新型复合技术用可粘接性氟聚合物

化工制药业、生物科技、食品加工和半导体行业等需要耐腐蚀、耐热和磨损，而且需要保持高纯度。另外由于环保、安全和健康方面需要保证有毒、有害液体或气体输送和储存时无渗透和泄漏；Kynar氟聚合物和Kynar ADX氟聚合物的涂装及复合技术可以提供比金属系统耐腐蚀和纯度更高的系统；也可以解决在塑料耐候、无渗透和泄漏、洁净场合的性能需求。Kynar ADX氟聚合物的涂装和复合技术可以和金属、廉价的聚合物、热塑性工程塑料粘接。这样可以充分发挥各种材质的特性和功能，制备各种形式的复合材料、部件和设备系统。     

1990年国内聚氨酯工业概况

简单评述了我国1990年聚氨酯生产、消费结构和新产品的研究状况。内容包括多元醇、异氰酸酯、助剂、软质和硬质泡沫、弹性体和合成革、涂料和复合涂料、粘结剂和密封剂、加工设备等。     

国外采脂和松香生产近况

一、采脂和松脂生产全世界的松脂产量每年约675,000吨。近年来,松脂产量最多的国家是中国,其次是苏联、葡萄牙、西班牙、墨西哥和印度。再其次是美国、法国、波兰、民主德国和希腊。保加利亚、匈牙利、南斯拉夫、土耳其、日本、新西兰和其它一些国家也进行松树采脂。从采脂生产的技术装备和对采脂进行科学研究的情况来看,美国占首位。     

第一、二、三产业范围重新划分

最近,国家统计局公布《三次产业划分规定》,重新划分了第一、第二、第三产业范围。第一产业是指农、林、牧、渔业。第二产业是指采矿业,制造业,电力、燃气及水的生产和供应业,建筑业。第三产业是指除第一、二产业以外的其他行业。第三产业包括:交通运输、仓储和邮政业,信息传输、计算机服务和软件业,批发和零售业,住宿和餐饮业,金融业,房地产业,租赁和商务服务业,科学研究、技术服务和地质勘查业,水利、环境和公共设施管理业,居民服务和其他服务业,教育、卫生、社会保障和社会福利业,文化、体育和娱乐业,公共管理和社会组织,国际组织。第一…     

浅议科研机构的创新

科研机构的创新对促进科技进步、加快经济发展和推动社会进步起着重要作用。探讨了科研机构的思维创新、科技创新、产业创新、体制创新、管理创新、人才创新和责任创新的理论和实际应用。指出科研机构要不断加大和提升思维、科技、产业、体制、管理、人才和责任的创新力度、能力和水平,走出一条适合自身发展的创新之路。     

吕氏聚氨酯泡沫填缝剂品质卓越

吕氏化工集团有限公司潜心研发并精心生产的单组分、快固化、多功能、广应用的聚氨酯泡沫填缝剂,具有较高的膨胀性和粘接性、优异的填缝性和封堵性、良好的保温性和隔热性、出色的抗震性和耐冲击性、较好的防水性和耐腐蚀性、优良的牢固性和耐老化性、可靠的环保性和安全性等特点。聚氨酯泡沫填缝剂是重点建筑工程在安装和保温方面应用较为理想的材料,能在各种结构部位对不同材料进行可靠的填充粘接与密封。适用于结构空缺、工程洞缺、所有裂缝等的填充,以及管道／电线出口、通风口、门窗周边、墙体裂缝等的密封。具有保温、隔热、防水、防潮、防腐、防尘、减震、降噪、绝缘、粘接、密封、固定等功能。     

主要国家和地区对脸彩和纹身贴的监管现状分析

分析了欧盟、美国、加拿大、澳大利亚、新西兰、东盟和中国化妆品法规中对化妆品的定义和对脸彩和纹身贴的监管情况。脸彩在欧盟、美国、加拿大、澳大利亚、新西兰和东盟按照化妆品进行监管,但中国无这方面的明确规定。从欧盟关于脸彩的召回案例和纹身贴常见问题回答来看,建议脸彩和纹身贴按照玩具化妆品的标准进行设计和生产。     

聚醚醚酮特性及应用

科技的发展对新材料有更高的性能要求。PEEK树脂的耐热水性和耐蒸汽性、自润滑性、耐高低温特性、制品尺寸稳定性、阻燃特性、电气绝缘性能和耐腐蚀特性等在航空航天、汽车制造、电子电气、医疗和食品加工、能源电力、石油勘探和开采和机械加工等领域有着广阔的应用前景和市场价值。     

全苏泥炭工业研究所VNIITP

全苏泥炭工业研究所按照苏联国家科学技术委员会的计划协调最重要的研究和发展。这个研究所的主要研究趋向是: ·研究泥炭和泥炭地的物理和化学性质,旨在决定泥炭地排水和准备开发的最佳技术方案。·为生产用于燃料、厩肥、堆肥和其他产物的泥炭,发展新的加工方法和机械。·进一步发展泥炭运输体系·发展生产种类繁多的泥炭产品(泥炭砖、混合物、营养土、吸附剂、饲料添加剂、生长刺激剂、泥炭钵、肥料和其他)的技术和生产线。·可行性研究和优化泥炭的机械和热机加工。     

上海化学试剂研究所

一、简介上海化学试剂研究所是从事各种化学试剂的研究和技术开发的专业性研究所。目前主要研制和生产高纯和有机试剂、临床诊断试剂、彩色显象管和电视机配套试剂、特种试剂以及其他精细化学品等。本所拥有先进的测试分析仪器,如气相和液相色谱仪、红外光谱仪、紫外分光和萤光光谱仪以及核磁共振仪等,纵向承担化工部、上海市科委、经委、化工局和试剂总厂下达的科研和测试分析任务,横向承接外单位的技术服务、技术咨询等委托业务。     

木材用聚氨酯胶黏剂的研究进展

聚氨酯胶黏剂由于具有无甲醛,施胶量少,胶接强度高等众多优点,使其在木材工业中的使用量逐步增加.但由于价格因素,聚氨酯胶黏剂在木材用胶黏剂中所占的比例仍然较小.研究聚氨酯胶黏剂与木材的胶接机理是从原理入手,掌握聚氨酯胶黏剂的胶接特点,用最少的原料来达到最好的胶接效果,以希望降低使用价格,扩大应用范围.简述聚氨酯胶黏剂的优点,开发和改性研究的基本思路,重点综述了国内外聚氨酯胶黏剂与木材胶接机理的研究进展.     

Bonding performance of melamine-urea-formaldehyde and phenol-resorcinol-formaldehyde adhesives in interior grade glulam

Wood moisture content (MC) affects the glued laminated beam (glulam) bonding strength. Selected adhesives were Phenol-Resorcinol-Formaldehyde (PRF) and Melamine-Urea-Formaldehyde (MUF) adhesives with 1, 1.5 and 2% (w/w) carboxymethyl cellulose (CMC) formic acid solutions. Douglas fir (pseudotsuga menziesii) from North America was used in the test. The bonding behavior of these adhesives with wood at 12 and 18% MC were investigated. The study focused on the effect of 18% MC on shear strength performance of MUF and PRF adhesives and optimizing the formula of CMC formic acid solution. Compressive shear strength of wood with MUF adhesive with 2% (w/w) formic acid solution at 12 and 18% MC stabilized at 10.6 and 10.0 MPa, respectively, which were 17 and 16% higher than that with PRF adhesive at the same condition. At 12–18% MC, MC had a little effect on bonding strength. However, 18% MC wood with PRF adhesive had 52.2% less initial strength increasing rate than that of 12% MC wood. 18% MC wood with MUF adhesives with 1, 1.5 and 2% (w/w) CMC formic acid solutions had 16.0, 15.5 and 27.0% less initial strength increasing rates than that of 12% MC wood, respectively. MUF adhesive using 2% CMC formic solution required the shortest press time at 12 and 18% MC about 1.6 and 2.7 h, respectively. The strength of PRF adhesive was significantly affected by wood MC and enough press time is essential for the proper bonding strength.     

Structure–property relationships in one‐component polyurethane adhesives for wood: Sensitivity to low moisture content

The causes of strength loss of wood joints and their consequent delamination from one‐component polyurethane adhesives used for bonding structural wood when used at a low moisture content was investigated by testing wood joint strength and elongation at rupture at different wood moisture contents and by ¹³C‐NMR spectroscopy and scanning electron microscopy of the hardened bond line. The combination of the relative proportion of the still‐reactive free ? NCO groups on the polyurethane, of the wise choice of degree of polymerization of the resin, and of a slower rate of reaction were the three parameters found to be important in overcoming the problem of poor or no bonding of wood at low to very low moisture contents from one‐component polyurethane adhesives. The results obtained indicated that one‐component polyurethane adhesives that had a combination of a higher proportion of still‐unreacted ? NCO groups, a lower degree of polymerization, and a slower reaction rate were capable of overcoming the problem of the high sensitivity of polyurethane gluing at low to very low wood moisture contents. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4181–4192, 2006     

Effect of thermal treatment of wood lumbers on their adhesive bond strength and durability

Wood used in outdoor applications needs to undergo either chemical or thermal treatment to improve its decay resistance. Thermal treatment permits to avoid the use of toxic chemicals, increases the dimensional stability and gives a dark color to the wood. However, this process deteriorates the mechanical properties of wood, i.e., the wood becomes more fragile and rigid. The chemical transformation of wood that takes place during the heat treatment changes the interaction between the wood surface and the adhesive. In this work, the interfacial bonding strength (the resistance to the shear stress by compression in parallel direction to the glued interface) and cyclic delamination (resistance to delamination during accelerated exposure) for different wood species and adhesives were tested in accordance with the ASTM D2559 standard. Four wood species: scott pine (Pinus sylvestris), aspen (Populus tremuloides), yellow poplar (Liriodendron tulipifera) and jack pine (Pinus banksiana) both treated and non-treated, and two structural adhesives, phenol resorcinol formaldehyde (PRF) and polyurethane (PUR), were used in the testing. Among the studied species, jack pine is found to be the easiest to bond, while aspen is found to be the most difficult. With the wood species and adhesives evaluated in this study, non-treated wood is found to provide a better bonding strength than the treated wood.     

Polyurethane wood adhesive from palm oil-based polyester polyol

Polyurethane (PU) adhesives for wood bonding were prepared from palm oil-based polyester polyol in a solventless condition that reduces the risk of volatile organic compounds to human health and the environment. The polyester polyol was synthesized from epoxidized palm olein prior to reacting with polymeric 4,4′-methylene diphenyl diisocyanate (pMDI) and toluene 2,4-diisocyanate (TDI) to produce wood-bonding PU adhesives. The effect of glycerol cross-linker, dibutyltin dilaurate catalyst and NCO/OH ratio on lap shear strength and pot life of the PU adhesives were studied. The green strength of the PU adhesives was achieved on day 4 for TDI-based adhesives and day 5 for pMDI-based adhesives. The newly formulated PU adhesives have superior chemical resistance in cold water, hot water, acidic medium and alkaline medium by only showing light deterioration (2–8%) in lap shear strength. The PU adhesives prepared from pMDI exhibited higher lap shear strength and thermal stability as compared to adhesives prepared from TDI adduct. Both adhesives have improved mechanical performance (two folds higher in lap shear strength) as compared to commercial wood bonding adhesives.     

Synthesis and properties of polyurethane wood adhesives derived from crude glycerol-based polyols

Crude glycerol, a waste stream of the biodiesel production process, is low-cost renewable feedstock for the production of chemicals and polymers. In this study, polyurethane (PU) adhesives were synthesized from crude glycerol-based polyols (CG-based polyols) for wood bonding applications. Effects of different variables, including hydroxyl values of CG-based polyols, chain extenders, and the molar ratio of NCO/OH on the properties of PU adhesives were investigated. The chemical structures of PU adhesives were characterized, and their thermal, mechanical, and chemical resistance properties were evaluated. The experimental results indicated that an increase of the NCO/OH molar ratio (1.3) substantially improved bonding strength by up to 38 MPa. Higher thermal stability and stronger chemical resistance to hot and cold water and to alkali and acid solutions were observed comparing to vegetable oil-based adhesives. However, the effect of the hydroxyl value of polyols on bonding strength was not significant. Additionally, bond strength of crude glycerol-based PU adhesives was comparable to that of some commercial PU wood adhesives. All these properties demonstrated the potential of CG for PU wood adhesive applications, particularly for fast-curing uses.     

Adhesive properties of water-washed cottonseed meal on four types of wood

The interest in natural product-based wood adhesives has been steadily increasing due to the environmental and sustainable concerns of petroleum-based adhesives. In this work, we reported our research on the utilization of water-washed cottonseed meal (WCM) as wood adhesives. The adhesive strength and water resistance of WCM adhesive preparations on poplar, Douglas fir, walnut, and white oak wood veneers were tested with press temperatures of 80, 100, and 130 °C. Our data indicated that raising the hot press temperature from 80 to 100–130 °C greatly increased the bonding strength and water resistance of the WCM adhesives. The general trend of the adhesive strength of WCM on the four wood species was Douglas fir > poplar ≈ white oak > walnut. The rough surface of Douglas fir with tipping features could enhance the mechanical interlocking between the wood fibers and adhesive slurry, contributing to the high adhesive strength. The dimensional swelling of the bonded wood pairs due to water soaking was in the order: thickness > width (i.e. perpendicular to the wood grain) > length (i.e. parallel to the wood grain). The greatest dimensional changes were observed in Douglas fir specimens. However, the highest decrease in adhesive strength by water soaking was with poplar wood specimens. These observations suggested that the wood dimensional changes were not dominant factors on water weakening the bonding strength of these wood pairs.     

Eco-economical polyurethane wood adhesives from cellulosic waste: Synthesis, characterization and adhesion study

This study reports the preparation of polyurethane adhesives using polyols obtained from cellulosic waste and detailed study on its adhesive strength in wood joints. Keeping in view the environmental hazards related to the huge paper-waste generation across the world, low-viscosity polyols have been prepared using magazine paper waste and vegetable oils with different physicochemical properties and were used to prepare two-component polyurethane adhesives for wood bonding. Polyurethane was analyzed by FTIR spectroscopy and TGA was used for the analysis of thermal properties. The adhesive strength was measured and compared with commercially available adhesives under different environmental conditions. The synthesized adhesive with NCO/OH ratio of 1.2 and curing time of 5 days was found to be superior to the commercial adhesives Fevicol™ and Araldite™ when compared simultaneously for the single-lap shear strength in different environmental conditions.     

豆基蛋白质胶粘剂改性及应用研究

为了降低豆基蛋白质胶粘剂的黏度、提高胶合板的耐沸水胶接强度和满足工业化的生产要求,对传统豆基蛋白质胶粘剂进行改性,并通过胶粘剂的黏度、pH值、凝胶时间、耐沸水胶接强度以及热分析结果等确定了改性剂的合理用量。然后以热压温度、热压时间、热压压力和涂胶量作为试验因素,以胶接强度作为考核指标,采用正交试验法优选出制备胶合板用改性豆基蛋白质胶粘剂的较佳工艺条件。结果表明:改性剂的合理用量(质量分数)是40%;胶合板的较佳热压工艺参数是热压温度140℃,热压时间5 min,热压压力1.2 MPa,双面涂胶量310 g/m2;在此较佳热压工艺条件下制备的胶合板,其耐沸水胶接强度较理想(为1.12 MPa),并且满足Ⅰ类胶合板的标准要求。     

Cure and performance of castor oil polyurethane adhesive

Aiming at the development of sustainable materials, in this study, a biobased wood polyurethane adhesive (PUA), derived from castor oil (CO), was synthetized and its properties were compared with a conventional wood adhesive. Different NCO/OH ratios have been used to assess its effect on the properties of the ensuing adhesives. FTIR, and DMA were used to monitor the extent of reaction and the glass transition temperature of the adhesive, respectively. In turn, the wood bonding properties of the PUA over time were assessed by lap shear using pine wood specimens. Is was observed that the lap shear strength increases with the increase of the R_NCO/OH up to R_NCO/OH = 2.50. Above this ratio, the adhesive performance decreases slightly, due to the rigidity of the PUA. Comparison with a conventional wood adhesive showed that CO derived adhesives presented similar strength properties but required less time to develop the ultimate bonding strength. The chemical and thermal stability of the most promising CO adhesive was also assessed. Despite of being sensitive to the chemical environment, the castor oil derived adhesives presented higher thermal stability than conventional wood adhesives.Finally, the cure process of CO derived adhesives was studied by differential scanning calorimetry and the Kissinger and Ozawa methods were used to determine the activation energy (Ea). The former afforded a value for Ea = 80.55 and the latter Ea = 87.07 kJ mol⁻¹. Moreover, it was observed that the activation energy is dependent on the degree of cure, increasing slightly up to 0.6 and decreasing significantly afterwards.