活化废轿车轮胎胶粉及其改性沥青的基本性能

采用双螺杆挤出机辅以活化剂制备活化废轿车轮胎胶粉(GTR),用其改性沥青或与苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)复合改性沥青。研究了活化GTR的溶胶、凝胶含量,考察了活化GTR改性沥青和活化GTR/SBS复合改性沥青的基本性能及微观形貌。结果表明,热剪切以及添加活化剂均能提高GTR的溶胶含量,使脱硫降解程度增大;用活化GTR改性沥青,改性沥青的针入度大幅增大,软化点、弹性回复、黏度明显降低;用活化GTR/SBS复合改性沥青,随着活化GTR含量的增大,改性沥青的软化点升高,针入度、延度、弹性回复降低,但经旋转薄膜老化后延度提高,耐老化性能提高;活化GTR在沥青中的粒径明显减小,分散性得到改善,而活化GTR/SBS复合改性沥青时,GTR均匀分散于SBS的网络结构中。     

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。     

SBS对沥青性能的影响

通过测试软化点、针入度和延度对SBS改性沥青的性能进行表征.结果表明:使用线型或星型SBS作为沥青改性剂可以显著提高沥青性能.当硫黄稳定剂质量分数为0.2％,SBS质量分数为4％时,改性沥青的软化点、针入度和延度趋于稳定.此外,相较于线型SBS改性,星型SBS改性沥青的软化点稍高,针入度和延度相对更小.     

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     

响应面法优化制备LDHs-CRMA复合改性沥青及其表征

采用熔融共混法,以克拉玛依90^#沥青为原料,Mg-Al水滑石(LDHs)与废橡胶粉(CR)作为改性剂,制备了具有抗紫外老化性能的水滑石/废胶粉复合改性沥青(LDHs/CRMA),并对其软化点、针入度指数(PI)、延度进行了测试。通过Hassan数学方法将三个指标“归一化”得到总评“归一值”,采用响应面分析法建立总评“归一值”与各因素之间的Box-Behnken数学模型,得到了LDHs/CRMA的最优制备工艺条件为：剪切温度173℃、剪切时间89 min、剪切速率3500 r/min。通过紫外老化模拟实验对复合改性沥青的抗老化性能进行了评价,结果表明,引入水滑石可以减少沥青老化过程中含氧官能团的产生,抗紫外老化性能得到了明显提高。     

The Effect of Epoxidized Natural Rubber (ENR-50) or Polyethylene Acrylic Acid (PEA) as Compatibilizer on Properties of Ethylene Vinyl Acetate (EVA)/Natural Rubber (SMR L) Blends

The effect of epoxidized natural rubber (ENR) or polyethylene acrylic acid (PEA) as a compatibilizer on properties of ethylene vinyl acetate (EVA)/natural rubber (SMR L) blends was studied. 5 wt.% of compatibilizer was employed in EVA/SMR L blend and the effect of compatibilizer on tensile properties, thermal properties, swelling resistance, and morphological properties were investigated. Blends were prepared by using a laboratory scale of internal mixer at 120°C with 50 rpm of rotor speed. Tensile properties, thermal properties, thermo-oxidative aging resistance, and oil swell resistance were determined according to related ASTM standards. The compatibility of EVA/SMR L blends with 5 wt.% of compatibilizer addition or without compatibilizing agent was compared. The EVA/SMR L blend with compatibilizer shows substantially improvement in tensile properties compared to the EVA/SMR L blend without compatibilizer. Compatibilization had reduced interfacial tension and domain size of ethylene vinyl acetate (EVA)/natural rubber (SMR L) blends.     

SBS改性沥青的结构与性能

通过动态黏弹性能、结构分析和沥青基本性能测试研究了SBS和沥青之间的相容性,以及SBS用量对改性沥青的结构与性能的影响。结果表明,SBS与沥青有一定的相容性,沥青中的某些组分可进入SBS的聚丁二烯(PB)链段区域。使PB的玻璃化转变温度升高,在高剪切力作用下也可进入聚苯乙烯(PS)链段,降低了PS的玻璃化转变温度,但不会使PS物理交联点发生严重解体。当SBS质量分数为5％时,SBS在沥青中呈彼此分离的球状颗粒;当SBS质量分数达到7％或以上时,则形成连续相。随着SBS质量分数的增加。改性沥青的软化点和低温延度升高,针入度和高温贮存稳定性下降。     

Comparison Properties of Natural Rubber (SMR L)/Ethylene Vinyl Acetate (EVA) Copolymer Blends and Epoxidized Natural Rubber (ENR-50)/Ethylene Vinyl Acetate (EVA) Copolymer Blends

Mixing torque, morphology, tensile properties and swelling studies of natural rubber/ethylene vinyl acetate copolymer blends were studied. Two series of unvulcanized blends, natural rubber/ethylene vinyl acetate (SMRL/EVA) copolymer blend and epoxidized natural rubber (50% epoxidation)/ethylene vinyl acetate (ENR-50/EVA) copolymer blend were prepared. Blends were prepared using a laboratory internal mixer, Haake Rheomix polydrive with rotor speed of 50 rpm at 120°C. Results indicated that mixing torque value and stabilization torque value in ENR-50 blends are lower than SMRL blends. The process efficiency of ENR-50/EVA blends is better due to less viscous nature of the blend compared to SMRL/EVA blends as indicated in stabilization torque graph. Tensile properties like tensile strength, M100 (modulus at 100% elongation) and E _b (elongation at break) increase with increasing EVA fraction in the blend. At the similar blend composition, ENR-50 blend shows better tensile properties than SMRL blends. In oil resistance test, swelling percentage increased with immersion time and rubber composition. At a similar immersion time, ENR-50 blends exhibit better oil resistance compared to SMRL blends. Scanning electron microscopy (SEM) of tensile fractured surface indicated that EVA/ENR-50 blends need higher energy to cause catastrophic failure compared to EVA/SMRL blends. In etched cryogenically fractured surface, size and distribution of holes due to extraction of rubber phase by methyl ethyl ketone (MEK) were studied and holes became bigger as rubber composition increased due to coalescence of rubber particle.     

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。     

纳米有机膨润土/丁苯橡胶复合改性沥青的制备及性能

以纳米有机膨润土和丁苯橡胶(SBR)制备复合改性沥青,并考察了复合改性沥青的针入度、软化点、延度、储存稳定性及流变性能,同时对比了液体SBR和粉末SBR对复合改性沥青性能的影响.结果表明,复合改性沥青中,纳米有机膨润土的最佳质量分数为4％.随着SBR用量的增加,沥青的针入度降低,软化点升高,延度先增大后减小.粉末SBR...     

SBS改性沥青的基本性能的实验研究

利用SBS对AH-90沥青进行了改性研究,并对改性沥青的软化点、延度、针入度等性能进行表征.结果表明,随着SBS用量的增加,改性沥青的软化点上升,针入度降低,延度增加;但是当SBS用量增加至6%时,针入度降至国家标准以下.因此,SBS用量在4.5%～5.5%时,改性沥青的软化点、延度、针入度等基本性能最好.     

一种胶粉改性沥青降粘剂的研究

采用硬脂酸酰胺作为胶粉改性沥青混合时的降粘剂,从而改善胶粉改性沥青的流动性,降低胶粉改性沥青的混合温度。利用Brookfield沥青粘度仪跟踪添加降粘剂后胶粉改性沥青粘度,测试添加降粘剂后改性沥青3大性能指标即软化点、针入度和延度,从沥青四组分角度对降粘机理进行分析。结果表明:硬脂酸酰胺对改性沥青降粘效果明显,从而可以降低改性沥青的加工温度。同时对性能指标有一定影响,在135℃达到降粘与性能的最佳平衡。     

脱硫胶粉在乳化改性沥青中的应用

考察了不同规格胶粉及不同脱硫程度的脱硫胶粉对橡胶改性乳化沥青性能的影响,结果表明,采用100目胶粉即可制备出橡胶改性乳化沥青,但乳化沥青的性能较差;采用活化度为50%左右的100目脱硫胶粉制备乳化沥青时,脱硫胶粉的用量相比于胶粉可大幅提高;在通过外掺100目50%左右活化度的脱硫胶粉(质量分数15%,以沥青计,下同)和质量分数2%的苯乙烯-丁二烯-苯乙烯嵌段共聚物改性的乳化沥青中添加质量分数1%的丁苯胶乳,所制备橡胶改性乳化沥青无筛上剩余物,5 d储存稳定性为2.9%,蒸发残留物的25℃针入度、软化点和5℃延度分别为55 (0.1 mm)、64.5℃和22.5 cm,能够满足乳化改性沥青的技术指标要求。     

Investigation of physiochemical and rheological properties of waste cooking oil/SBS/EVA composite modified petroleum asphalt

The objective of this research is to investigate the physiochemical and rheological properties of waste cooking oil (WCO)/styrene-b-butadiene-b-styrene/ethylene vinyl acetate (SBS/EVA) composite modified asphalt. A petroleum asphalt composite modified with SBS/EVA and oil/SBS/EVA were prepared to undergo the physical, rheological, and microscopic experiments. Comparing these tests results with the properties of unmodified petroleum asphalt, SBS and EVA cause an improvement in pavement performance, but weaken the storage stability. Although the high-temperature performance undermined by the addition of WCO, the thermal stability, fatigue property, and low temperature crack resistance improved obviously. In addition, WCO mainly composed by low-weight components, and these can supplement the light components in the polymer-modified asphalt. EVA could increase the percentage of large molecular size of asphalt, while WCO relieves this trend. The reactions between WCO and these polymers (SBS and EVA) are physical reactions. Atomic force microscopy morphology results reflect that SBS and EVA increase the surface complexity and roughness, and WCO makes the asphalt surface smooth. This indicates WCO increases the dispersion of polymers in asphalt. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48828.     

马来酸酐对SBS改性沥青的性能影响

分析了马来酸酐（MAH）不同掺量对SBS改性沥青微观结构和性能的影响。结果表明,随MAH掺量的增加,SBS改性沥青的软化点和针人度指数PI提高,但5℃延度降低。而改性沥青离析软化点差随MAH掺量增加,先减小后增大,表明相容性先改善后变差。     

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.     

Influence of Polymer Type and Structure on Polymer Modified Asphalt Concrete Mix

Two low‐density polyethylene (LDPE) resins and two ethyl vinyl acetate (EVA) polymers were used to modify asphalt binder, and then mixed with asphalt concrete according to Marshall Method of mix design (ASTM D 1559). Effect of weight average molecular weight (M_w) of LDPE and vinyl acetate (VA) content of EVA was studied by performing Marshall Stability, moisture susceptibility (AASHTO T 283‐89), resilient modulus (M_R) and permanent deformation (rutting) tests. EVA with low VA content showed lower stability loss in Marshall Stability test and improved resistance in moisture susceptibility test in comparison to hot mix asphalt concrete mix (HMA) and other polymer modified asphalt concrete mixes (PMAMs). Higher M_R and better rutting resistance were observed for PMAMs than that of HMA. This elastic behaviour of modified asphalt correlates very well with the M_R and rutting resistance properties of PMAM.     

Plastification of poly(vinyl chloride) by polymer blending

Blends of poly(vinyl chloride) (PVC) with different copolymers have been studied to obtain a plasticized PVC with improved properties and the absence of plasticizer migration. The copolymers used as plasticizers in the blends were acrylonitrile butadiene rubber, ethylene vinyl acetate (EVA), and ethylene-acrylic copolymer (E-Acry). Blends were studied with regard to their processing, miscibility, and mechanical properties, as a function of blend and copolymer composition. The results obtained were compared with those of equivalent compositions in the PVC/dioctyl phthalate (DOP) system. Better results than PVC/DOP were obtained for PVC/acrylonitrile butadiene rubber blends. The plasticizing effect on PVC of EVA and E-Acry copolymers was similar to that of DOP. It is shown that crosslinking PVC/E-Acry blends or increasing the vinyl acetate content in PVC/EVA blends, are alternatives that can increase the compatibility and mechanical properties of these blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1303–1312, 2000     

Characterization of eva-based adhesives containing different amounts of rosin ester or polyterpene tackifier

Different amounts (50-170 php--parts per hundred parts of EVA, 33-63 wt%) of two tackifiers (hydrogenated rosin ester, polyterpene resin) were added to an ethylene vinyl acetate (EVA) copolymer containing 28 wt% vinyl acetate. The EVA and the tackifier were characterized using infrared (IR) spectroscopy, DSC measurements, and stress-controlled plate-plate rheology. The properties and compatibility of the EVA-tackifier mixtures were studied using DSC, DMTA, and stress-controlled plate-plate rheology. Immediate adhesion was measured as a quantification of tack, and the T-peel strength of roughened styrene-butadiene rubber/EVA-tackifier adhesive joints was also obtained. The increase in the amount of tackifier noticeably changed the crystallinity of polyethylene blocks in the EVA, and the temperature at the cross-over between the curves of the storage and loss moduli as a function of the temperature was displaced to a lower value. Whereas the hydrogenated rosin ester was compatible with the amorphous ethylene vinyl acetate copolymer regions of the EVA (Tg value increased) reducing its crystallinity, the polyterpene resin was compatible with the polyethylene blocks of the EVA (T g value was not modified), increasing its crystallinity. Immediate adhesion of the EVA-tackifier mixtures was improved by adding both hydrogenated rosin ester and polyterpene tackifiers. On the other hand, there was an optimum tackifier content at which the maximum T-peel strength value was obtained.     

废旧SBS改性沥青再生利用研究

以欢喜岭AH-90沥青为基质沥青,采用添加SBS改性剂的方法制得SBS改性沥青。其针入度、软化点、延度等指标符合JTJ036—98I-C标准,对其进行第一次老化,制得废旧SBS改性沥青。对废旧SBS改性沥青再加入适量的再生剂和SBR,使废旧SBS改性沥青的理化指标重新恢复到JTJ036—98I-C标准的要求,制得再生SBS改性沥青,再对其进行第二次老化。结果表明废旧SBS改性沥青可以通过再生的方法加以重新利用。