The Viscosity-reducing Mechanism of Organic Wax Additive on CRMA

CRMA was prepared by mixing PG 64-22 asphalt with crumb rubber powder of 40 mesh size and 18% by weight of the asphalt. Sasobit, a typical organic wax additive, was selected and added into CRMA. A series of tests, namely, brookfield viscosity, environmental scanning electron microscope（ESEM）, component test, differential scanning calorimeter（DSC）, fourier transform infrared spectroscopy （FTIR） and nuclear magnetic resonance （NMR） were conducted on CRMA with and without organic wax additive, and microcosmic appearance, component content and molecular structure of various asphalt binders were obtained. The test results indicate that the addition of Sasobit~ into CRMA can effectively change the contents of components： the content of asphaltenes increases relatively, while saturates decreases. In addition, the interaction between various components of CRMA is weakened, and the state of equilibrium between the dispersant and dispersed phase is changed at the same time. That is why the viscosity decreases after the organic wax additive is added into CRMA.

A novel polyionic liquid with lubricity and viscosity-increasing dual functionalities as the additive in aqueous lubrication system

The polyionic liquid poly-PEGMA-r-METAC(PPM)with quaternary ammonium has been synthesized and evaluated as additive in aqueous lubricating fluids.The rheological behavior of aqueous lubricating fluids with PPM has been characterized to confirm PPM’s function as a viscosity modifier.The tribological behavior of aqueous lubricating fluids with PPM has been investigated on SRV-V and MTM testing machines.It was found that PPM has excellent viscosity-increasing,lubricating,and anti-wear properties as an additive for aqueous,which can be attributed to the ability of PPM to form the protective film and boundary tribofilm generated from complex tribochemical reaction on rubbing surface.The obtained PPM with dual functions of anti-corrosion additives and viscosity index improver can play an important role in diverse lubrication regimes.

Effects of slurry viscosity and particle additive size on filter cake formation in highly permeable sand

Filter cake is critical to maintaining the stability of the excavation face of an underwater shield tunnel in a high-permeability stratum.In a high-permeability formation,generating an effective filter cake on the excavation face is difficult with a pure bentonite slurry,which penetrates the ground and may not achieve the required suspension pressure.Determining how to efficiently and quickly form a thin and low-permeability filter cake on the tunnel working face has become a key engineering problem in the construction of slurry shield tunnels in high-permeability strata.In this study,the relationship between slurry viscosity and the slurry pressure gradient of pure bentonite was established by performing slurry permeability experiments.The influence of slurry viscosity on the formation of the filter cake in a high-permeability formation was studied under different pressure gradients.In addition,the effect of additive particle size on the slurry filter cake formation was analyzed by introducing additives with different particle sizes to pure bentonite slurries with different viscosities.The test results indicate that(1)for the pure bentonite slurry,the critical initial pressure gradient can be used as a rough indicator of the formation of the filter cake,and the relationship between the critical maximum pore diameter and the average pore diameter of the for-mation can be compared to establish and analyze the formation law of the slurry filter cake;(2)adding particles to the slurry can enhance the effect of the pure bentonite slurry;and(3)adding coarse-grained materials can effectively improve the film-forming effect.The slurry is more compact when the particle size is close to the average pore size of the formation.

Effect of Short Chain Alcohols upon Viscosity of TTAB Solution

The effect of ethanol （C2H5OH）, propanol （C3H7OH）, and butanol （C4H9OH） upon the viscosity of tetradecyltrimethylammonium bromide （TTAB） solution in the presence or absence of KBr at 30℃was investigated, where the surfactant concentration CS is kept constant. In the absence of KBr, the relative viscosity ηr of TTAB solution increases linearly with the alcohol concentration CA, indicating that the alcohols do not promote micelle formation of TTAB. In the presence of KBr, ηr linearly decreases with CA for C2H5OH, but it exhibits a maximum with increasing CA for C3H7OH or C4H9OH. The facts reveal that C2H5OH or C4H9OH promotes the micelle formation of TTAB. A possible explanation is that the hydrophobicity of the mieellar interior is enhanced by KBr, so that C2H5OH or C4H9OH can dissolve in micelle and promotes micelle formation. In the presence of KCl, which is less efficient in promoting the micelle formation of cationic surfactant, both C3H7OH and C4H9OH have only a slight effect on the micelle formation. In contrast, due to the hydrophilicity, C2H5OH cannot dissolve in micelles in the presence of KBr or KCl.

Influence of conductive additive on temperature susceptibility of asphalt binders

The effects of graphite on temperature susceptibility of asphalt binders were investigated by penetration test,Ring & Ball softening point test and viscosity test.And penetration index(IP),viscosity-temperature susceptibility(SVT),and penetration-viscosity numbers(NPV) were introduced to evaluate the effects.The results show that the penetration,softening point and viscosity of asphalt binder increase with the increase of content of graphite.This means that the addition of graphite makes asphalts stiffer.The results from IP,NPV and SVT show that temperature susceptibility is reduced by the addition of graphite.

ASSOCIATION OF ETHYLENE VINYL ACETATE COPOLYMER IN DILUTE SOLUTIONS IV. SOLVENT MIXTURE AND ADDITIVE EFFECT ON C_A

Critical association concentration (Ca) of ethylene-vinyl acetate copolymer (EVA) in selective solvent mixtures of 1,2-dichloroethane (DCE) (polar solvent) and cyclohexane (CYH) (non-polar solvent) was investigated. DCE is a good solvent for polyvinyl acetate (PVAc) and a poor solvent for paraffin, whereas CYH is a good solvent for the paraffin and a precipitant for PVAc. Viscosities of EVA in different compositions of the solvent mixture with and without additives were measured. Viscosity results were used to determine the C-A value of the systems. It is shown that C-A was markedly dependent on the composition of the solvent mixture and concentration and structure of the additive. Solvation and competition between hydrogen bonding and micellisation were suggested for qualitative description of the changing of C-A value observed.

Rheological Study of Polymers Used as Viscosity Index Improvers for Automotive Lubricant Oils

In this work, a rheological study of automotive lubricant oils, neutral light paraffinic (NLP) and neutral medium paraffinic (NMP), additivated with two commercial viscosity index improvers-VIIs, based on hydrogenated poly (isoprene-co-styrene), at different concentrations, was carried out. The study included the determination of the kinematic viscosity of the mixtures, the calculation of the viscosity indexes and their behavior when subjected to various rheometric experiments, including stress sweep, steady state flow, creep and recovery, and temperature ramp oscillatory tests. The obtained results showed the efficacy of the additives as viscosity index improvers, enabling a significant increase in the viscosity index of the pure oils at relatively low concentrations. The determination of the storage (G’) and of the loss (G”) moduli for the mixtures oil/VII additives showed a large predominance of the viscous effect over the elastic one. Except when under low shear stress, the mixtures showed a pseudoplastic behavior, with the flow curves being adjusted to fit the Ostwald-de-Waele model (Power Law), with negative flow behavior indexes.

Characterization of recycled crumb rubber modified binders containing wax warm additives

This paper addresses the laboratory experiment of performance properties of recycled CRM binders containing artificially aged CRM binders with wax additives. The warm CRM binders were produced using two wax additives （LEADCAP and Sasobit） and then shortterm and long-term aged using the rolling thin film oven （RTFO） and pressure aging vessel （PAV） procedures. The recycled CRM binders were aged through the RTFO and PAV pro- cedures. A set of Superpave binder tests were carried out on the binders through the rotational viscometer, the dynamic shear rheometer （DSR）, and the bending beam rheometer （BBR）. In general, the results of this study indicated that （1） the addition of longterm aged （LTA） CRM binder can significantly increase the viscosity of the recycled CRM binders as expected, （2） the wax additives in recycled CRM binders were still effective to improve the viscosity and rutting properties even after experiencing the aging process, （3） the CRM binders containing wax additives showed the higher rutting resistance compared to the control CRM binders, （4） the recycled CRM binder containing wax additives was found to have less resistance to fatigue and low temperature cracking, （5） wax warm additives into the recycled CRM binders seemed to have a significant role for cracking properties, based upon their substantial amount.

单体种类对光固化增材制造5052铝合金的影响

针对光固化增材制造5052铝合金时存在的浆料不稳定、烧结体密度偏低和碳残留量较高等问题,研究了树脂单体种类对铝合金光固化增材制造的影响。结果表明,单体种类对光固化增材制造5052铝合金的成型工艺和烧结体性能具有重要影响。采用单体TMPTA或PEG400DA的铝浆黏度大于30 Pa·s,沉降时间大于120 h,成型的铝合金坯体结构完整但表面孔洞较多;采用单体PEG200DA或HDDA的铝浆黏度低于30 Pa·s,但沉降时间小于16 h,成型的铝合金坯体表面无孔洞但结构易残缺;采用单体PS-PCL的铝浆黏度低于30 Pa·s且稳定不易沉降,坯体表面无孔洞且结构完整。采用优选单体PS-PCL制备固含量55%铝浆,打印成型并烧结后,其相对密度大于95%,碳残留量相对较低(0.259 17%),断口烧结颈明显,硬度相对较高(29.94HV)。

Effect of Water Addition on Rheological Behaviour of BauxiteBased Low-cement Castables

Water addition has direct impact on castables and needs to be under control placement and properties, In this work, two rheological properties, flow resistance and torque viscosity, have been measured against time, with different water addition in the same bauxile-based LC Castable mix. The flow resistance indicates the mobility, whereas the torque viscosity dictates the stability of a castable during installation. It has been observed that with 6.0wt% water addition, such a mix possesses good vibration castable characteristics; with 6.5 wt%, it shows good self-flow castable characteristics; and with 7.0 wt%, it can be a good pumpable castable, in every case with comparable mechanical properties. While with 7.5 wt% water addition, the properties of such castable are definitively impaired.

考虑排水性能的改性沥青混合料设计及路面施工工艺

依托实际工程,通过试验对改性沥青的性能进行深入分析,进一步探讨了排水沥青路面施工工艺,得到如下结论:(1)综合考虑各项性能检测结果和经济性可知,对于SBS改性沥青而言,高黏剂(HVA)的最佳掺量为9%;(2)对于HVA掺量为9%、聚酯纤维掺量为0.1%的高黏复合改性沥青混合料,其最佳矿料级配为:m(矿粉)∶m(0~3 mm)∶m(5~10 mm)∶m(10~15 mm)=3.5%∶9%∶42%∶45.5%,最佳油石比为4.8%;(3)排水沥青混合料由于其粗集料占比大、粒径大,故需在施工中避免粗细集料离析现象的发生,严格控制拌和、运输、摊铺、压实等施工过程的质量。

SBS/SBR/HVA高黏度复合改性沥青的制备及性能研究

以基质沥青为原料,通过添加苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)、丁苯橡胶(SBR)、国产高黏度添加剂HVA制备了适合排水路面使用的高黏度复合改性沥青,以60℃动力黏度为主要控制指标,通过正交试验确定了SBS、SBR、HVA的最佳掺量。采用因素水平法与极差分析相结合,研究了3种改性剂对沥青60℃动力黏度的影响规律;采用软化点差法评价高黏度复合改性沥青的热储存稳定性;采用动态剪切流变仪测定高黏度改性沥青的60℃零剪切黏度和高温下的车辙因子来评价沥青的高温稳定性能;采用弯曲梁流变仪测定高黏度改性沥青在低温下的蠕变速率来评价沥青的低温抗裂性能;通过傅里叶变换红外光谱分析高黏度复合改性沥青的改性机理;采用扫描电子显微镜观察改性剂的微观改性效果。结果表明,以质量分数5%的SBS、质量分数2%的SBR和质量分数10%的HVA复合而成的高黏度改性沥青黏度高、高低温稳定性能强,且满足热储存稳定性要求;SBS、SBR、HVA与基质沥青共混,既存在物理变化,又有化学反应的发生。

浅部地层自由套管外二次置换固井水泥浆体系研究

胜利油田经过了二十多年的开发,早期的开发井油层套管水泥面以上的套管腐蚀破坏严重,严重干扰正常生产。为此,拟对浅部地层自由套管段进行二次固井,可在修复套管密封失效的同时防止套管进一步腐蚀。针对环空二次固井注浆施工工艺特点,结合浅部地层松软的特点,在明确浅部地层自由套管外二次固井性能需求的基础上,对水泥浆体系进行开发。通过对胶凝材料体系、低黏触变剂、降失水剂和缓凝剂的研选,构建出一种低密度-低黏度-强触变-长稠化时间的固井水泥浆体系,其配方为:40%G级油井水泥+30%粉煤灰+30%矿渣+(20%~25%)低黏触变剂L-TA+2.5%聚乙烯醇降失水剂+(0.16%~0.32%)氧化锌+1%分散剂+0.5%消泡剂,水固比为0.56,水泥浆密度低至1.5~1.6 g/cm^(3),黏度小于50 mPa·s,稠化时间大于15 h,平均静切力差值为17.885 N/m2、且触变具有可重复性,满足东部老区浅部地层自由套管外二次固井作业的要求。

TPS改性剂对高黏改性沥青流变性能稳定性的影响

为进一步量化高黏改性剂对高黏改性沥青性能的影响,本研究通过在基质沥青里添加不同剂量的TPS高黏改性剂来制备改性沥青,并对比不同改性沥青软化点、25℃针入度、5℃延度、60℃动力黏度等流变指标。研究表明TPS高黏改性剂掺量对沥青软化点、5℃延度和60℃动力黏度影响显著,三者均随掺量的增加而增加,针入度则与TPS高黏改性剂没有显著关系;TPS高黏改性剂掺量从8%增加到10%的过程中,高黏改性沥青的软化点、5℃延度和60℃动力黏度会显著提升;TPS高黏改性剂掺量达到10%后,改性沥青会出现明显的不稳定现象,三大指标和60℃动力黏度各平行试件之间的标准差会显著上升;不同类型改性剂对沥青黏聚黏结能力的提升效果不一样,合理选择改性剂能显著改善沥青的性能。另外试验结果还证明,提高剪切速率和剪切时长能在一定程度上降低实验室内制成的高掺量改性沥青的变异性和不稳定性。

非溶剂致相转化法PTFE/TPU复合膜制备与性能表征

以热塑性聚氨酯(TPU)为原料,N,N-二甲基乙酰胺(DMAc)为溶剂,乙酸和氯化锂(LiCl)为添加剂,聚四氟乙烯(PTFE)平板膜为基材,采用非溶剂致相转化法制备PTFE/TPU复合膜。考察了膜层厚度、凝胶浴组成、添加剂类别及其比例等条件对铸膜液黏度的影响,评测了膜表面和断面形貌结构、孔径分布、表层与基材剥离强度等膜特征指标。结果表明,与基膜c相比,复合膜的氮通量降低,膜层厚度为20μm时氮气通量越大;凝胶浴为24%DMAc时复合膜透气性最好,12%、48%DMAc时透气性差;乙酸做添加剂时复合膜表面光滑致密,而LiCl表面呈多孔结分布,但是当乙酸、LiCl添加剂比例相同时,加入乙酸的复合膜的透气性远比加入LiCl好;乙酸含量为0.7%时,PTFE/TPU复合膜的表面光滑致密,且透气性良好,平均孔径约为100 nm,0.7%乙酸的加入对铸膜液黏度及PTFE/TPU复合膜的剥离强度的影响较小。

不同类型高黏沥青及排水沥青混合料的性能发展规律

为了解决排水沥青混合料养生时间长的问题,分析了早强型高黏剂对高黏沥青及排水沥青混合料性能发展规律的影响。首先,根据不同养生时间下高黏沥青及排水沥青混合料的性能发展规律,明确了常规排水沥青混合料适宜的养生时间范围。其次,采用研发的早强型高黏剂分别制备了高黏沥青和排水沥青混合料,分析了养生时间对二者关键性能发展规律的影响。结果表明:与室内高速剪切法相比,拌制排水沥青混合料时高黏剂与沥青的融合效果较差,发育时间较长,在养生24~48 h后排水沥青混合料的性能方才趋于稳定;早强型高黏沥青的高温性能、疲劳性能在6~12 h较短时间内即趋于稳定;掺加早强型高黏剂显著提高了排水沥青混合料的早期强度,并且混合料的高温稳定性、低温抗裂性和水稳定性均有一定程度改善;采用早强型高黏剂可以加快排水沥青混合料的性能发展,将养生时间缩短至12 h以内。

湍流减阻剂聚α-烯烃的流变性能实验研究

针对成品油长输管道中聚合物减阻剂流动性能差、注入系统容易堵塞等问题,采用旋转流变仪、电子显微镜和动态光散射系统,从微观和宏观角度分析了悬浮颗粒尺寸形态、温度和剪切速率对3种不同组分的直链聚α-烯烃油溶性减阻剂流变性能的影响。实验结果表明:在-4—40℃温度区间内,FLOMX减阻剂悬浮颗粒直径为100—200μm,紧密均匀排列,相互作用力较强,在剪切速率分别为5,10,50,100 s-1的条件下,黏度变化率分别对应为262.2%,251.3%,216.1%,230.2%;减阻剂СНИТРЕН4110和СНИТРЕН2110的悬浮颗粒直径小,且黏度变化率较小,即减阻剂悬浮颗粒尺寸与其黏温性能呈负相关。基于以上研究结果,可知聚合物减阻剂最佳注入温度区间为25—40℃,且注入时应提高剪切速率(>30 s-1),以此提高成品油管道湍流减阻剂的注入效率。

蒸煮型聚丙烯流延膜芯层专用料的开发

根据市场主流牌号分析,确定蒸煮型聚丙烯流延膜芯层专用料的开发目标。筛选出芯层专用的球形无机纳米复合助剂C(添加量为0.04%),在茂名石化国产2代聚丙烯装置成功生产出蒸煮型流延膜芯层专用聚丙烯树脂PPR-F08M-S,并对产品物性进行分析和加工应用试验,结果表明:树脂黄色指数为-4.62,拉伸强度达到29.4 MPa,弯曲模量为791 MPa,薄膜雾度为0.82%,薄膜制品综合性能较好,与进口树脂性能相当。

高黏沥青用温拌剂的优选及其性能评价

该研究选取了不同类型的温拌剂制备高黏沥青,以软化点、25℃针入度、5℃延度、135℃布什黏度、60℃动力黏度确定度和热存储稳定性为评价指标,优选确定了合适的温拌剂类型及最佳掺量。结果表明,温拌剂的加入可有效降低135℃布什黏度,改善其施工和易性。同时随着温拌剂掺量的增加,高温性能、粘附力和热存储稳定性也随之提高,但其低温性能降低。综合考虑,确定温拌剂的种类为LQW-0400、最佳掺量为2.5%。

107生胶加水量与黏度之间的拟合计算

107胶生胶制备过程中加水量的多少能够对其黏度具有一定的控制能力,尤其是涉及到实际生产中的转产问题。利用实际生产中加水量与黏度数据进行拟合计算,寻找两者之间最为接近的数据模型,对107生胶转产具有指导意义。