间苯二酚-甲醛树脂的粘合性能

通过测量在线取样的间苯二酚(R)-甲醛(F）树脂(简称RF树脂)溶液的当量粘度,来间接判断RF树脂的粘合性能。在NaOH质量分数为0.25％、反应温度为25℃的条件下,分析得出在反应时间为5h、F与R摩尔比为1．8时合成的RF树脂溶液粘合性能最好。对此试样进行了红外光谱与胶膜的成膜性能及撕裂性能分析,分析结果与测定的当量粘度数据一致,说明以当量粘度间接判定RF树脂的粘合性能是可行性的。     

国产间苯二酚-甲醛树脂的性能研究

简介间-甲-白粘合体系的粘合机理，研究国产间苯二酚-甲醛树脂的性能并与进口同类产品进行应用对比。结果表明，加入国产间苯二酚-甲醛树脂的硫化胶拉伸强度、拉断伸长率、拉断永久变形及H抽出力(包括热空气老化后)均有所提高，其它性能基本相当，完全可以等量替代进口产品应用于轮胎生产中。     

采用间苯二酚-甲醛树脂优化钢丝帘线粘合

新品种的间苯二酚-甲醛树脂中的游离间苯二酚含量极低，且不再具有吸湿性。考察了间苯二酚-甲醛树脂(Penacolite B-20-S)、硼酰化钴和不溶性硫黄的用量对钢丝粘合胶与镀铜钢丝粘合性能的影响。结果表明，树脂／钴盐粘合体系比单纯的钴盐粘合体系的粘合性能好得多。仅考虑粘合性能时，粘合体系最佳配方为：Penacolite B-20-S树脂4，硼酰化钴(活性钴)0．1，不溶性硫黄(活性)7．1，HMMM(活性)2．66。     

高效液相色谱法测定间苯二酚-甲醛粘合树脂中游离间苯二酚含量

采用高效液相色谱法测定间苯二酚-甲醛粘合树脂中游离间苯二酚含量。高效液相色谱检测波长为278nm,间苯二酚定量峰出峰时间为3.7min左右,标准曲线的相关因数为0.999 4,方法的重复性测定相对误差小于5%,再现性测定相对误差不大于8%,加标回收率为95.82%～104.43%。     

改性间苯二酚-甲醛树脂GLR-20的应用研究

试验研究改性间苯二酚-甲醛树脂GLR-20替代间苯二酚对NR胶料性能的影响,并与进口产品B-20-S进行对比。结果表明,以GLR-20或B-20-S替代间苯二酚用于间-甲-白粘合体系中,通过适当增大硫黄和促进剂用量,可以改善胶料的加工安全性,提高硫化胶的拉伸强度、撕裂强度和粘合性能;在相同条件下使用GLR-20或B-20-S,胶料的各项性能基本相当。     

烷基间苯二酚甲醛树脂与间苯二酚-80在半钢子午线轮胎带束层胶料中的应用对比

对比两种间苯二酚改性物在半钢子午线轮胎带束层胶中的应用效果。试验结果表明,应用烷基间苯二酚甲醛树脂的配方其胶料与钢丝帘线的粘合性能优于应用间苯二酚-80的配方。     

间苯二酚-甲醛干凝胶结构控制研究

利用溶胶-凝胶及常压干燥法制备了间苯二酚(R)-甲醛(F)干凝胶.通过扫描电子显微镜(SEM)、红外(FTIIR)、热重分析(TGA)研究了RF于凝胶的结构与性能,并分析了实验参数对RF的凝胶时间、干凝胶堆积密度的影响.结果表明,通过调控催化剂含量、反应物浓度、pH值可调控RF干凝胶的微观结构.RF干凝胶的堆积密度可在...     

苯酚-甲醛树脂与间苯二酚-甲醛树脂在半钢子午线轮胎纤维帘布胶中的应用比较

研究苯酚-甲醛树脂与间苯二酚-甲醛树脂在半钢子午线轮胎纤维帘布胶中的应用。结果表明:在半钢子午线轮胎纤维帘布胶中用苯酚-甲醛树脂等量替代间苯二酚-甲醛树脂后,胶料的硫化特性受到一定影响,尤其是苯酚-甲醛树脂用量增大会在一定程度上降低胶料的硫化速度;硫化胶的硬度、拉伸强度和拉断伸长率提高,老化前纤维帘线H抽出力差异不大,老化后纤维帘线H抽出力略有降低,60℃时的损耗因子略有增大。     

间苯二酚－甲醛树脂在轿车子午线轮胎胎体胶中的应用

试验研究间苯二酚-甲醛树脂在轿车子午线轮胎胎体胶中的应用。结果表明,在轿车子午线轮胎胎体胶中,以间苯二酚-甲醛树脂等量替代间苯二酚,并适当调整硫化体系,胶料的t10和t90缩短,硫化胶的粘合性能明显提高,同时可减少环境污染,降低原材料成本。     

不同生产工艺间苯二酚-甲醛粘合树脂的结构与性能对比

用热重分析仪、裂解气相色谱-质谱联用仪、红外光谱仪、凝胶渗透色谱仪和差示扫描量热仪分析3种不同生产工艺的间苯二酚-甲醛粘合树脂。结果表明,3种间苯二酚-甲醛树脂的红外光谱基本一致,挥发分、相对分子质量及其分布、结构和链段组成都有一定差异。     

Study of the reaction between resorcinol and formaldehyde

The reactions between resorcinol and formaldehyde were led in aluminium pans of a d.s.c. Perkin Elmer calorimeter. The products were separated by means of high performance liquid chromatography and identified by ¹H and ¹³C n.m.r. Depending on the catalyst concentration and molar ratio the mixtures reacted at two different temperature ranges, 317–332K and 332–366K. The heat of the reaction in the first temperature range was between 16.8 and 45.0 kJ mol^?1 for molar ratios 1:1 and 1:3 respectively. By ¹H and ¹³C n.m.r. spectroscopy five addition products were determined. The reaction heat in the second temperature range was 73.5 kJ mol^?1 and was attributed to condensation reactions. The activation energies were 95.0 and 120.0 kJ mol^?1 for addition and condensation reactions respectively. For addition, order two and for condensation, order one of reaction was established. On the basis of these foundings tentative reaction schemes were prepared.     

Recovery of purified radiocesium from acidic solution using ammonium molybdophosphate and resorcinol formaldehyde polycondensate resin

Separation of Cs⁺ from acidic solution was investigated using ammonium molybdo- phosphate (AMP) based sorbents. Four sorbents including two AMP powders and two composites prepared by coating of AMP powder on polymethylmethacrylate (PMMA) beads were used in this study. Equilibrium sorption isotherms for Cs⁺ on AMP sorbents were determined. The effect of H⁺ concentration on Cs⁺ uptake by AMP–PMMA beads was examined. Two column runs were carried out to establish the Cs⁺ separation performance of AMP–PMMA beads from 1.0 M nitric acid having Cs⁺ concentration equivalent to 10 Ci of ¹³⁷Cs per litre. Recovery of Cs⁺ from loaded AMP–PMMA column was carried out by dissolution of AMP using NaOH solution. The feasibility of ion exchange purification of the recovered Cs⁺ solution was examined using resorcinol formaldehyde polycondensate resin (RFPR). The Cs⁺ sorption isotherm on RFPR from Cs-bearing dissolved AMP solution was determined. Purification of Cs⁺ from dissolved AMP solution was studied in two column runs using RFPR in loading-elution cycles. The results of these studies are useful in formulating a scheme for the recovery of purified ¹³⁷Cs product from high level waste for large-scale utilization as a radiation source in industrial irradiators.     

尿素改性酚醛树脂胶粘剂的研究

以苯酚、尿素、甲醛为原料采用合理的工艺进行了尿素对酚醛树脂改性,对其可行性进行了初步分析。试验结果表明,所合成的尿素改性酚醛树脂贮存性好;可以在低于酚醛树脂25℃的固化温度下固化;在相同的固化温度下,UPF树脂的固化速度要快于PF树脂;用尿素改性酚醛树脂压制桦木三合板,其所压制的胶合板的各项物理力学性能与常规PF树脂胶合板性能相近,能达到GB/T 9846-1988对I类胶合板理化性能的要求;板材中的甲醛释放量低于GB 18580-2001中的E1级的要求。由于尿素的加入降低了胶粘剂的成本,尿素改性酚醛树脂综合性能优于PF树脂。     

脲醛树脂的固化研究

通过缩聚法制备出脲醛树脂,考察了制备单组分固化剂NH4C l、2%HC l、5%的H3PO4、H2O2及双组分固化剂NH4C l和2%HC l、NH4C l和5%H3PO4的使用条件,并确定了复合固化剂的配比和用量。发现双组分固化剂固化时间适宜,固化效果好。     

Study of the reaction of resorcinol,formaldehyde, and ammonia

Latex dip adhesives for nylon and rayon tire cords are prepared by reacting resorcinol and formaldehyde in aqueous solution in the presence of a catalyst for a specified time and then adding a butadience–styrene–vinylpyridine latex. Ammonia improves the stability of the latex and increases the adhesion of rubber to cord. However, a white precipitate forms if ammonia is added before the resorcinol and formaldehyde have reacted sufficiently. This paper is study of the nature of this precipitate and the conditions for its formation. By measuring the heat of reaction of formaldehyde and ammonia and, subsequently, of mixtures of formaldehyde and resorcinol to which varying amounts of ammonia were added, information on the reaction mechanism has been obtained. Ammonia reacts rapidly with formaldehyde to form an unstable intermediate, presumably trimethylolamine, which then reacts further with resorcinol to form trisdihydroxybenzylamine. This compound is also very reactive and condenses withmore ammonia and formaldehyde to give a polymer of low solubility, the composition depending on the amounts of ammonia and formaldehyde available for reaction. Elemental analyses support this concept. Primary and secondary amines react in a maner similar to ammonia.     

间苯二酚共聚PF树脂固化特性及应用效果的研究

将间苯二酚与苯酚、甲醛共聚的PF树脂胶粘剂用于生产竹胶合板,通过不同加量,研究间苯二酚对PF树脂在不同热压工艺条件下固化特性的影响。研究结果表明,间苯二酚在一定范围内对降PF树脂的固化温度、提高固化速度具有明显的作用。当间苯二酚加量达到苯酚质量的4%以上时,PF树脂可以在中温(100℃-120℃左右)条件下快速固化,竹胶合板具有良好的力学性能。     

低游离甲醛含量脲醛树脂胶粘剂的研究

研究了低游离甲醛含量脲醛树脂胶粘剂的合成新工艺,探讨了甲醛／尿素摩尔比、反应温度、pH值、以及加料的顺序等因素对脲醛树脂综合性能的影响,并采用三聚氰胺进行了改性,以提高耐水性及进一步降低产品中游离甲醛量。采用乙酰丙酮分光光度法测定了所制备胶粘剂中的甲醛含量。实验结果表明本工艺合成的脲醛树脂游离甲醛含量低、综合性能好,符合绿色环保的要求。     

Melamine‐bridged alkyl resorcinol modified urea–formaldehyde resin for bonding hardwood plywood

A powdery product was obtained by the reaction of methylolated melamine with alkyl resorcinols to form melamine‐bridged alkyl resorcinols (MARs). The effects of the addition of this powder on the bonding strength and formaldehyde emission of urea–formaldehyde (UF) resins were investigated. Three types of UF resins with a formaldehyde/urea molar ratio of 1.3 synthesized by condensation at pH 1.0 (UF‐1.0), pH 4.5 (UF‐4.5), and pH 5.0 (UF‐5.0) were fabricated. The addition of MAR to UF‐4.5 and UF‐5.0 for bonding hardwood plywood enhanced the bonding strength and reduced formaldehyde emission. For UF‐1.0, the addition of MAR adversely affected the bonding strength. However, the UF‐1.0 resin yielded the lowest formaldehyde emission of all of the UF resins in the study. The effects of the MAR addition were related to the molecular structures of the UF resins. UF‐1.0 contained a large amount of free urea, a considerable number of urons, and a highly methylene‐linked, ring‐structured higher molecular weight fraction and had a smaller number of methylol groups. Therefore, the addition of MAR was considered to cause a shortage of the methylol groups, which in turn, led to incomplete resin curing. In contrast to UF‐1.0, UF‐5.0 contained a smaller amount of free urea and a linearly structured higher molecular weight fraction and had a larger number of methylol groups. In this case, MAR was considered to effectively react with the methylol groups to develop a three‐dimensional crosslinked polymer network to enhance the bonding strength and suppress the generation of free formaldehyde to reduce formaldehyde emission. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

脲醛树脂包膜尿素的制备研究

介绍了脲醛树脂包膜尿素的制备方法,研究了脲醛树脂及植物油用量对脲醛树脂包膜尿素氮初期溶出率的影响。结果表明,包膜量越多,包膜尿素氮的溶出率越低,但使用脲醛树脂直接包膜尿素的方法并不理想;先使用植物油在尿素颗粒的表面包一层油膜,再使用脲醛树脂包膜,可大幅度降低包膜尿素氮的溶出率,在使用1.0%的植物油后,树脂包膜量为15%时,氮的初期溶出率即可低于40%,大大降低包膜材料的使用量。