木粉聚醚的流变性研究

在新近开发成功的木粉聚氨酯新材料合成技术的基础上，对关键中间体木粉聚醚的流变性质、粘流温度效应进行研究。应用ＮＤＪ－１型旋转粘度计测得３０℃时木粉聚醚的流变数据和不同温度下的粘度数据。根据切变行为图和Ｍｅｔｚｎｅｒ方程，确定木粉聚醚为拟塑性流体，其表现粘度随剪切速串增大而明显降低，呈现剪切变稀的非牛顿流体特性。不同温度下木粉聚醚的粘度符合Ａｒｒｈｅｎｉｕｓ方程，据此求得木粉聚醚的流动活化能为５５．６ｋＪ／ｍｏｌ。     

紫外老化对沥青流变性能的影响

This paper simulated the ultraviolet aging process of asphalt and used dynamic mechanic analysis （DMA） method to evaluate the effect of ultraviolet aging on the asphalt theological properties. After having experienced ultravio- let aging, the low temperature performance of asphalt binder decreased significantly, with its complex modulus increased and phase angle decreased along with changing rheological properties as compared to the performance of original asphalt binder. The ultraviolet aging process would make asphalt binder more sensitive to brittle and fatigue failure. On the basis of the time-temperature superposition principle （TTSP）, the viscoelastic transition frequency （coT） is proposed to evaluate the effect of ultraviolet aging. It is found that with the increase in ultraviolet aging time, the cox moves to the lower frequency range gradually. Since the viscoelastic transition frequency is sensitive to the effect of aging, it can be used as an indicator of ultraviolet aging.     

粘弹性表面活性剂胶束体系及其流变特性

综述了粘弹性表面活性剂胶束体系及其流变特性，论题如下。①组成与微观结构，包括粘弹性表面活性剂压裂液简介。②流变学特性：胶束链长及其影响因素；胶束粘弹性动态特征；粘弹性胶束的松弛时间；粘弹性胶束的零剪切粘度；胶束压裂液的剪切流变行为。③微观结构和物化性能研究方法。图2表1参13。     

Prognostication of Wood Properties Alteration with Modification and Impregnation

The effects of wood roughness, modification and sanding on the water contact angle values of pine spruce and aspen wood surfaces were evaluated. Contact angle values set by time linear part extrapolation give increased values in comparison with ones obtained after water drop spreading on the surface. Water drop side-view contact angle along wood fiber directions is less influenced by surface roughness. Wood water activity （aw） can be used to ascertain available water content on surface.     

粘弹性表面活性剂溶液流变性及评价方法

介绍了粘弹性表面活性剂（VES）溶液的聚集特征和流变特性,综述了目前用于评价粘弹性流体流变性的几类方法及其仪器,包括小振幅振荡法,偏光显微镜观察法,环境扫描电镜观察法,核磁共振法等。     

耐温VES压裂液SCF的性能

长链脂肪酸在酸存在下与胺缩合再经季铵化,得到季铵盐型表面活性剂,引入无机和有机阴离子,得到粘弹性表面活性剂,溶于水中制成VES压裂液SCF。测定了体积分数4.0%的SCF压裂液170s-1下40～150℃的粘温曲线,温度升至150℃时粘度为68mPa·s,降温至90℃并维持130min后粘度为88mPa·s;在130℃剪切95min时粘度>80mPa·s,在150℃剪切45min时粘度～70mPa·s。在60℃、100～500s-1区间,上行和下行粘度～剪切速率曲线几乎重叠。少量水和互溶剂、少量原油、大量水可使SCF压裂液完全破胶。残渣率为176mg/L。砂比为10%时,粒径0.5～0.8mm石英砂在SCF压裂液中的悬浮率>90%。SCF压裂液对粘土的防膨率为80.5%。在原油与SCF体积比为1∶4和1∶1时,原油30℃粘度由1832mPa·s分别降至100和48.7mPa·s。图4表2参1。     

低取代度马铃薯醋酸酯淀粉合成工艺及性能研究

以马铃薯淀粉为原料．以醋酸酐为乙酰化试剂,氢氧化钠为催化剂对低取代度醋酸酯淀粉的合成工艺及性能进行了研究。考察了pH值反应温度、反应时间、氢氧化钠含量等因素对醋酸酯淀粉乙酰基含量的影响。通过正交实验得到了合成低取代度醋酸酯淀粉的最佳工艺条件：反应温度25℃,pH值8．5,淀粉(绝干)：醋酸酐质量比16：1,反应时间50min。影响因素由大到小的顺序依次为：反应pH、淀粉与醋酸酐质量比、反应时间、氢氧化钠含量、反应温度。实验结果表明,淀粉经乙酰化后,水溶性增大,糊化温度降低,糊液透明度提高。     

耐高温低伤害VES-HT01压裂液的性能

用具有超分子结构的阴离子型表面活性剂VES-HT01与6% KCl复配,得到新型耐高温低伤害的阴离子VES压裂液。压裂液性能评价结果表明,在100 s^-1剪切速率下,随温度升高,压裂液黏度先增加后降低,在100℃左右达到最高值180 mPa·s,150oC时的黏度为55 mPa·s。在140℃、170 s^-1下剪切60 min,黏度基本保持不变。黏弹性较好。25℃、100℃下陶粒在压裂液中的沉降速率分别为5、33 mm/min,悬砂性较好。在50℃、100℃下分别加入2%、1%柴油静置120 min后,压裂液黏度为3 mPa·s,无残渣,破胶液表面张力为23.5 mN/m。抗菌性良好。成本与常规瓜尔胶压裂液相当。     

羟丙基磺基甜菜碱压裂液体系性能研究

考察了羟丙基磺基甜菜碱VESBET-4浓度、pH值和无机盐的加入对体系黏度的影响,并评价了VES压裂液（2.5%表面活性剂+0.5%黏土稳定剂）的耐温抗剪切性能、携砂能力及破胶性能。结果表明:当转速达到250 r/min时,质量分数为2%的VESBET-4溶液的黏度可达到600mPa·s以上;该表面活性剂适于在中性及碱性条件下使用;且该表面活性剂与黏土稳定剂NH₄Cl、KCl具有良好的配伍性,无机盐的加入基本不影响体系的黏度。该压裂液体系具有良好的耐温耐剪切性能,在温度70℃、剪切速率170s^-1下的体系黏度仍高于50 mPa·s,60℃、170s^-1下剪切2h后的体系黏度仍高于85mPa·s。同时,单颗砾石的沉降速率为0.95 cm/h,砂比为30%时的砂子沉降速率为1.11cm/h,说明该体系具有良好的携砂造缝能力。使用模拟地层水可对该压裂液体系进行破胶,破胶时间在1 h内,破胶后体系黏度可降至4.27 mPa·s以下。图5表2参12     

芥酸酰胺丙基阳离子型黏弹表面活性剂的合成及其性能

以芥酸为原料,无溶剂条件下经两步法合成了N-(3-芥酸酰胺基)丙基-N-(3-羟基)丙基-N,N-二甲基溴化铵(产品Ⅰ)和N-(3-芥酸酰胺基)丙基-N-(3-羟基)丙基-N,N-二乙基溴化铵(产品Ⅱ)。利用FTIR、MS和两相滴定法分析了产品Ⅰ和Ⅱ的结构,并测定了活性物的含量。将产品Ⅰ和Ⅱ分别配制成黏弹性表面活性剂(VES)酸性体系,并测定体系的流变性能。表征结果显示,产品Ⅰ和Ⅱ中的活性物含量(w)分别为97%和96%;两种产品配制的VES酸性体系在170 s-1、100℃下剪切1 h后,体系黏度仍大于25 mPa·s,符合行业应用标准。产品Ⅰ和Ⅱ的分子结构中既含酰胺基和羟基,又含C21长烷基链,因此既增加了表面活性剂的亲水性,又改善了由于过长疏水链带来的疏水性。     

Characterizing the aging of asphaltic materials through the evolution of continuous relaxation spectrum

Abstract

Similar to other construction materials, asphaltic materials used for pavements are susceptible to environmental conditions. Subsequently, the environmental factors such as aging should be considered in the design process of flexible pavements. In this study, the possibility of the use of relaxation spectrum for viscoelastic materials to capture the effect of aging has been explored. Different types of asphalt binders and asphalt mixtures were tested and analyzed to ensure the validity of the results. The results indicate that through characterizing the evolution of spectrum using statistical parameters, the effect of aging on physical properties of asphaltic materials can be captured.     

含球孔缺陷聚乙烯管道热熔接头力学性能分析

针对聚乙烯管道的粘弹性材料属性,运用Ansys软件模拟和分析了含球孔缺陷的聚乙烯管道热熔接头的力学性能,借助Matlab编写循环程序预测失效寿命,并与聚乙烯管道正常服役年限进行比较。采用Prony级数模拟粘弹性材料属性,发现随着球孔尺寸的增大,聚乙烯管道的最大应力也增大,且聚乙烯管道的失效寿命缩短,当球孔尺寸超过一定值时,聚乙烯管道的寿命将无法满足要求。     

煤基均聚聚丙烯1100N性能研究

研究了煤基均聚聚丙烯1100N与对比试样的结晶性能、热氧稳定性能、相对分子质量及其分布、流变性能以及其他物理性能。研究结果表明,煤基均聚聚丙烯1100N的综合性能与同类产品相当,在加工应用领域可以替代石油基聚丙烯。     

PTFE颗粒对脲基润滑脂摩擦学特性的影响

采用微纳米聚四氟乙烯(PTFE)颗粒作为脲基润滑脂的添加剂。利用四球摩擦磨损试验机考察了微纳米PTFE颗粒添加剂的用量对润滑脂的摩擦学性能和极压性能的影响,用光学显微镜考察了磨痕表面的形貌,并测试了两种含微纳米PTFE颗粒试样的理化性能。结果表明,当微纳米PTFE颗粒添加量为1%时,润滑脂具有最佳的摩擦学性能。微纳米PTFE颗粒改善润滑脂摩擦学性能主要与其本身润滑性能较好有关。在摩擦中PTFE颗粒随润滑脂一起进入摩擦表面,在摩擦表面上形成PTFE颗粒与基体材料的复合层,阻止金属与金属的直接接触,减小了摩擦,降低了磨损。     

粘弹性表面活性剂压裂液VES-70工艺性能研究

粘弹性表面活性剂VES 70压裂液由复配表面活性剂VES 70和粘土稳定剂组成 ,其中VES 70为C16、C18烷基三甲基季铵盐与有机酸、异丙醇等的复配物。实验考察了VES 70胶束凝胶压裂液的应用性能。在 30℃下 ,VES 70溶液的表观粘度 (170s-1)随VES 70体积分数的增加而增大并趋于恒定值 :2 %溶液为 5 7mPa·s,4 %溶液为 175mPa·s,5 %溶液为 180mPa·s;4 %VES 70溶液的表现粘度随 pH值增大而增大 ,pH =1时不增粘 ,pH为 2～7时迅速增粘 ,pH为 9～ 11时增粘减慢。在 6 5℃、170s-1进行的 90min耐温剪切测试中 ,4 %VES 70溶液粘度降至 6 0mPa·s左右并保持稳定 ,这是VES压裂液的一个特点。在振荡频率为 6 .2 4rad/s时 ,随温度升高 (2 5～70℃ ) ,4 %VES 70压裂液的G′减少 ,G″增大 ,在 5 3℃时由G′ >G″变为G″ >G′ ,但G′值均 >2 .0Pa。 4 %VES 70压裂液以不同体积比与吉林原油混合 ,在 6 5℃破胶时间为 31.2～ 14 .1min ,破胶液粘度 5 .6～ 6 .1mPa·s ;与柴油等体积混合 ,6 5℃破胶时间 13.6min ,破胶液粘度 2 .7mPa·s ,表面张力 2 9.6mN/m ,界面张力 0 .33mN/m。在 6 5℃、3.5MPa下 4 %VES压裂液在低渗 (0 .0 80 7× 10 -3 μm2 )储层岩心中动态滤失系数为 7.5 2× 10 -4m/min0 .5,初滤失量为 2 .11× 10 -4     

天然气水合物的热物理性质

天然气水合物的热物理性质是研究和发展天然气水合物技术的基础。本文搜集和查阅了国内外关于天然气水合物热物理性质方面的最新研究成果,对天然气组成的单组分水合物的导热率,吸附热,分解热和比热等热物理性质进行了归纳和总结,明确了影响这些热物理性质的相关因素。针对目前的研究现状,提出了在已知水合物气体组成情况下,如何建立分析组分不同的天然气水合物的热物理性质的理论模型问题。     

纳米碳管对蠕虫状胶束流体流变特性的影响

采用流变学方法考察了纳米碳管种类、加量、矿化度及温度对CTAC NaSal蠕虫状胶束溶液流变性能的影响,并结合冷冻蚀刻电镜方法探讨了纳米碳管对黏弹性流体的改性机理。结果表明,纳米碳管与黏弹性胶束之间形成的复杂网络结构改善了体系的黏弹性。其中羟基含量高、长/径比大的多壁纳米碳管的增黏效果最好,纳米碳管的最优加量为04%,此时可使改性体系的零剪切黏度提高22倍。在低振荡频率下,纳米碳管对CTAC NaSal黏弹性胶束的增稠作用更明显,不仅松弛时间明显延长,体系的黏性和弹性也得到改善。纳米碳管还能提高CTAC NaSal黏弹性胶束的高温热稳定性,80℃下、剪切速率170 s-1时,纳米碳管改性CTAC NaSal黏弹性胶束溶液的黏度仍能保持在50 mPa·s以上。随着温度的升高,该体系的黏弹性逐渐降低,60℃以上呈黏性流体。     

Correlation Between Properties of Asphaltenes and Precipitation Conditions

Abstract

Asphaltenes from three crude oils were precipitated by using a pressurized system. Different conditions during the precipitation of asphaltenes were studied: pressure was varied between 15 and 45 kg/cm² and temperature between 40°C and 100°C. The effect of contact time and solvent-to-oil ratio was also studied in the range of 0.5–6 hr and 2:1 to 5:1 mL/g, respectively. Asphaltenes properties were analyzed as a function of pressure and temperature. It was found that in a deeper way temperature influences the asphaltenes properties than pressure in the range studied in this work. Asphaltenes properties were highly dependent on the nature of crude oil. Various correlations were developed and experimental and calculated asphaltenes contents and properties were in good agreement with absolute error less than 0.2%.     

Correlation Between Properties of Asphaltenes and Precipitation Conditions

Asphaltenes from three crude oils were precipitated by using a pressurized system. Different conditions during the precipitation of asphaltenes were studied: pressure was varied between 15 and 45 kg/cm² and temperature between 40°C and 100°C. The effect of contact time and solvent-to-oil ratio was also studied in the range of 0.5-6 hr and 2:1 to 5:1 mL/g, respectively. Asphaltenes properties were analyzed as a function of pressure and temperature. It was found that in a deeper way temperature influences the asphaltenes properties than pressure in the range studied in this work. Asphaltenes properties were highly dependent on the nature of crude oil. Various correlations were developed and experimental and calculated asphaltenes contents and properties were in good agreement with absolute error less than 0.2%.