胶乳法氯化天然橡胶溶胶和凝胶的分析

采用化学分析方法、高分辨裂解气相色谱－质谱、傅立叶红外光谱结合热分析技术对胶乳法氯化天然橡胶（CNR）中所含的溶胶和凝胶成分进行了分析。结果表明：胶乳法CNR中所含的凝胶成分主要为CNR分子的分子间交联物，具有与溶胶成分相似的氯化结构，氯含量较同等氯化程度的线性CNR稍低；胶乳法CNR中的凝胶成分的热稳定性及热氧稳定性较溶胶成分差，对胶乳法CNR的热稳定性及热氧稳定性会产生不利的影响。     

氯化天然橡胶的裂解色谱-质谱分析

用高分辨裂解气相色谱-质谱对由溶液法和胶乳法生产工艺制备的氯化天然橡胶（CNR）的结构进行了分析。结果表明,两种方法制备的CNR具有相同的主体结构,但精细结构有差异,胶乳法CNR的分子中含有少量手的羧基和羧基结构。CNR分子链上的环结构应为六元环。CNR的裂解特征产物是环己烷同系物。     

小颗粒“胶乳法”氯化天然橡胶穿透干燥试验

通过氯化天然橡胶(CNR)的穿透干燥试验,探讨风温、风速以及粒径对“胶乳法”CNR干燥速率的影响规律,结果表明,温度和风速对含水量的下降速率影响较大,而粒度对其影响较小。建立了穿透干燥方程,对实验数据进行了拟合,结果显示其吻合性较好。红外光谱分析以及物理性能测试结果表明,“胶乳法”CNR物料的干燥温度应控制在100℃以下。     

胶乳法氯化天然橡胶干燥历程中脱氯化氢反应动力学

新型工艺胶乳法氯化天然橡胶(CNR)产品在干燥过程中会有HCl脱出,其脱出量对CNR的制备、性能等有一定的影响。采用电导法可连续测定CNR在干燥历程中脱HCl量及速率,这是研究CNR在低温下热降解行为的有效方法。用改进工艺的"胶乳法"制备出湿的CNR,并在一定温度下通入氮气进行干燥,在此历程中会发生脱氯化氢反应,其反应过程可分为诱导期、恒速期和低速期。文中使用Friedman法分析该过程在恒速期、低速期的反应动力学参数,其脱氯化氢反应分别为0级反应、1级反应,活化能分别为26.65,36.79 kJ/mol。在80℃以下对产品进行加热(或干燥),虽有少量HCl脱出,但并不会对产品质量造成影响。所以干燥温度应以低于80℃为宜。     

膨润土的改性对水中氨氮和磷的去除效果研究

为了探索寻找到一种价格低廉、效果明显的降低水体氨氮和磷含量的方法,对具有资源丰富、价格便宜的膨润土灰进行了改性及吸附氨氮和磷的静态试验研究,结果表明：对膨润土进行酸、碱、盐和热改性后氨氮的吸附效果有所不同,顺序依次为：热〉碱〉盐〉酸;对膨润土进行酸、碱、盐和热改性后对磷的吸附效果也不同,顺序为：盐〉热〉酸〉碱。技术经济比较,热改性膨润土对氨氮的吸附容量大,而盐改性膨润土对磷的吸附容量大,在两种情况下膨润土是较理想的吸附剂。     

我国氯化橡胶的生产和发展概况

介绍了我国氯化橡胶(CNR)的生产现状和发展趋势。我国CNR主要采用传统溶液法(溶剂为四氯化碳)生产，胶乳法的年生产能力仅为数百吨。我国CNR生产存在工艺落后、产品粘度控制不准确、产品质量差、产品品种少、环境污染严重及产量远不能满足市场需求的问题。开发有自主知识产权的胶乳法和新型溶液法生产工艺、提高产品质量、扩大产品产量、减小环境污染是我国CNR行业的发展方向。     

基于流变学的浓缩胶乳改性沥青的黏弹特性

基于流变学理论研究了低氨浓缩天然胶乳（CNR）改性沥青的黏弹特性，使用动态剪切流变仪对不同CNR添加量的浓缩胶乳改性沥青进行温度扫描试验，从复数剪切模量（G*）、相位角（δ）、复数黏度（η*）及主曲线方面分析了温度及CNR添加量等因素对CNR改性沥青黏弹特性的影响。结果表明，随着温度的升高，CNR改性沥青弹性部分所占比例减小，而黏性部分所占比例增大；增加CNR的添加量可以提高CNR改性沥青的G*和η*，使δ明显降低，同时可以降低其温度敏感性，提高弹性、高温性能和抵抗剪切变形的能力。通过对比主曲线拟合参数参考温度的交叉频率和流变指数，进一步证明增加CNR的添加量可改善CNR改性沥青的黏弹特性，添加量越大，改善程度越高。此外，增加CNR的添加量使得CNR改性沥青从弹性到稳态流动的过程更加平缓，从而确保CNR改性沥青在中等加载时间和温度作用下不易发生脆性破坏。     

基于液气射流技术改进单宁酸氧化制备鞣花酸的工艺

针对鞣花酸在实际生产过程中耗时长、纯度低等问题，以单宁酸为基质采用液气射流氧化法制备鞣花酸，考察了金属离子、单宁酸浓度、反应温度和反应时间对鞣花酸得率及纯度的影响。进一步探究了溶剂法、结晶法、碱溶酸沉法、反溶剂法对鞣花酸纯度的影响，并通过高效液相色谱、红外光谱、紫外可见分光光谱和热重对鞣花酸高纯度的样品进行表征。结果表明，其制备的较优工艺条件为：2.5%单宁酸溶液中引入金属离子Na （即NaOH）调节反应液pH至8.5，反应温度20℃，反应时间6 h，该条件制备的鞣花酸经碱溶酸沉后产率为46.72%、纯度84.55%；选取甲醇溶剂洗涤法在65℃条件下处理1h，鞣花酸的纯度达98.13%，回收率为75.03%，提高了鞣花酸的热稳定性。液气射流氧化法与溶剂洗涤法相结合，大幅缩短制备鞣花酸的反应时间并明显提高其纯度，有望在工业生产中提高鞣花酸的生产效率并拓宽其在医药和化妆品领域的应用。     

树脂再生废液中和处理的计算与设计

对除盐系统酸、碱再生废液的中和处理的计算公式进行了推导，用理论分析和数理推导的方法．证明了除盐系统酸、碱再生废液混合后仍显酸性，并以此提出了再生废液中和处理新工艺，设计了新颖实用、符合环保要求的处理方案。     

川北柏垭区块大安寨一亚段储层敏感性评价

针对川北柏垭区块大安寨一亚段储层岩石孔隙结构差，属于致密储层的特点，对大一亚段的速敏性、水敏性、盐敏性、碱敏性和酸敏性进行了储层敏感性试验。结果表明，该段储层主要表现为弱速敏、中等偏强水敏、中等偏弱盐敏、无酸敏和中强碱敏。因此，在川北柏垭区块大安寨一亚段储层开发生产过程中应重点防治储层水敏性、盐敏性及碱敏性对储层带来的伤害，从而避免更大的经济损失。     

谷氨酸（钠）热解动力学的研究

采用热分析的方法研究了谷氨酸（钠）的热解过程。结果表明，在一定的温度下谷氨酸（钠）可脱水生成焦谷氨酸（钠），焦谷氨酸钠比焦谷氨酸稳定，升温速度和试样粒度对热解过程及动力学参数有一定的影响。     

Effects of dibutyltin dilaurate and epoxidized soya bean oil on the thermal stability of chlorinated natural rubber from latex

The effects of dibutyltin dilaurate (DBTL) and epoxidized soya bean oil (EBO) on the dehydrochlorination reaction of chlorinated natural rubber (CNR) from latex were studied by the measurement of the HCl evolving rate during the thermal degradation of CNR and by the determination of the amounts of cyclic conjugated dienes that formed on the CNR molecular chains. During the early stage of the thermal degradation of CNR at 150°C, HCl was eliminated, and the cyclic conjugated dienes formed on the CNR molecular chains. Under the effects of DBTL and EBO, the HCl evolving rates during the early stage of the thermal degradation of CNR were reduced, whereas the amounts of cyclic conjugated dienes formed on the CNR molecular chains were increased. Under the effects of mixtures from the compounding of DBTL with barium stearate or 2,2′‐methylene‐bis(4‐methyl‐6‐tert‐butyl‐phenol) as well as the compounding of EBO with 2,2′‐methylene‐bis(4‐methyl‐6‐tert‐butyl‐phenol), not only the HCl evolving rate from CNR but also the formation of cyclic conjugated dienes decreased, and this indicated that the compounded mixtures had synergistic functions against the thermal degradation of CNR. However, the mixture from the compounding of EBO with barium stearate had no synergistic effect on increasing the thermal stability of CNR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1986–1991, 2006     

Thermal degradations of chlorinated natural rubber from latex and chlorinated natural rubber from solution

The thermal degradations of chlorinated natural rubbers from latex (CNR‐L) and from solution (CNR‐S) under nitrogen atmosphere were studied with thermogravimetric analysis (TGA). The thermal degradations of CNR‐L and CNR‐S are one‐step reaction. The shapes of the thermogravimetric and derivative thermogravimetric curves are similar. The degradation temperatures of CNR‐L and CNR‐S increase linearly with the increment of heating rates. The heating rate hardly affects the thermal degradation rates of CNR‐L and CNR‐S at the various degradation stages. The thermal degradations of CNR‐S and CNR‐L are dehydrochlonation reactions. The reaction activation energy (E) of CNR, at the first stage, is around 100 kJ/mol. After that, E remains relatively steady (80–140 kJ/mol). At the last stage, E rises rapidly (130–270 kJ/mol). The variation tendency of frequency factor (A) is similar to that of E. As the initial degradation temperature T₀ of CNR‐L is 10.9°C lower than that of CNR‐S, the thermal stability of CNR‐S is better than that of CNR‐L, which may be caused by the difference of molecular structure between CNR‐L and CNR‐S, as FTIR results indicate that there are more ? OH, ? C?O and ? COO? groups in the CNR‐L molecular chains. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation and characterization of soluble polyaniline

Polyaniline, which is soluble in common organic solvents, has been synthesized through the oxidative chemical polymerization of aniline in the presence of benzene diazonium chloride salt in an aqueous HCl acid medium. The blue‐black polyaniline thus prepared exists in a lower oxidation state than emeraldine. An X‐ray photoelectron spectroscopy study has shown that the intrinsic oxidation state of the polymer is 0.38. An elemental analysis has shown that the fractional doping level or degree of oxidation of the blue‐black polyaniline is 0.26. The product is believed to consist of a lower number of imine nitrogens in comparison with the polyemeraldine base. This fact is also corroborated by the lower electrical conductivity of the polymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Effects of stearates on the thermal stability of chlorinated natural rubber from latex

The effects of stearates on the dehydrochlorination (DHC) reaction of chlorinated natural rubber (CNR) from latex were studied by the measurement of the HCl evolving rate during the early stage of the thermal degradation of CNR and by the determination of the amounts of cyclic conjugated dienes formed on the CNR molecular chains. During the early stage of the thermal degradation of CNR at 150°C, HCl was eliminated from the CNR molecular chains, and the cyclic conjugated dienes were formed on the CNR molecular chains. Under the effects of barium stearate, lead stearate, cadmium stearate, and calcium stearate, the HCl evolving rates of CNR were reduced, whereas the amounts of cyclic conjugated dienes that formed on the CNR molecular chains were increased. When zinc stearate was added, because of the formation of ZnCl₂, which was an active catalyst of the DHC reaction of CNR, both the HCl evolving rate from CNR and the formation of cyclic conjugated dienes were increased. The results indicate that the addition of stearates can reduce the thermal stability of CNR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1981–1985, 2006     

Study on preparation of chlorinated natural rubber from latex and its thermal stability

The effects of pH value of reaction system, reaction time, and reaction temperature on the chlorination reaction in the preparation of chlorinated natural rubber (CNR) from natural rubber latex were discussed. It has been found from the thermal analysis that the thermal degradation of CNR in nitrogen is a one-step reaction, and 30% carbonide with a stable structure remained at 360 to 700°C; whereas the thermo-oxidative degradation of CNR in air is a multistep reaction, and the thermal degradation ratio reaches to 100% at 560°C. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2863–2867, 1999     

Effect of chemical components of emulsion polymerization in aqueous media on Na-MMT nanostructure by XRD analysis

The effects of chemical ingredients of emulsion polymerization reaction consisting deionized water as media of polymerization, styrene and methylmethacrylate (MMA) as nonpolar and polar monomers respectively, potassium persulfate (KPS) as initiator, Dodecylbenzenesulfonic acid sodium salt (DBS-Na) and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) as conventional and reactive surfactants respectively, on nanostructural changes of pristine sodium Montmorillonite (Na-MMT) in aqueous media at ambient temperature and moderate stirring rate (150 rpm) was studied by X-ray diffraction (XRD) analysis. According to results, water can completely destroy the structural alignment of Na-MMT (in first stage with deflocculation and in second stage with defoliation), but it needs enough time (4 days). Addition of other chemical components in 48 h had different changes on water effect on nanostructure of Na-MMT. The interaction between AMPS and Na-MMT in aqueous media also was studied by thermal analysis (thermal gravimetery analysis and differential scanning calorimetery). It is illustrated that there are some strong interactions between AMPS and Na-MMT in water media which can lead to preparation of an end-tethered polymeric nanocomposite on Na-MMT layers through emulsion polymerization with this reactive surfactant.     

Influence of chemical polymerization conditions on the properties of polyaniline

The chemical polymerization of aniline in aqueous solutions was studied as a function of a wide variety of synthesis parameters, such as pH, relative concentration of reactants, polymerization temperature and time, etc. The polymer was synthesized using a number of different oxidizing agents and different protonic acids. It was found that the reaction yield was not sensitive to most variables. By contrast, the inherent viscosity of the polymer, measured in solutions in concentrated sulphuric acid, was strongly dependent on the synthesis parameters. Optimum reaction conditions are outlined for the chemical polymerization of aniline, for post-treatment with aqueous HCl solutions, and for compensation of the emeraldine salt into its base form. Under such conditions, high-quality polyaniline base was synthesized with an inherent viscosity (0.1% w/w polymer in sulphuric acid) as high as 2.32 dl g⁻¹.     

海藻酸钙纤维的结构与性能

研究了自制的海藻酸钙纤维的结构、热性能、燃烧性能以及对酸、碱和盐溶液的化学稳定性能。结果表明:海藻酸钙纤维的微观形态和粘胶纤维的相似,红外光谱结果证实了海藻酸钙纤维中"egg-box"结构的存在;海藻酸钙纤维的化学稳定性较差,随着处理液浓度和温度的升高,以及处理时间的延长,其稳定性越差;海藻酸钙纤维的热稳定性较好,极限氧指数为34.4,具有很好的阻燃性,属于难燃纤维。     

Thermal and chemical treatments of montmorillonite clay

Montmorillonite clay from a natural deposit was processed to remove impurities and later submitted for thermal and chemical treatments. The sample was first subjected to a thermal treatment at 400 °C, for 1 h, to remove organic components. The chemical treatment was conducted first by using an acid attack with nitric acid and sulfuric acid, then, adding sodium acetate in ethylene glycol clay dispersion, and finally the clay was dispersed in xylene with subsequent addition of silane, N-(b-aminoethyl)-g-aminopropyiltrimethylsilane. The combined thermal and chemical treatment was found to have a significant effect on the final chemical composition of the nanoclay. X-ray diffraction patterns suggested that the combined thermal and chemical treatment resulted in increased interplanar distances, thus favoring exfoliation of the clay lamellae, which was also confirmed by SEM images. Fourier transform infrared (FTIR) spectroscopy analysis suggested that the combined thermal and chemical treatment resulted in removal of water from the montmorillonite, without any modification or destruction of the clay structure. Thus, the combination of thermal and chemical treatments proposed in this work may be a promising approach to process montmorillonite intended for the production of advanced materials.