Novel oxidatively drying urea resin. II. Surface coating properties of N,N′-bis(methoxymethyl) urea-based air-drying resins

The surface coating properties of the air-drying urea resins prepared by polycondensating N,N′-bis(methoxymethyl) urea (BMMU) with trimethylolpropane diallylether (TMPDA) and 2-ethylhexanol (2EH) were studied. It was found that the thinnability of the ethanolic resin solutions with water decreased with increasing molecular weight and the degree of modification of the resins with TMPDA and 2EH. The viscosity of the ethanolic resin solutions increased with the molecular weight but was independent on the resin's degree of modification. The drying performance was improved with increasing molecular weight and decreasing modification with 2EH. The hardness of the paint films was proportional to the modification of the resins with TMPDA and the molecular weight. 2EH led to the plasticization of the coatings. The water resistance of the paint films was improved with increasing modification with 2EH and molecular weight of the resin. The analysis of the elastic properties of the hardened films was not possible due to the scatter of the experimental data. The comparison of the amino resin paints to some commercial paint products indicated that BMMU-based resins having good drying performance and adequate water resistance at the same time can be prepared. Neutral ethanolic and aqueous ethanolic resin solutions were found to have a good storage stability as determined by following the viscosities of the solutions and the hydrolysis resistance of the resins.     

Water-soluble sulfonated amino–formaldehyde resins. IV. Melamine–urea resins: Synthesis and properties

The factors affecting the preparation and the properties of sulfonated melamine urea–for-maldehyde resins were studied. The resins weresynthesized using a four-step procedure previously used in preparing sulfonated melamine formaldehyde resins. The melamine–urea resins required higher hydroxymethylation and condensation temperatures as the percentage of urea increased. The molecular weight distribution of the prepared resins revealed the formation of low molecular weight species in increasing amounts with higher percentages of urea. The effectiveness of the prepared resins as dispersants for concrete mixes was found to be lower than the pure melamine resins; however, it was possible to enhance them by raising the ratio of sulfonated groups in the resins.     

Reaction variables and a proposed mechanism of open-pore urea/formaldehyde structure formation

Formation of open-pore urea/formaldehyde structures from nonetherified urea/formaldehyde resins involves reaction of one or more methylol groups with other methylol or amino groups. The structure formation proceeds through particle formation and growth until all the resin is consumed. A strong acid is preferred for achieving a porous structure in urea/formaldehyde resins; weakly ionized acids produce structures with low yield. Colloidal instability is an asset in porous structure formation. An 80:20 polyethylene oxide/polypropylene oxide block copolymer of approximate molecular weight 8500 has been found to be an entropic-type destabilizer in the formation of porous structures.     

An investigation on synthesis of alkyd resin with sorbitol

Sorbitol, as an abundant, cheap and renewable resource, is considered as a potential raw material for the manufacture of alkyd resin. In this study, the kinetics on preparation of alkyd resin using phthalic anhydride, sorbitol and soya bean fatty acid as raw materials is investigated. Three kinds of sorbitol based alkyd resins (SAR) samples having fatty acid content (OL_f) of 42% (SAR1), 52% (SAR2) and 62% (SAR3) were prepared with phthalic anhydride, sorbitol aqueous solution and soya bean fatty acid using fatty acid method. Kinetic studies showed that the initial and latter stages of the reaction follow a second-order rate law. The second-order rate constants were found to be of the order of 10⁻⁵ g/mg KOH/min. Molecular weight and polydispersity index were determined by GPC and end-group analysis. The number average molecular weight of the alkyd resins ranged from 1435 to 1626 and the weight average molecular weight ranged from 3041 to 3648. A large polydispersity index was found in a range from 2.12 to 2.24. The varnish of alkyd resin SAR1 containing 50% 200# solvent gasoline and 1.25% cobalt naphthenate (drying agent) by weight dried faster than the others. The physical and chemical film properties of the sorbitol based alkyd resins were determined and compared with standard alkyd resins. The results showed that the performance of alkyd resin having fatty acid contents (OL_f) of 42% (SAR1) was almost the same as the standard alkyd resins. It could be a choice binder for alkyd resin paint and helpful to reduce production cost.     

The chemistry of furfuryl alcohol resins

Furfuryl alcohol resins contain a broad spectrum of compounds. The distribution of these compounds in a given resin varies with the manufacturing conditions. A resin containing a high proportion of low molecular weight constituents has been prepared and separated into fractions. Twelve compounds were separated from the resin; four of these are new compounds. The lower molecular weight constituents can be arranged into four major classes: polyfurfuryl alcohols, polyfurfuryl furans, methyl-substituted polyfurfuryl furans, and polyfurfuryl ethers.     

Preparation and characterization of water reducible alkyd resin/colloidal silica nanocomposite coatings

In this study, water reducible alkyd resins containing different amounts of colloidal silica were synthesized for the first time. In order to achieve this, alkyd resin, which has an oil content of 35%, was prepared with tall oil fatty acid, isophthalic acid, trimellitic anhydride, and trimethylolpropane. The alkyd resin was neutralized with triethylamine, and was dissolved in an isobutyl alcohol-isopropyl alcohol-butyl glycol mixture to produce 75% (wt.) solution, which was called stock alkyd resin. The stock alkyd resin was diluted with water to 50% (wt.) concentration with water and colloidal silica mixture in order to prepare an alkyd solution containing 0%, 5%, 10%, 15% and 20% colloidal silica. Then the effect of the silica nanoparticle addition on the surface coating properties, thermal behaviors and surface morphologies of water reducible alkyd resins was investigated. As a result, the addition of colloidal silica has improved surface coating properties and thermal behaviors of nanocomposite water reducible alkyd resin.     

The effect of alkyd resins on the properties of AA‐NC semi‐IPNs as binders in wood finish

Wood coatings of AA‐NC semi‐interpenetrating polymer networks (semi‐IPNs), made from acid curing amino‐alkyd resins (AA) and nitrocellulose (NC), were prepared by sequential polymerization method. To investigate the effects of oil length on the properties of AA‐NC semi‐IPNs, three grades of alkyd resins (Alkyd) containing 38, 48, and 58% oil were synthesized with phthalic anhydride, glycerol, and soybean oil, employing alcoholysis method. The butylated urea formaldehyde resin (UF) and melamine formaldehyde resin (MF) were also prepared in this study. The AA‐NC semi‐IPNs were maintained at a weight ratio of AA : NC of 25 : 75, where the AA was the composition of MF : UF : Alkyd of 7.5 : 22.5 : 70 (by weight), and 10% of p‐toluene sulfonic acid solution (concentration, 25% in isopropyl alcohol) based on the weight of amino resins was added as acid catalyst. The properties of coatings such as viscosity, drying time, and gel time, and the properties of films including adhesion, hardness, abrasion resistance, impact resistance, tensile strength, released formaldehyde, lightfastness, solvent resistance, and durability were examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1923–1927, 2004     

Variation of MUF and PMUF resins mass fractions during preparation

The variation of molecular mass distribution with the progress of the reaction was studied for the following: (i) sequential‐type melamine–urea–formaldehyde (MUF) resin formulations in which the sequence of addition of chemicals follows well‐defined species reactivity principles; (ii) a nonsequential MUF formulation in which simultaneous melamine and urea competition for formaldehyde yields a MF resin cocondensed with small amounts of urea. This resin became soaked with reacted and unreacted monomeric urea species. (iii) A PMUF resin, namely a MUF resin with a small proportion of phenol (7.8% by weight on melamine and urea) cocondensed with the main MUF fraction. All the formulations used were industrial resins formulations in current use. Development and variation of molecular mass fractions, from which performance and other useful resin parameters depend, have been found to depend on the type of resin formulation used for these type of aminoplastic resins. The two very different MUF resin formulations yielded different variations in molecular mass fractions during the progress of the reaction and during the so‐called ambient temperature “maturing” of the resin. The PMUF resin also showed both similar and different fractions present during manufacturing and during short term ageing at ambient temperature. While similarities in recurrent fractions and in trends are common to all the three different formulations, differences between them are also clearly observed. A major proportion of the reaction of some of the aminoplastic resins examined also occurs on ageing (i.e.“maturing” of the resin at ambient temperature), this appearing to be an essential phase of the resin preparation process. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4842–4855, 2006     

Synthesis of four-component acrylic-modified water-reducible alkyd resin: investigation of dilution ratio effect on film properties and thermal behaviors

This study investigated the effect of the dilution ratio on film properties of acrylic-modified water-reducible alkyd resins. First, new four-component acrylic-modified alkyd resins based on 1,3-propanediol containing 40% of the equivalent amount of acrylic copolymer to alkyd resin were synthesized using the fatty acid method. The synthesized acrylic-modified alkyd resin was then dissolved in isopropyl alcohol (IPA) at various ratios and further diluted using distilled water at various ratios to obtain by-weight percentages of 70/50, 70/60, and 80/60 of solid content to IPA and water, respectively. Films of the modified alkyd resins were prepared, and cured at 150°C for 1 h, then their physical and chemical surface coating properties and thermal behaviors were investigated. The best results were obtained for the by-weight percentages of 80/60.     

Viscoelastic properties of epoxy resins. III. Effect of molecular weight of antiplasticizers in highly crosslinked antiplasticization system

Antiplasticization, defined as an increase in glassy modulus of polymers upon dilution with low molecular weight compounds, was studied for highly crosslinked epoxy resins. A series of oligomers with average molecular weight 500–4000 was incorporated with epoxy resins for elucidating the effect of their molecular weight on antiplasticization. The antiplasticization was found to be dependent on the molecular weight of the oligomers used. It was most evident when the lowest molecular weight oligomer was incorporated, and seems to be suppressed by increasing molecular weight of the oligomers. These results were discussed in correlation with the behavior of dynamic mechanical properties and the changes in specific volume as a function of the epoxy resin and diluents.     

The influence of structural modification and composition of glycidyl carbamate resins on their viscosity and coating performance

The synthesis, characterization, and coatings performance of a series of glycidyl carbamate (GC) resins synthesized from a hexamethylene diisocyanate biuret resin, glycidol, and alcohols were explored. The partial replacement of glycidol with alcohols was explored as a way to reduce the viscosity of multifunctional GC resins. Six modified GC resins were obtained by replacing one-third of the glycidol with alcohols and ether alcohols. The modified GC resins were characterized using FTIR and ¹³C NMR. The alcohol-modified GC resins had significantly lower viscosity than that of the control GC resin. The effect of amount of alcohol modifier on resin viscosity was also studied by making a series of resins with different levels of modifier. Both amine-cured and self-crosslinked coatings were prepared from the resins. Coating properties such as hardness, impact strength, methyl ethyl ketone double rubs, flexibility, and adhesion were studied. Differential scanning calorimetry and thermogravimetric analysis were also used to study the thermal properties of the coatings. The resin structures and their coating performance showed an excellent correlation. The coating performance was found to be governed by the type of modifier, structural compositions of the modifier in the resins, type of amine crosslinkers, and techniques of crosslinking used.     

Chain-extended bismaleimides. II. A study of chain-extended bismaleimides as matrix elements in carbon fiber composites

A series of chain-extended bismalemide resins as matrix elements in carbon fibers were cured and characterized in terms of their thermal and thermomechanical properties. The cured resins were stable up to 430°C and EDABMI/MDA has the highest T^g value and the lowest loss modulus value. To understand the compatibility and the degree of adhesion between the resin and the fiber, their surface properties were determined in terms of the surface energy component and single-fiber pull-out tests. The surfaces of the resins were found to have a basic character. The resins containing ether groups have a higher degree of basicity than does the resin containing methylene groups. Similarly, an increasing trend in the interlaminar shear strength (ILSS) and the work of adhesion values were observed with the increasing number of the ether groups in the resin structure. © 1996 John Wiley & Sons, Inc.     

Improving coating characteristics of palm stearin alkyd by modification with ketone resin

The present study describes the modification of long oil palm stearin based alkyd resin through blending it with a commercially available ketone resin to improve its coating characteristics. The effects of blending on air drying time, hardness, adhesion, gloss, impact strength, chemical resistance and thermal behavior of dried films of blends were investigated and compared to virgin alkyds. It was found that blending results in modifying coating characteristics of palm stearin based alkyd resins, significantly. Best result was observed for weight ratio 70:30 of alkyd and ketone resins.     

Synthesis, characterization, and analyses of mechanical, adhesion, and thermal properties of polysiloxane resin modified with segmented polyurethane

Novel heat-resistant coating materials with excellent adhesion properties were prepared by modification of polysiloxane resin (PSil) with a pre-synthesized tailored polyurethane/polyurea copolymer end-capped with siloxane (PU). The modification was achieved by crosslinking the hydroxyl group of PSil and ethoxy group of PU in the presence of di-n-butyltin dilaurate. The chemical structure of PU was analyzed by Fourier Transform Infrared and Hydrogen-1 Nuclear Magnetic Resonance spectroscopic methods. A series of modified silicone resins (MSRs) have been synthesized and investigated. The molecular weights of the resins were determined by means of gel permeation chromatography. The morphology of the MSR studied by scanning electron microscopy has shown that the resin containing 30% of PU has a small particle size and a good particle size distribution. The adhesion and the mechanical properties of the resins containing 20, 30, and 40% of PU have shown a good performance. Using thermogravimetric analysis, the thermal properties and the thermal degradation of the MSR were investigated.     

环氧-胺/环氧-丙烯酸酯复配阴极电泳涂料

合成了环氧-胺阳离子树脂和环氧-丙烯酸酯接枝阳离子树脂,以这2种树脂共混制备了有机挥发物含量低的复配树脂用作水性汽车阴极电泳涂料。采用FTIR、DSC、TG和SEM分析研究了几种树脂的化学结构、影响漆膜玻璃化温度(Tg)、热稳定性等的因素并对漆膜的的表面形态和断面形态进行了观测。结果表明,复配树脂漆膜的综合性能最好;当环氧-丙烯酸接枝树脂的质量分数为80%时,复配漆膜有单一的Tg,说明2种树脂相容,从而对提高复配漆膜的综合性能起到协同作用。     

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     

电石法与乙烯法PVC材料的性能对比

研究了电石法与乙烯法PVC材料性能的差别,比较了二者的分子质量及其分布、流变性能和力学性能。针对试验中考察的PVC树脂样品而言：①电石法PVC树脂的分子质量比乙烯法PVC树脂低,其分子质量分布比乙烯法PVC树脂宽;②电石法PVC干混料的塑化性能优于乙烯法PVC干混料;③电石法与乙烯法PVC树脂的力学性能相差不大。     

桐油改性双环戊二烯不饱和树脂的合成及其性能研究

采用催化水解加成法合成了桐油改性双环戊二烯不饱和聚酯,通过对桐油滴加前后不饱和聚酯的凝胶色谱及红外表征,证实了桐油与不饱和聚酯分子链中的双键发生了Diels-Alder反应。研究了桐油加入量对树脂涂膜的气干性、附着力、柔韧性、硬度、耐磨性及树脂耐热性能的影响,并确定了桐油的最佳加入量。结果表明:较未改性的双环戊二烯不饱和聚酯(DCPD-UPR),桐油基DCPD-UPR的涂膜具有更好的气干性、柔韧性、粘接性和耐磨性,并且桐油基DCPD-UPR的耐热性也优于未改性的DCPD-UPR。     

Resins and additives for powder coatings and alkyd paints, based on renewable resources

Due to limited fossil resources and an increased need for environmentally friendly, sustainable technologies, the importance of using renewable feedstocks in the paint and coatings area will increase in the decades to come. This paper highlights some of the perspectives in this area. Alkyd resins for high-solid paints and reactive diluents, completely based on commercially available renewable resources, were prepared and characterized. Alkyd resins based on sucrose and unsaturated fatty acids or oils showed a low intrinsic viscosity, making them suitable to be used in high-solid alkyd paints. Reactive diluents based on similar starting materials showed excellent properties with regard to thinning behavior and effect on drying characteristics. Powder coating polyester resins were synthesized, starting from isosorbide and diacids. Polyester resins with glass transition temperatures up to 70°C were obtained. Incorporation of small amounts of other diols and trifunctional components was found to improve color and coating properties. In order to create completely renewable resin systems, the development of renewable drying agents for alkyds and crosslinkers for powder coatings is in progress. Presented at the XXVIII FATIPEC Congress, in Hungary, June 2006.     

Preparation and performance of new antifouling resins containing BIT group

New acrylate grafting epoxy antifouling resins containing benzoisothiazoline ketone (BIT) group were successfully synthesized, and their structures and performances were determined. Experimental data indicated that the new acrylate grafting epoxy antifouling resins have a strong bonding to the cured epoxy resin coating through chemical reaction and self-stratifying. And the paint prepared by using the new resin as matrix has excellent self-polishing and antifouling properties. Especially its antifouling period could be modified by changing the weight ratio of the usage of the mixed monomers and epoxy resin in the preparing process of the acrylate grafting epoxy antifouling resins.