胶合板用尿素改性酚醛树脂胶合性能的研究

制备了不同尿素用量的系列尿素改性酚醛（PUF）树脂体系（当尿素用量为苯酚质量的0、25%、43%、66%时分别记为PF、PUF-1、PUF-2、PUF-3）,并将其用于制备胶合板,研究树脂在胶合板加工过程中的变化。结果表明：PUF-3树脂与桉木和杨木的接触角为79.6°和81.1°,小于PF树脂的,PUF对桉木相容性比杨木优良,PF树脂则相反;对4种树脂进行DSC分析显示,PF、PUF-1、PUF-2、PUF-3固化速率最大温度分别为146.8、171.4、171.8和171.8℃;PUF-3和面粉共混体系的流变行为显示该共混体系110℃开始发生固化反应,（130±5）℃为较合适的热压温度;对热压前后PF和PUF-3进行热重分析,结果发现PUF的耐高温性能优于PF,热压后形成的结构耐热性也更好;4种树脂压制的胶合板性能达到E₀级,甲醛释放量均小于0.5mg/L,胶合强度分别为1.42、1.11、0.98和0.92MPa。     

苯酚-尿素-甲醛共缩聚树脂基泡沫材料的制备和性能

以木材工业用苯酚-尿素-甲醛(PUF)共缩聚树脂为原料制备出了PUF发泡材料,采用扫描电镜和元素分析等手段对PUF泡沫材料的结构和化学特性进行分析,进而研究了制备工艺,尤其是发泡剂用量、固化剂用量以及发泡温度三个主要的工艺参数对泡沫材料表观密度的影响,制备出了密度在0.035~0.12 g/cm3范围内的PUF泡沫材料。最后探讨了材料的表观密度和抗压强度之间的关系,即PUF泡沫材料的抗压强度随着密度的增大而增大,可以作为承重用防火保温材料。     

无溶剂浸胶制备玻纤布半固化片工艺研究

以双酚A型环氧树脂和邻甲酚醛环氧树脂复配作为基体树脂,双氰胺为固化剂,咪唑2E4MZ为促进剂,无溶剂法浸胶制备玻纤布半固化片。探讨了基体树脂和促进剂对半固化制备工艺的影响,着重研究了无溶剂法玻纤布浸胶工艺和半固化片制备工艺。研究结果表明:当w(双酚A型环氧)=15%、w(酚醛环氧704)=75%、w(双氰胺)=10%(相对于浸胶总质量而言),w(2E4MZ)=6%(相对于双氰胺质量而言),涂布机温度为110℃下浸胶可达到完全浸润玻纤布;半固化工艺为130℃/9 min时,可得到具有高的分解温度(360℃)、玻璃化转变温度(165℃),耐浸焊性时间长(242 s),击穿电压(46 kV)、介电常数(4.35)、剥离强度(1.45 N/mm)优异的玻纤布半固化片覆铜板。     

《粘接》杂志“2011年度十佳优秀论文”名单

1、碱催化2步法制备SiO2/环氧树脂杂化材料的研究(第1期)党婧(中航工业第一飞机设计研究院)2、E0级室外型胶合板用PUF树脂胶的研制(第2期)赵临五1,王春鹏1,庄晓伟2,穆有炳1,施娟娟1,张伟1,石建军3,俞阳3,储富祥     

三甲胺修饰戊二醛交联壳聚糖树脂的制备及其吸附性能

用水相均匀交联法制备戊二醛交联壳聚糖树脂 ,以三聚氯氰为活化剂 ,合成了三甲胺修饰戊二醛交联壳聚糖树脂 ,研究了该树脂的红外光谱特征及吸附性能。该树脂对铜 (Ⅱ )和牛血清白蛋白 (BSA)的吸附容量分别为 37mg/g和 460mg/g(以折合干重计 ) ,其吸附行为符合Freundlich等温吸附模型。该树脂制备工艺简单 ,可作为蛋白质分离纯化的吸附剂     

涂料用水溶性光敏树脂的制备及性能

以含环氧基的光敏性丙烯酸酚醛环氧树脂为原料合成了一种可以在 1 %的碳酸钠溶液中溶解的光敏性酚醛环氧树脂 (AAFEE) ,研究了该树脂的合成条件及工艺。发现当反应温度为 95°C、选用溴化季铵盐作为反应的催化剂、反应时间为 3h可获得在低浓度碱溶液中溶解的涂料用树脂(AAFEE)。当树脂中 n(环氧基 )∶n(羟基 )∶n(琥珀酸酐 ) =3∶ 7∶ 6、3∶ 7∶ 5时 ,以此树脂制备的涂料具有优良的力学性能。光敏实验证明 ,AAFEE树脂中的碳碳双键具有较高的光学反应活性 ,光照 1 5s后转化率可达 60 %以上。     

聚醚酰亚胺对共聚双马来酰亚胺树脂的增韧作用

采用二烯丙基双酚A、烯丙基酚醛改性4,4'-二氨基二苯甲烷双马来酰亚胺共聚制备了一类新型的双马来酰亚胺树脂(简称ABD)。以ABD为基体,选用热塑性树脂聚醚酰亚胺(PEI)为增韧剂,采用共混法制备了共聚双马来酰亚胺/聚醚酰亚胺(PEI)树脂体系。采用DSC和流变仪对ABD树脂的固化行为进行了研究,结果表明,该树脂粘度较低,室温下为液态,树脂的冲击强度为8.99 kJ/m2。通过DMA、TGA和扫描电镜对PEI加入量对树脂热性能和微观形貌的影响表明,添加质量分数为15%聚醚酰亚胺时,树脂冲击强度达到16.9 kJ/m2,比基体树脂提高了88%。     

酚醛树脂及其涂料

0005021反应型酚醛涂料:EP945497t欧洲专利公开英]/芬兰:Dyooresi:、oy(Lippo,‘e,,,Juha等)一1999.9,29尸10页、一Fll998/672(1998.3.25):IPC C09D 161/06 该涂料是一种用碱性树脂组合物浸涂处理的胶结材料,所用组合物含有甲醛/苯酚(RP)摩尔比为l一3的甲阶酚醛树脂,占液态树脂计算量0.4%一5.0%的醋、醋的衍生物或其混合物,并且树脂组合物的碱度比液体树脂计斧最过量l%。该发明还涉及酚醛涂料的制备方法以及该涂料在各种板材制品表面的涂装应用、在板材制品和/或金属板表面粘合其他涂层、胶合板和纤维薄板的应用、作为其他涂层的底涂…     

海外橡胶加工专利精选

<正>一、轮胎具有极好耐磨性和低生热的充气轮胎Jpn.Kokai Tokkyo Koho JP 2012162603该轮胎由橡胶、酚醛清漆型间苯二酚树脂、可熔型酚醛树脂组成。将273g碎状的C石油树脂(ECR 1102)分散在HO中,与3636g 20%天然橡胶胶乳(含NH)混合,通过HCOH凝聚、粉碎和干燥,制备树脂填充的天然橡胶(37.5份树脂/100份天然橡胶)。然后与炭黑(Seast KH)50份、酚醛清漆型间苯二酚-HCHO共聚物/可熔型酚醛树脂30/70的混合物14份、硬脂酸2份、抗氧剂1份、氧化锌4份、硫化促     

环氧豆油/酚醛交联树脂的制备和抗吸水机理研究

通过苯酚羟基醚化和环氧豆油(ESO)扩链聚合制备了环氧豆油/酚醛(PR)交联树脂,采用扫描电子显微镜和热分析分别研究了醚化和扩链对改性酚醛树脂微观形貌及抗吸水性的影响.ESO扩链聚合物与酚醛树脂不相容,通过醚化反应可改善相容性并接枝形成软硬链段交联网络.ESO与酚醛交联聚合能够增强树脂的抗吸水性,由该交联树脂制得的纸层...     

13C‐NMR study on the structure of phenol‐urea‐formaldehyde resins prepared by methylolureas and phenol

Phenol‐urea‐formaldehyde (PUF) resins were synthesized by reacting mixture of methylolureas (MMU), phenol, and formaldehyde. The structure of PUF cocondensed resins at different stages of reaction were analyzed by liquid ¹³C nuclear magnetic resonance (NMR) spectroscopy. The liquid ¹³C‐NMR analysis indicated that methylolureas had the dominant content in MMU with the reaction between urea and formaldehyde under the alkaline condition. The PUF cocondensed resins had no free formaldehyde. methylolureas were well incorporated into the cocondensed resins by reacting with phenolic units to form cocondensed methylene bridges. The second formaldehyde influenced the further reaction and the structure of the PUF resins. The resins with the prepared method of PUFB possessed relatively high degree of polymerization and low proportion of unreacted methylol groups. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Phenol–urea–formaldehyde resin co-polymer synthesis and its influence on Elaeis palm trunk plywood mechanical performance evaluated by 13C NMR and MALDI-TOF mass spectrometry

This study evaluated a new method of producing phenol–urea–formaldehyde (PUF) adhesives formulated differently under actual “in-situ” resin synthesis conditions. This was carried out by co-polymerizing urea formaldehyde (UF) resin with phenol–formaldehyde resin in the core layer of low molecular weight (LMW) phenol–formaldehyde (PF) resin treated Elaeis palm trunk veneers during the gluing process of Elaeis palm plywood. Matrix assisted laser desorption Ionization time of flight (MALDI-TOF) mass spectrometry (MS) illustrated and confirmed a series number of the phenol–urea co-condensates repeating unit in the prepared PUF resins which corroborated well with its mechanical properties (modulus of elasticity and modulus of rupture), bonding quality (dry test and weather boil proof or WBP test) and physical properties. A series of PF, UF and PUF resins oligomers forming repeating units up to 1833 Da were identified. Besides that, the solid state ¹³Carbon nuclear magnetic resonance (NMR) interpretation identified that the signal at 44–45 ppm and 54–55 ppm corresponding to methylene bridges were co-condensated in between phenol and urea in the PUF resin system. The ¹³C NMR investigation showed that the synthesis process of PUF resin contained no free formaldehyde elements. Furthermore, the proportion of urea and methylolureas in the mixture to synthesis PUF resin were sufficient and incorporated well into the formulation by reacting with LMWPF units to form co-condensed methylene bridges. This study showed a new and useful method to synthesize PUF resin during the gluing process of manufactured Elaeis palm plywood which can also enhance the performance of Elaeis palm plywood panels for structural instead of utility grade applications.     

Synthesis–structure–performance relationship of cocondensed phenol–urea–formaldehyde resins by MALDI‐ToF and 13C NMR

Matrix assisted laser desorption ionization time of flight (MALDI‐ToF) mass spectrometry has consistently confirmed on a number of PUF resins that phenol–urea cocondensates exist in phenol–urea–formaldehyde (PUF) resins. A noticeable proportion of methylene‐linked phenol to urea cocondensates were detected in all the PUF resins tried, alongside methylene bridges connecting phenol to phenol and urea to urea. The PUF, PF, and UF oligomers formed were identified. Variations of the PUF preparation procedure did always yield a certain proportion of the mixed phenol to urea cocondensates. Their relative proportion was determined and related the synthesis procedure used. Comparison of the MALDI‐ToF results with a ¹³C NMR investigation showed that in a real PUF resin in which phenol to urea cocondensates were identified the methylene bridge NMR signal at 44 ppm, characteristic of phenol to urea unsubstituted model compound cocondensates, does not appear at all. This confirmed that this peak cannot be taken as an indication of the existence of phenol and urea condensation under actual resin preparation conditions. The peak indicating cocondensation in PUF resins in which the phenolic nuclei and urea are substituted appears instead at 54.7–55.0 ppm. Thermomechanical analysis has again confirmed that the resin gel times greatly accelerates with increasing urea molar content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Fast advancement and hardening acceleration of low‐condensation alkaline PF resins by esters and copolymerized urea

Low‐condensation phenol‐formaldehyde (PF) resins coreacted under alkaline conditions with up to 42% molar urea on phenol during resin preparation yielded PUF resins capable of faster hardening times than equivalent pure PF resins prepared under identical conditions and presented better performance than the latter. The water resistance of the PUF resins prepared seemed comparable to pure PF resins when used as adhesives for wood particleboard. Part of the urea was found by ¹³C‐NMR to be copolymerized to yield the alkaline PUF resin; whereas, especially at the higher levels of urea addition, unreacted urea was still present in the resin. Increase of the initial formaldehyde to phenol molar ratio decreased considerably the proportion of unreacted urea and increased the proportion of PUF resin. A coreaction scheme of phenolic and aminoplastic methylol groups with reactive phenol and urea sites based on previous model compounds work has been proposed, copolymerized urea functioning as a prebranching molecule in the forming, hardened resin network. The PUF resins prepared were capable of further noticeable curing acceleration by addition of ester accelerators; namely, glycerol triacetate (triacetin), to reach gel times as fast as those characteristic of catalyzed aminoplastic resins, but at wet strength values characteristic of exterior PF resins. Synergy between the relative amounts of copolymerized urea and ester accelerator was very noticeable at the lower levels of the two parameters, but this effect decreased in intensity toward the higher percentages of urea and triacetin. ¹³C‐NMR assignements of the relevant peaks of the PUF resins are reported and compared with what has been reported in the literature for mixed, coreacted model compounds and pure PF and urea‐formaldehyde (UF) resins. The relative performance of the different PUF resins prepared was checked under different conditions by thermomechanical analysis (TMA) and by preparation of wood particleboard, and the capability of the accelerated PUF resins to achieve press times as fast as those of aminoplastic (UF and others) resins was confirmed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 359–378, 1999     

Characterization of phenol–urea–formaldehyde resin by inline FTIR spectroscopy

Phenol–urea–formaldehyde (PUF) resins were synthesized by a two‐step polymerization process. The first step was the synthesis of 2,4,6‐trimethylolphenol (TMeP) from phenol and formaldehyde, under alkaline conditions. In the second step PUF resins were synthesized by the reaction of TMeP with urea, under acidic and alkaline conditions. The influence of temperature on the synthesis of TMeP was investigated. The molar ratio between TMeP and urea was varied to study the composition effect on the second step of the PUF synthesis and final product properties. Synthesis of TMeP and PUF resins were monitored by inline FTIR‐ATR system. Analytical methods, such as differential scanning calorimetry, nuclear magnetic resonance, thermogravimetric analysis, and infrared spectroscopy were used for characterization of TMeP and PUF resins. Obtained PUF resins were cured and tested on flexural strength. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Influence of the synthesis conditions on the curing behavior of phenol–urea–formaldehyde resol resins

The curing behavior of synthesized phenol–urea–formaldehyde (PUF) resol resins with various formaldehyde/urea/phenol ratios was studied with differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The results indicated that the synthesis parameters, including the urea content, formaldehyde/phenol ratio, and pH value, had a combined effect on the curing behavior. The pH value played an important role in affecting the shape of the DSC curing curves, the activation energy, and the reaction rate constant. Depending on the pH value, one or two peaks could appear in the DSC curve. The activation energy was lower when pH was below 11. The reaction rate constant increased with an increase in the pH value at both low and high temperatures. The urea content and formaldehyde/phenol ratio had no significant influence on the activation energy and rate constant. DMA showed that both the gel point and tan δ peak temperature (T_tanδ) had the lowest values in the mid‐pH range for the PUF resins. A different trend was observed for the phenol–formaldehyde resin without the urea component. Instead, the gel point and T_tanδ decreased monotonically with an increase in the pH value. For the PUF resins, a high urea content or a low formaldehyde/phenol ratio resulted in a high gel point. The effect of the urea content on T_tanδ was bigger than that on the gel point because of the reversible reaction associated with the urea component. Too much formaldehyde could lead to more reversible reactions and a higher T_tanδ value. The effects of the synthesis conditions on the rigidity of the cured network were complex for the PUF resins. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1368–1375, 2005     

Chemical Structure and Curing Behavior of Phenol–Urea–Formaldehyde Cocondensed Resins of High Urea Content

Phenol–urea–formaldehyde cocondensed (PUF) resins of high urea content were prepared by adding different forms of urea to the reaction system. The structure, curing behavior, and water resistance of the PUF resins were investigated, and their relations were also discussed by liquid ¹³C nuclear magnetic resonance (NMR) and different scanning calorimetry (DSC). The liquid ¹³C-NMR analysis showed that urea added in the form of methylolureas was well incorporated into the cocondensed resins by reacting with phenolic methylols to form cocondensed methylene bridges, and that the PUF resins had no free formaldehyde with any form. Unreacted urea and low molecule monosubstituted urea of PUF resins play a dominant role in the curing behavior and water resistance of resins. The peak temperature, curing time, and curing enthalpy (ΔH) value correspondingly increased, however, the water resistance of PUF resins decreased when urea content in PUF resins increased. The PUF cocondensed resin with up to 89.4 % (W _U/W _P) urea has relatively low cost, and moreover can pass the requirements of China Industry Standard for the exterior grade of structural plywood after 4-h cyclic boiling test.     

Properties of phenol‐formaldehyde resins prepared from phenol‐liquefied lignin

In this study, alkaline lignin (AL), dealkaline lignin (DAL), and lignin sulfonate (SL) were liquefied in phenol with sulfuric acid (H₂SO₄) or hydrochloric acid (HCl) as the catalyst. The phenol‐liquefied lignins were used as raw materials to prepare resol‐type phenol‐formaldehyde resins (PF) by reacting with formalin under alkaline conditions. The results show that phenol‐liquefied lignin‐based PF resins had shorter gel time at 135°C and had lower exothermic peak temperature during DSC heat‐scanning than that of normal PF resin. The thermo‐degradation of cured phenol‐liquefied lignin‐based PF resins was divided into four temperature regions, similar to the normal PF resin. When phenol‐liquefied lignin‐based PF resins were used for manufacturing plywood, most of them had the dry, warm water soaked, and repetitive boiling water soaked bonding strength fitting in the request of CNS 1349 standard for Type 1 plywood. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Phenolic resol resin adhesives prepared from alkali-catalyzed liquefied phenolated wood and used to bond hardwood

Wood-based resol resins were prepared from both water- and sodium hydroxide (NaOH)-catalyzed liquefied phenolated wood. The effects of various reaction parameters, e.g. the concentrations of phenol and formaldehyde, temperature, and time, on the extent of yield, free phenol content, molecular weight as well as the gluability of the resol resins have been evaluated. As far as the yield, free phenol content, and molecular weight are concerned, the optimum conditions of resol resin preparation were found to be a phenol : wood weight ratio of 4 : 6, a formaldehyde : phenol mole ratio of 1.5 : 1, a temperature of 82.5°C, and time 3 h. However, these optimum conditions changed when the performance of the adhesives was considered in terms of the adhesive bond strengths for plywood joints. The yield, molecular weights, polydispersity, and gluability of resol resins prepared from water-catalyzed liquefied wood were lower compared with those prepared from NaOH-catalyzed ones. In most cases, the dry-bond strengths of the experimental plywood joints exceeded the minimum Japan Agricultural Standard (JAS) values. On the other hand, except at a higher formaldehyde: phenol ratio (i.e. 2.0 : 1 mole ratio), the plywood joints of all samples delaminated during 'boil-dry-boil' cyclic treatments. However, both dry- and wet-bond strengths of the plywood joints could be improved to exceed standard values by using an additional crosslinking agent, e.g. poly(methylene (polyphenyl isocyanate)) (polymeric MDI). The adhesive perfomance of the wood-based resol resins was explained on the basis of the adhesion between wood veneers and resol resin adhesives.     

杉木苯酚液化物合成热固型酚醛树脂的研究

以杉木为研究树种,对比不同料液比(木材与苯酚质量比)液化物与甲醛在碱性环境中反应,进行热固酚醛树脂制备试验。考察不同甲醛与苯酚物质的量之比值(r_F/P)、氢氧化钠与苯酚物质的量之比值(r_NaOH/P)和树脂化温度对树脂理化性能的影响。结果表明,采用料液比为1:2的液化物,r_F/P1.8,r_NaOH/P0.7,树脂化温度 80℃ 条件下合成的杉木液化物树脂压制的杨木三层胶合板满足I类胶合板强度要求,各项物理力学性能与常规PF树脂压制的板材相当,板材的甲醛释放量为 0.1 mg/L,远低于GB/T 9846-2004《胶合板》中的E₀级要求。