缔合法制备磷酸氢钙的探索研究

研究了以缔合剂ASAM和湿法磷酸为主要原料 ,选取适宜的钙原料 ,经缔合、置换、中和、过滤制备磷酸氢钙的工艺。磷酸氢钙产品达到国家饲料级标准 (GB82 4 7- 82 58- 87)     

橡胶用炭黑标准分类命名简介

1988年9月审定的“橡胶用炭黑标准分类命名系统”国家标准,等效采用了美国ASAM D1765—87。该标准是根据炭黑的基本性能,采用四符号分类命名法对橡胶用炭黑进行分级。分类系统中的第一个符号是字母,代表在含有     

对山毛榉ASAM蒸煮法和不同漂序漂白工艺的研究

用添加蒽醌和甲醇的碱性亚硫酸盐法(ASAM),可把山毛榉木片蒸煮到残余木素含量很低的程度,可制得高得率、高强度、漂白质量好的纸浆。纸浆漂白废水负荷很低,特别是使用O_3预漂时更是如此。山毛     

碳氮化钛的制备与应用

本文介绍了Ti（C，N）粉末的制备技术与其应用现状，分析了这些制备技术的工艺过程和工艺特点，Ti（C，N）具有广阔的工业应用前景，目前主要应用于金属陶瓷与耐磨涂层，另外含Ti（C，N）的复相陶瓷材料也具有许多优良性能。     

RTV导热硅橡胶组合物

一种RTV导热硅橡胶组合物，包含（A）两端具有可水解基团的有机聚硅氧烷，（B）在一端具有至少一个可水解基团的有机聚硅氧烷，（C）导热填料，和（D）具有可水解基团的有机硅化合物或其部分水解缩合物。该组合物即使填充大量导热填料（C），粘度也只经历最轻微的增加，具有很好的灌注、涂覆和密封性能，     

陶氏化学推出新型（苯乙烯／丁二烯）基共聚物

陶氏化学推出了新的（苯乙烯／丁二烯）基共聚物，在消费电子产品和家用电器零部件领域可作为（丙烯腈／丁二烯／苯乙烯）共聚物（ABS）的替代产品，不仅具有更好的成本优势，同时具有很高的冲击强度和良好光亮度等综合性能。     

PVP/(AA-co-AMPS)互穿网络水凝胶的制备及其电场响应性研究

通过两步溶液聚合的方法制备了由丙烯酸单体（AA）与2-丙烯酰胺-2-甲基丙磺酸（AMPS）的共聚物和聚乙烯基吡咯烷酮（PVP）形成的具有互穿网络状结构（IPN）的新型聚合物水凝胶。并研究了共聚单体配比、PVP和交联剂对水凝胶电场响应性及力学性能的影响。探索了凝胶在电场作用下的弯曲机理。实验结果表明：此种具有IPN结构的凝胶具有较好的电场响应性和力学强度。当n（AA）：n（AMPS）达到7：3，ω（PVP）=16％，ω，（交联剂）=0．05％时，水凝胶的综合性能达到最好。     

基于 ABS板上高铝粉定向用丙烯酸乳液的研究

以苯乙烯（ St）、甲基丙烯酸甲酯（MMA）为主单体，甲基丙烯酸羟乙酯（ HEMA）、双丙酮丙烯酰胺（ DAAM）和三羟甲基丙烷三丙烯酸酯（ TMPTA）为功能单体，正十二烷基硫醇（ NDM）为链转移试剂，利用粒子设计概念，制备了具有核壳结构的丙烯酸乳液，考察了 DAAM、HEMA、TMPTA和 NDM对铝粉定向性能的影响。结果表明：当 HEMA用量为 3%（以单体总质量计，下同）DAAM用量为 8%， TMPTA用量为 3%，NDM用量为 0. 6%时，制备的水性铝粉漆在 ABS板上具有优异的，排列效果，同时涂膜耐醇性好、硬度高、附着力好。     

SMA添加剂：改善材料的热性能、活性及相容性

作为一种具有高玻璃化转变温度（Tg）的无定形热塑性塑料，苯乙烯马来酸酐（SMA）共聚物提供了出色的力学性能和热性能（热变形温度（HDT）为120～150℃）。该材料还具有出色的热老化性、低吸湿性以及在精密成型中极低的收缩率，同时可实现出色的生产再现性。而该材料较低的线性热膨胀系数（CLTE）则有助于减少多组分材料体系中的热失配现象，     

专利文摘

薄膜卷绕用卷芯（1）具有：卷芯主体（2），具有筒的形状；和多个薄膜支撑部（4），从卷芯主体的外周面（3）突出。     

酸性助水溶剂脱除木质素机理分析

系统探讨了酸性助水溶剂对甲苯磺酸(p-toluenesulfonic acid,TSA)和马来酸(maleic acid,MA)分离桉木各组分的工艺过程,并对其中木质素脱除机理进行了研究。通过分析对比两种优化后的工艺发现：(1)两种酸性助水溶剂都可以高效脱除木质素,TSA木质素脱除率为67.94%,MA为65.14%;(2)在相同质量分数下,TSA的木质素脱除率比MA更高;(3)在温和条件下,TSA木质素的β-芳醚键含量比MA的高,随着反应条件的加剧,TSA和MA处理后木质素产品中β-芳醚键含量逐渐减少;(4)两种酸性助水溶剂处理后,纤维素保留率都较高,可保持90%以上;但是半纤维素的降解程度随着反应条件的加剧而增加;(5)酸性助水溶剂质量分数越高,在疏水表面的接触角越小,对木质素的助溶作用越明显,脱除木质素效率越高,溶液中木质素聚集体的粒径越小。综上所述,酸性助水溶剂对木质素的脱除基于润湿溶解、木质素芳醚键断裂、半纤维素降解等的综合作用。相关研究可为后续实现温和条件脱木质素工艺优化及机理提供参考。     

KINETICS OF AQUEOUS ETHYLENEDIAMINE-ETHANOL-ANTHRAQUINONE DELIGNIFICATION PROCESS

A new organosolv pulping method has been investigated. Delignification can be carried out by digesting the lignocellulosic material in an aqueous solution of ethylenediamine (EDA) and ethanol (EtOH) in combination with catalytic amounts of anthraquinone (AQ). This aqueous EDA-EtOH-AQ pulping is found to be highly selective in delignification and is flexible to softwoods. Bulk delignification was found to take place according to a pair of first-order mechanisms, like aqueous ethanol pulping. In the initial phase of delignification more than 50% lignin is removed, while the rest is extracted in the second slower step. The rate constants for each step are of the same order of magnitude and higher than those obtained in ethanol pulping. This indicated that overall delignification is faster when compared to aqueous ethanol pulping. The Arrhenius activation energy for the initial step was found to be 6.4 kcal/mole. The high selectivity in the detignification during the EDA-EtOH—AQ process is observed at all levels of delignification and shows at least an 18—20% increase in yield when compared with ethanol pulping.     

Organosolv delignification of white‐ and brown‐rotted Eucalyptus grandis hardwood

Sound (undecayed control) and fungally‐pretreated wood samples were submitted to organosolv delignification. The cooking liquor used was methanol/water (78:22 v/v) containing CaCl₂ and MgSO₄ each at a concentration of 25 mmol dm⁻³. The cooking process was performed at 180 °C for reaction times varying from 5 to 100 min. Despite some differences in the lignin removal pattern, pseudo‐first order kinetic models permitted a prediction of delignification rate constants for all experiments. All biodegraded samples provided higher delignification rate constants than the undecayed control (2.0 × 10⁻²min⁻¹ for the undecayed control and, for example, 14.2 × 10⁻²min⁻¹ for the sample decayed by Trametes versicolor for 2.5 months). Biodegraded samples also presented significantly increased xylan removal rates. The type of biodegradation affected the behavior of wood samples under organosolv pulping. The highest delignification and xylan removal rate constants were observed in the sample decayed by T versicolor for 2.5 months (17% weight loss). However, high delignification and xylan removal rate constants were also observed in the sample decayed by Punctularia artropurpurascens for only 0.5 months (1.2% weight loss). Data obtained from a single fungal species pretreatment or data from all fungal pretreatments indicated that there is no clear correlation between the delignification constants and the wood weight or component losses. This lack of correlation suggested that the structure of residual polymers in decayed wood affects the delignification process in the organosolv pulping more than the removal extent of each individual component. © 2000 Society of Chemical Industry     

Xylanase effects on pulp delignification

Xylanase effects on softwood pulp delignification were investigated experimentally and using mathematical models. The effect of xylanase molecular size on pulp delignification was investigated. As xylanase molecular weight decreased from 67 kDaltons to 20 kDaltons, lignin removal from pulp increased from 30 wt% to 48 wt%, respectively. The rate of xylanase-aided pulp delignification was studied using a batch system. The rate-data was fitted to a mathematical model of the batch system that enabled estimation of process parameters including xylanase and lignin effective diffusivities, lignin mass transport coefficient, and effective particle diameter for mass transport. Parameter values thus obtained were used to simulate the semi-batch delignification process, which predicted 84.6% of lignin available to UGA xylanase (MW=39,000 Daltons) would be removed in 2.5 h.     

Enhanced Delignification of Wheat Straw by the Combined Effect of Hydrothermal and Fungal Treatments

Delignification is the crucial step for the conversion of lignocelluloses to biofuel. In this work, wheat straw delignification was enhanced by a two-step process, comprising hydrothermal and fungal treatments. Wheat straw was exposed to hydrothermal treatment at subcritical temperatures and then subjected to fungal treatment. Lignocellulose hydrolysis rate was significantly higher during the hydrothermal treatment compared to the slower fungal delignification. However, by-products of lignin degradation via hydrothermal treatment were re-deposited on the cellulose fibers as the substrate was cooled to room temperature. It is shown that post-treatment fungi can enhance delignification by degradation of the residual lignin by-products. The effect of fungal delignification of hydrothermally treated substrate was a function of temperature of the hydrothermal process. Compared to the hydrothermal treatment, the novel combined approach, proposed in this study, resulted in two-fold higher delignification and promises to be an effective method for delignified substrate preparation for conversion to biofuel.     

XYLANASE EFFECTS ON PULP DELIGNIFICATION

Xylanase effects on softwood pulp delignification were investigated experimentally and using mathematical models. The effect of xylanase molecular size on pulp delignification was investigated. As xylanase molecular weight decreased from 67 kDaltons to 20 kDaltons, lignin removal from pulp increased from 30 wt% to 48 wt%, respectively. The rate of xylanase-aided pulp delignification was studied using a batch system. The rate-data was fitted to a mathematical model of the batch system that enabled estimation of process parameters including xylanase and lignin effective diffusivities, lignin mass transport coefficient, and effective particle diameter for mass transport. Parameter values thus obtained were used to simulate the semi-batch delignification process, which predicted 84.6% of lignin available to UGA xylanase (MW=39,000 Daltons) would be removed in 2.5 h.     

稻草木素生物降解的研究

介绍了我们最近对稻草木素生物降解研究进展。通过诱变选育分离出高降解木素的优良菌株,10天内脱木素率高达59%,明显地缩短了生物作用周期;利用电子显微镜技术,详细揭示白腐菌生物降解草类植物的微观过程和稻草组织内部以及纤维细胞壁的微观结构的变化,同时,发现所选育的菌种具有:(1)优先降解纤维胞间层,致使纤维能保持完整地分离;(2)没有发生纤维细胞壁变薄破坏的现象;(3)生物作用初期就能分解除去不利于造纸的薄壁细胞;(4)能选择性降解纤维次生壁上的木素,微细纤维结构不被破坏而裸露出来等非常可贵的优良特性。这些特性十分有利于生物制浆造纸。系统分析和研究了生物脱木素过程及一些重要生理条件对脱木素的影响规律。发现生物脱木素过程可分为三个阶段。不同阶段生理条件对脱木素的影响不同。通氧培养、添加营养氮源或碳源及控制底物的湿含量能促进生物脱木素作用。为了解稻草木素生物降解规律,利用核磁共振技术定量及定性分析比较生物作用前后木素的结构特征。结果表明木素大分子的生物降解主要是氧化反应,在菌的作用下,木素结构中 C_γ被氧化、C_α—C_β键、C_β—C_γ,键以及芳香环被氧化断裂。其降解顺序为:以酯键连结的对香豆酸为主体的对羟苯基单元,愈疮木基单元和紫丁香基单元。菌优先作用于纤维细胞间层的结论与电子显微镜观察结果一致。上述特征和规律显示白腐菌 P.conchatus 对发展草类生物制浆及其他脱木素工艺均具有巨大潜在应用优势。     

氧脱木素效率的改善途径

氧脱木素被认为是除了硫酸盐蒸煮脱木素外,成本最低且最简单的脱木素方法,所以氧漂可以把制浆与漂白结合起来。且氧脱木素技术具有环境污染小、漂后纸浆质量高等优点,现已成为ECF和TCF漂白的主体工艺。氧脱木素是以分子氧为漂白剂,酚型木质素与O2反应从而消除侧链,打开苯环,脱甲基化而被氧化降解。该过程受到用碱量、反应温度、时间、氧压、浆浓等许多工艺参数的影响。为改善氧脱木素效果,研究者提出了多种方法,如两段氧脱木素、助剂强化氧脱木素及氧脱木素前预处理等。氧脱木素在我国的应用前景是很广阔的,而且环境保护法规的日益严格对实施氧脱木素技术也十分有利,因此对于氧脱木素的研究还需继续。     

氧脱木质素对稻草SFP浆性能的影响

亚硫酸盐―甲醛―蒽醌(SFP-AQ)法是适合于草类原料的一种制浆方法。文章研究了氧脱木质素对稻草SFP浆的卡伯值、白度、粘度及强度性能的影响。结果表明,较高的用碱量有助于残余木质素的脱除,在合适的工艺条件下,稻草SFP浆单段氧脱木质素的脱木质素率可达50%以上。在氧脱木质素用碱量3.5%、氧压0.4 MPa、温度110℃、时间60 min或90 min的条件下,稻草SFP浆的卡伯值较低、白度较高,而同时具有良好的粘度和强度性能。     

The Kinetics of the Sulphate Pulping of Gmelina arborea From Ghana

Investigations concerning the behaviour of Gmelina arborea wood growing in a plantation in Ghana by the Kraft delignification process were carried out in the St. Petersburg (formerly Leningrad) Academy of Forest Technology and Engineering in the Commonwealth of Independent States (Russia).

The basic kinetic data such as the rate constant, order of reaction, temperature dependence and the energy of activation were calculated. The kinetic data obtained indicate that the dielignification of G. arborea is by a process similar to that of diffusion as occurs during chemical reactions. Consequently, the delignification process at temperature which was carried out at selected cooking conditions is not solely controlled by kinetic processes.