was studied. Structure of the modified asphalt was characterized with X‐ray diffraction and fluorescence microscopy. Moreover, the hot storage stability of WPE‐modified asphalt was investigated by Fourier‐transform infrared analysis, differential scanning calorimetry, and thermal gravimetry. Results show that an exfoliated structure is formed in the modified asphalt after adding OMMT. The WPE modifier particles become smaller and are more uniformly dispersed in the modified asphalt system after adding OMMT. Also, the addition of OMMT effectively improves the hot storage stability of the modified asphalt. The OMMT not only increases the compatibility between the WPE modifier and base asphalt but enhances the homogeneity of the modified asphalt at extreme temperatures. Heat capacity and phase behavior of modified asphalt after adding OMMT are changed; in the meantime, the thermal stability of the modified asphalt increases. J. VINYL ADDIT. TECHNOL., 21:89–93, 2015. © 2014 Society of Plastics Engineers     

Rheological properties of packaging‐waste‐polyethylene‐modified asphalt

Waste‐polyethylene (WPE) in packaging, instead of virgin polymer, was utilized as a modifier of base asphalt, and rheological properties of the modified asphalt were studied. Results show that the modified asphalt possesses better anti‐distortion capacity than the base asphalt, as indicated by the fact that the modified asphalt has higher viscosity and smaller endothermic peak dispersion in the transformation process of asphalt aggregation. Compared with base asphalt, the modified asphalt has higher complex modulus (G*), storage modulus (G′), and dissipation modulus (G″). In addition, the modified asphalt has smaller phase angle (δ), less tangent (tanδ), and lower rut factor (G*/sinδ), reflecting the high‐temperature rut resistance of the asphalt. The improvement of the rheological properties is related to the main features of the modified asphalt, including the swelling, whereas packaging‐waste‐PE absorbs low‐molecular‐weight fractions of asphalt, the displacement restriction of asphalt particles, and the molecular structure and performance of PE molecules. J. VINYL ADDIT. TECHNOL., 21:215–219, 2015. © 2014 Society of Plastics Engineers     

Modification of waterproofing asphalt by PVC packaging waste

Recycled packaging waste poly(vinyl chloride), instead of an ordinary polymer modifier, was adopted for the modification of an asphalt waterproofing membrane. The physical performance of the membrane was studied. Results showed that the softening point of the modified asphalt was increased, while the penetration degree was reduced. Also, under natural aging conditions, the tension, the retention of extension under the greatest tension, and the retention of low‐temperature flexibility were all improved significantly. At the same time, the resistance to acid, alkali, and salt corrosion of the modified waterproofing membrane was improved. The mechanism of the modification was studied by Fourier transform infrared spectroscopy and microstructure analysis. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

橡塑合金改性沥青制备工艺关键参数研究

为了合理、有效地利用废旧橡胶粉和废旧塑料并改善两者与沥青的相容性,采用精密开炼机预先将两种废旧材料熔融共混,制备成橡塑（质量）比分别为5∶5（Ⅰ型）、6∶4（Ⅱ型）、和7∶3（Ⅲ型）3种橡塑合金改性剂。按照正交试验方案对伦特70^#基质沥青进行改性,制备橡塑合金改性沥青,以橡塑合金改性沥青的48 h离析软化点、25 ℃针入度、软化点和5 ℃延度为指标,筛选橡塑合金改性沥青的最佳复配方案,并通过灰色关联度分析法和极差分析法确定制备工艺最佳的关键参数。最后通过扫描电子显微镜、布氏旋转黏度试验、BBR试验和DSR试验对橡塑合金改性沥青的结构形态、流变性能、低温抗裂性能和抗疲劳性能进行了分析。结果表明：最佳复配方案为外掺20 %（相较于基质沥青质量）橡塑比为7∶3（Ⅲ型）的橡塑合金、2 %增溶剂（糠醛抽出油）和9 %稳定剂（硫磺）,制备的橡塑合金改性沥青储存稳定性和高温稳定性良好,推荐制备工艺的最佳关键参数为剪切温度180 ℃、剪切速率3 500 r/min、剪切时间1.5 h和发育时间0.5 h;橡塑合金改性剂与沥青的相容性好,制备的橡塑合金改性沥青具有较低的温度敏感性,较好的低温抗裂性和抗疲劳性能。     

Study on percolation phenomena and mechanism of enhanced asphalt by polymers

Abstract

The properties of asphalt modified by styrene–butadiene–styrene, polyvinyl acetate and waste crumb rubber separately in a wide range of polymer loadings were studied in this paper. In analysing the relationship between polymer loading and modified asphalt properties, we found that the ductility of polymer modified asphalt measured at 5°C exhibited a percolation phenomenon, that is, as the loading of polymer exceeded a critical value, the ductility of modified asphalt changed abruptly. Furthermore, a percolation threshold differential existed. A rubber processing analyser, an optical microscope and a fluorescence microscope were used to characterise the microstructure of polymer modified asphalt and validate the occurrence of a polymer network in modified asphalt as a function of polymer loading. The percolation phenomenon of polymer modified asphalt was found to be associated with the polymer network in modified asphalt and can be well explained by the percolation mechanism of rubber toughened plastics.     

常温粉体涂覆母料法对改性道路沥青性能的影响

采用软化点、针入度和延度等作为道路沥青性能的衡量指标,主要研究了废胶粉的热处理后对于改性沥青性能的影响。为此,笔者用热处理废胶粉的方法改变胶粉的某些性质,然后改变一些处理条件,与沥青进行相混。相比较沥青改性前后的三大指标,分析其改性效果。研究发现,胶粉的热处理能够一定程度地改善沥青性能。     

Utilization of sulfur and crumb rubber in asphalt modification

In this study, waste crumb rubber and sulfur were utilized to enhance the performance of asphalt binder for pavement applications. About 20–50% of sulfur and 1–6% crumb rubber were used. Melt properties were investigated using thermal analysis, dynamic and steady shear rheology, and artificial aging. Rheological tests were carried out in ARES rheometer. Both steady and dynamic shear rheology showed that crumb rubber improved the viscoelastic properties of the sulfur‐extended asphalt binder. Crumb rubber modification reduced temperature susceptibility of sulfur/asphalt, and increased the upper grading (performance) temperature of sulfur asphalt. The combined effect of sulfur and crumb rubber reduced the activation energy compared with that of pure asphalt. Zero‐shear viscosity and strategic highway research program rutting parameter (G*/sinδ) improved by crumb rubber incorporation into the sulfur asphalt binder. Short‐term aging improved G*/sinδ with slight increase in activation energy. The addition of sulfur to asphalt matrix increased the viscoelastic properties (G′ and G″) of sulfur asphalt. The addition of crumb rubber to sulfur asphalt enhanced the temperature resistance of the binder. Utilization of waste crumb rubber and sulfur in asphalt modification proved to enhance asphalt pavement life. In addition, utilization of such wastes can help in meeting the extra demand for asphalt, reduce the pavement cost, and help in solving a waste disposal problem. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40046.     

Optimization of the modification technologies of asphalt by using waste EVA from packaging

Packaging wastes not only pollute the environment, but also waste resources. In this study, bags of suits made mainly from ethylene(vinyl acetate) copolymer (EVA), as the modifier, were used to improve the properties of raw asphalt. On the basis of the common physical modification, crosslinking agents and catalysts were added to the raw oil asphalt. The modification technologies were studied carefully. The results showed that crosslinking agents and catalysts could make the polymer react with raw asphalt, thus providing chemical connections between them and forming three‐dimensional network structures. As a result, the asphalt performance was improved. In addition, the dosages of the crosslinking agent, modification temperature, and time also had effects on the performance of the modified asphalt. When the ratio of divinylbenzene to asphalt was 0.0125, the ratio of catalyst to asphalt was 0.025, the temperature was 140°C, and the modification time was 2.5 h, the softening point of the asphalt rose from 49.5°C to 63.5°C, and the penetration degree dropped from 68.5 to 39.1 (0.1 mm). The results showed that after the modification with waste EVA, the performance of the asphalt had been significantly improved and stabilized. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

综述WRP、SBR、SBS改性沥青制备方法和性能的比较

介绍了目前国内在制备改性沥青方面的三种常用方法:废橡胶粉WRP改性沥青、SBR改性沥青、SBS改性沥青,并对这三种方法的改性机理作了简要叙述,对由这三种方法制备的改性沥青的性能做了对比。因此可根据实际情况选择不同的改性方法。     

废旧塑料改性沥青相容性的研究

研究了废旧塑料改性沥青相容性方面的问题,指出了废旧塑料作用于沥青改性的潜在价值,在当前技术条件支持下,对常见的沥青聚合物改性剂类型及其改性效果进行了阐述,最后分析了影响废旧塑料改性沥青相容性的主要因素,可在今后的工作中进一步研究与论证。     

Effect of electron beam irradiation on the mechanical,thermal, and dynamic mechanical properties of flyash and nanostructured fly ash waste polyethylene hybrid composites

The effect of electron beam irradiation on the technical properties of fly ash (FA) and nano fly ash (NFA)‐filled waste polyethylene (WPE) composites have been investigated in this article. It is observed that the FA/NFA at 5 wt% imparted enhanced technical properties. The modified composites were prepared by three different methods (1) modification of WPE matrix first by grafting with maleic anhydride (MA) and preparing the composite (2) Preparing WPE‐FA/NFA composites and subjecting to electron beam irradiation. (3) Subjecting the FA/NFA to electron beam radiation first and then preparing composites with WPE. Of the three methods, the composite prepared and then electron beam irradiated gave the best balance in the physico‐mechanical properties. The tensile and flexural strength of WPE increased from 21.2 MPa and 25.4 MPa to 33.0 MPa (57.8%) and 45.8 MPa (72%) respectively at 5 wt% FA‐filled WPE composites, which further increased to 34.5 MPa (65%) and 47.7 MPa (87.8%) respectively with 5 wt% of NFA‐filled WPE composites, after electron beam irradiation. The thermal stability was enhanced upon electron beam irradiation of the composites. The dynamic mechanical properties reveal that the storage modulus reaches the highest value for the irradiated composite corroborating with the flexural modulus throughout the temperature range studied. The fractured surfaces were examined under SEM and were correlated with the mechanical properties. The results indicate that FA/NFA reinforced WPE composites act as an excellent stress raisers preventing crack propagation and enhancing the performance properties on electron beam irradiation. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers     

废弃玻璃钢粉改性沥青材料制备与性能研究

为提高玻璃钢（GFRP）管道废弃物的利用率,研究了废弃GFRP粉粒径、掺量及剪切制度（温度、时间、速率）对改性沥青延度、针入度及软化点的影响规律,利用偏光显微镜（PLM）、红外光谱仪（FTIR）分析了其微观结构。结果表明,废弃GFRP中热固性树脂可与沥青反应生成环烷烃和脂肪烃,其中脂肪烃含量增加将提高沥青延度,废弃GFRP掺量过高则环烷烃含量增加,不利于沥青延度提升;玻璃纤维可降低沥青针入度和提高其高温稳定性,掺量过高却会形成更多缺陷致使延度下降,但有利于沥青硬度提高;剪切温度过低或过高时,改性沥青中形成的环烷烃含量均升高,不利于沥青延度提升,但剪切温度对改性沥青高温稳定性影响不显著;当剪切机转速达到一定值时,增加剪切机转速对改性沥青性能影响较小,而延长剪切时间却有利于其性能提高;最佳改性制度为粒径<0.3 mm、掺量4 %、改性温度150 ℃、剪切时间4 h、剪切机转速8 000 r/min。     

Gamma irradiation of (styrene butadiene rubber)/(devulcanized waste rubber) blends modified by organoclay

In this study, the physicomechanical properties and morphology evolution of irradiated (styrene butadiene rubber)/(devulcanized waste rubber)/(organically modified montmorillonite) nanocomposites were realized. The improvement in the physicomechanical properties provides a possible mechanism on how organically modified montmorillonite influences the general properties of irradiated nanocomposites. X‐ray diffraction data illustrated that there is an increase in the basal spacing of sodium montmorillonite clay due to modification and/or polymer intercalation. The results of mechanical properties showed that the as‐prepared nanocomposites have superior irradiation‐resistant properties to the (styrene butadiene rubber)/(devulcanized waste rubber) blend. J. VINYL ADDIT. TECHNOL., 24:50–57, 2018. © 2015 Society of Plastics Engineers     

Characterization of air-blown asphalt/trans-polyoctenamer rubber blends

Air-blown asphalt (ABA) was modified by blending with trans-polyoctenamer rubber (TOR). The thermal properties examined by differential scanning calorimetry indicated that flexible aliphatic hydrocarbons in maltene phase or paraffin wax, preferentially dissolved into the TOR phase from the ABA phase. Rheological properties examined with a rheometer by frequency sweep and temperature sweep suggested that the polymer modified asphalt is a multiphase system composed of a phase formed by maltenes, a mesoscopic phase rich in asphaltenes, and a TOR phase swelled by dissolved maltenes. The elasticity, modulus, and the temperature susceptibility of ABA were improved by modification with TOR.     

废橡胶粉改性沥青性能的研究

以克拉玛依A H-110沥青为基体,废橡胶粉为改性剂,采用湿法共混,在溶胀时间为2 h,剪切时间为1.5 h,剪切温度为186℃,剪切速率为7 000 r/min的条件下,制备出高性能废胶粉改性沥青。通过改变胶粉的用量和胶粉的粒径,研究了胶粉对改性沥青性能的影响,探讨了胶粉改性沥青机理。结果表明:废橡胶粉的掺入使沥青的软化点、针入度、延度都有明显改善。研究发现废橡胶粉的最佳掺量为15%,最佳粒径为80目。     

废旧轮胎橡胶粉/苯乙烯-丁二烯-苯乙烯嵌段共聚物/石油树脂复合改性沥青的制备及性能

以苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）、废旧轮胎橡胶粉和石油树脂制备复合改性沥青,并对复合改性沥青的储存稳定性、温度敏感性、高温流变性能、抗车辙性能和黏度等进行了考察。结果表明,复合改性沥青中,SBS、废旧轮胎橡胶粉及石油树脂的最佳质量分数分别为4.5%、14.0%和4.5%;石油树脂/SBS/废旧轮胎橡胶粉复合改性沥青具有较好的储存稳定性、温度敏感性和抗车辙性能。     

中海油36-1橡胶改性沥青的研制

文章采用橡胶粉、SBS等对中海36-1 AH-90重交道路沥青进行改性制备橡胶改性沥青,并考察了橡胶粉、SBS掺量以及工艺条件参数等对橡胶改性沥青性能的影响。研究结果表明,改性温度为190-210℃,改性时间5h,能够制备符合中海油36-1橡胶改性沥青标准的产品。     

Effects of polyphosphoric acid (PPA), styrene-butadiene-styrene (SBS), or rock asphalt on the performance of desulfurized rubber modified asphalt

To improve the performance of desulfurized rubber modified asphalt (DRMA), especially its high-temperature performance, three modifiers (including polyphosphoric acid [PPA], styrene-butadiene-styrene [SBS], and rock asphalt) were selected to modify DRMA respectively. The conventional performance, rheological properties, chemical composition, and thermal decomposition were characterized to analyze the performance and modification mechanism of DRMA and its composites. Test results show that, the addition of PPA, SBS, and rock asphalt can all improve the high temperature of DRMA, among which the desulfurized rubber/rock asphalt compound modified asphalt (DRMA-ROCK) has the best high-temperature performance; however, its construction workability, storage stability, and low-temperature performance are poor. In contrast, desulfurized rubber/PPA compound modified asphalt (DRMA-PPA) not only has better high-temperature performance, but also has excellent low-temperature performance, storage stability, and fatigue performance. Fourier infrared spectroscopy (FTIR) test confirms that the modification process of DRMA by these modifiers is chemical modification, and the characteristic peak indexes obtained from FTIR also prove that DRMA-ROCK has better high-temperature performance but poor construction workability from the microscopic point of view. Furthermore, thermogravimetric analysis-differential scanning calorimetry test shows that the addition of rock asphalt improves the thermal stability of DRMA, while PPA and SBS decrease its thermal stability. From the above results, it can be concluded that DRMA-PPA has excellent comprehensive properties.