Changes in the reactivity of functional groups during polyesterification: A new approach to polymerization in fatty-acid-modified polyesters (alkyd resins)

Gel-point calculations based on the theory of polyesterification proposed by Flory do not agree with the experimental values even when Bobalek's concept of gel point as the first formation of infinite molecules (microgel) is used. Resins covering the range 30–60% oil length were prepared and examined by electron microscopy for the presence of microgel particles. The extent of reaction at which microgel forms is discussed in relation to the concept of equal reactivity. The conditions necessary for the formation of microgel particles and the significance of these observations to the basic assumptions used in developing the theory of polyesterification are discussed.     

醇酸树脂水分散型乳液的研究进展及性能

水分散型醇酸树脂乳液不依赖石油资源,且绿色环保。但由于水分散型树脂延长了涂膜的干燥时间且耐水性下降。寻求具有良好水分散性、适宜干燥时间及力学性能的水性醇酸树脂,是目前亟需解决的问题。综述了水性醇酸树脂的国内外研究状况,展望了其发展方向。     

Novel waterborne hyperbranched acrylated-maleinized alkyd resins

Different waterborne hyperbranched acrylated-maleinized alkyd resins (HBRAAM) were synthesized by modifying a hyperbranched alkyd resin (HBRA) with three different butylmethacrylate–maleic anhydride copolymers (BMA–MA) in the presence of p-toluenesulfonic acid (PTSA). The HBRAAM resins were characterized by using infrared analysis, iodine value, hydroxyl value, vapor pressure osmometry (VPO), dynamic light scattering (DLS), acid value, rheological analysis, differential scanning calorimetry, adhesion, flexibility, drying time, gloss, hardness and chemical resistance to solvents. The iodine value and hydroxyl value decreased with the amount of BMA–MA copolymer employed in the synthesis. Infrared analysis, VPO, and hydroxyl values allowed us to conclude that the reaction between HBRA resins and BMA–MA copolymers occurred. The viscosity of the HBRAAM resins was between 50.5 and 468 Pa s. All HBRAAM resins presented good properties of adhesion, flexibility, drying time, gloss, hardness and chemical resistance.     

Microgelation in the curing reaction of unsaturated polyester resins

A series of unsaturated polyesters were synthesized with various chemical structures and molecular weights. These unsaturated polyesters were used to study the curing reaction with styrene by using gel permeation chromatography and differential scanning calorimetry. The variation of the size of microgel particles during the curing reaction in unsaturated polyester–styrene resins was studied by using gel permeation chromatography. The size and structure of the microgels depend strongly on the polymer chain length and the number of vinyl groups on each unsaturated polyester chain. Using the differential scanning calorimetric method, the conversion of styrene and polyester vinyl groups during the reaction was measured. The experimental results of this study revealed that microgel formation has a great effect on the curing reaction of unsaturated polyester resins. © 1994 John Wiley & Sons, Inc.     

Novel renewable alkyd resins based on imide structures

New bio-based building blocks were synthesized from amino acids like lysine, glycine, and phenylalanine and from di- or tricarboxylic acids like succinic acid and citric acid, respectively. These building blocks were incorporated into alkyd resins by standard polycondensation chemistry and technology. The resulting alkyd resins were evaluated as coating resins, either by casting films from xylene or by making coatings from water-based alkyds after emulsification of the synthesized alkyd resins. The renewability content of the resins could easily be varied between 80 and ca. 95 wt%. The properties of the highly bio-based coatings look promising, some even outperforming standard commercial alkyd resins.     

Synthesis and characterisation of chlorinated rubber seed oil alkyd resins

Rubber seed oil alkyd resins of 50% oil length were prepared (sample I) and parts of it modified by direct chlorination for 30 min (sample II), 60 min (sample III) and 90 min (sample IV). The concentration of the chloride ions was found to be 0.231, 0.236 and 0.239 mol/dm³ for samples II, III and IV, respectively. The IR spectra of the samples show that chlorine enters only into the aliphatic portion of the alkyd chain by addition. The physico-chemical properties and performance characteristics of the chlorinated and unchlorinated alkyd resins were determined. The results show that the chlorinated resins are fire retardant and that they possess superior drying properties, than the unchlorinated alkyds.     

Effects of low-profile additives on the curing reaction of unsaturated polyester resins

The effect of low-profile additives (LPA), i.e., poly(vinyl acetate) (PVAC) and poly(methyl methacrylate) (PMMA), on the curing reaction of unsaturated polyester (UPE) resins was studied by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The curing reaction profiles were determined by DSC, while GPC was used to investigate the variation of the sizes of microgel particles during the early stage of curing reaction in UPE–styrene resins. The DSC experimental results indicated that the curing reaction rate decreased as the concentration of LPA increased. At a fixed LPA concentration, the curing reaction rate was slower for resins mixed with LPA possessing worse compatibility with UPE resins. During the early stage of curing reaction, the size and structure of the UPE microgels formation strongly depended on the concentration of LPA and also on the compatibility of the components in the curing system. The experimental results of this study revealed that the concentration of LPA and the compatibility of LPA with UPE resins had a strong influence on the polyester microgel formation and the curing behavior. © 1995 John Wiley & Sons, Inc.     

Molecular weight distribution in alkyd resins. Part II. Castor oil and hydrogenated castor oil alkyds

Alkyds prepared from castor and hydrogenated castor oils have been prepared direct from the oil and by first subjecting the oil to a glycerolysis reaction. The molecular weight distributions of the alkyds have been measured in solvent systems designed to separate predominantly on polarity and molecular weight. The properties of the alkyds in stoving enamels have been evaluated. The results are discussed in relation to existing theories relating processing conditions to molecular weight distribution in alkyd resins. Previous suggestions regarding the reactivity of the hydroxyl groups in the oil molecules are not consistent with the results obtained in this study.     

Studies in autoxidation: Part II. An evaluation of the by-products formed by the autoxidation of fatty acid modified alkyd resins under the influence of different promoters

A study has been made of the by-products formed during the autoxidation of a number of drying oil modified alkyd resins when catalysed by a range of different promoters. The by-product components have been separated and identified using GC-MS methods, and their composition correlated with that of the naturally occurring fatty acids present in the individual drying oils. Mechanisms are proposed to account for the formation of the components.     

Reactivity of functional groups in surface coating polymers. Part I. Hydroxyl groups in alkyd resins

The factors which can influence the availability of functional groups in polymers are considered. In particular, the importance of hydroxyl groups in the formation and Film-forming reactions of alkyd resins is discussed, and evidence is presented to suggest that the number of hydroxyl groups available for chemical reaction is not necessarily equivalent to the theoretical value. Factors which influence the availability of the hydroxyl groups are considered, and some of the properties of the alkyd are related to the available hydroxyl content.     

Reactive microspheres as active fillers for epoxy resins

Physical properties of epoxy resins filled with microparticles are presented and discussed. Microparticles were synthesized in the form of micron‐sized, crosslinked spherical particles, with an excess of reactive amino groups on their outer surface, and subsequently blended with EPON828‐3,3′DDS in different weight percents (10 and 20 wt %). Differential scanning calorimetry and scanning electronic microscopy were applied to investigate microsphere properties such as morphology, shape, size, and size distribution. Electron spectroscopy for chemical analysis was applied on particles to relate surface composition and reactivity of microspheres. Rheological, dynamic–mechanical, and mechanical properties of the cured blends were analyzed and related to the pure resin and to the same resin modified with PES180. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2031–2044, 2004     

山梨醇在醇酸树脂中的应用

本文对山梨醇的特性以及如何应用山梨醇部分代替多元醇制备醇酸树脂的过程作了介绍，对试验结果作了讨论，得出山梨醇这一新型多元醇可以用于醇酸树脂的结论。     

Dynamic mechanical properties of high nitrile resins

Dynamic mechanical measurements have become increasingly more common as an interpretative tool for identifying structure-property relationships in polymers, especially in multi-phase systems. There are many literature references citing the application of this analytical technique to the study of rubber reinforced polymers such as high impact polystyrene and aerylonitrile-butadiene- styrene. This paper illustrates further extensions of the technique to study the effects of composition and processing parameters on the mechanical relaxation behavior of rubber reinforced high nitrile resins. Storage and loss curves vs temperature are compared for three related polymer systems: (1) a high nitrile glassy copolymer, (2) mechanical blends of the glassy copolymer with rubber, and (3) a copolymer grafted onto a rubber backbone. Particular attention is given to the size and shape of the tan δ loss peak for blended and grafted resins having different rubber levels. The importance of dispersing the rubber particles during processing is also shown. Dynamic mechanical studies have shown a pronounced decrease in the size of the rubber loss peak for oriented rubber modified high nitrile resins. This is further evidence that dynamic mechanical results are sensitive to variations in processing conditions as well as resin composition.     

Structure-property relationships in PMR-type polyimide resins: 1. Novel anthraquinone-based PMR resins

Novel aromatic polyimides prepared via the polymerization of monomeric reactants (PMR) approach and incorporating anthraquinone diamines in the main chain have been characterized. Imidization and crosslinking reaction profiles have been delineated by d.m.t.a. and the high-temperature mechanical and thermal properties of the thermoset resins examined. Elevated glass transition temperatures (> 300°C) are apparent in some resins while impairment of mechanical integrity is not evident below 450°C. All resins show good thermal and thermo-oxidative stability.     

Polycarbonate resins

An outline of the history and manufacture of polycarbonate resins is followed by a discussion about resin product types anal their processing. The key properties of flex modulus, deflection temperature, and impact are those that make polycarbonate resins premier engineering resins. Like most other engineering plastics, polycarbonate resins' early commercial history was characterized by substitutions of polycarbonate resins for traditional materials, particularly metal and glass. Examples of applications are presented, More recently application developments involve ab initio selection of polycarbonate resins and article designs based on polycarbonate resin properties. In addition, “tailored” resins such as poly (estercarbonate) resins and polycarbonate resin blends have evolved to meet specific applications. The future growth of polycarbonate resins is predicted to feature few new resins, many new blends, and application developments using computer techniques.     

Synthetic resins,IV. Preparation and characterization of resins prepared from hydroxyacetophenone

New resins have been synthesized from o-hydroxyacetophenone by reaction with substituted aromatic compounds and formaldehyde in the presence of various acids and bases as catalyst following two different techniques. The polymer samples are characterized by IR spectra. The solution, thermal, and chemical properties of the resins are investigated. The solubility parameters of the resins calculated according to the investigations of Small agree well with the experimental values. The resins are found to be fairly thermostable and the energy of activation is evaluated from TG curve by applying (i) Freeman-Anderson method and (ii) Broido method.     

Photoassisted oxypolymerization of alkyd resins: Kinetics and mechanisms

A new three-component system for photoassisted oxypolymerization of alkyd resins containing a drier, a photosensitizer and a radical generator was investigated. Polymerization profiles were recorded by real-time infrared spectroscopy for a thin film exposed for 1 h to simulated sunlight radiation. The kinetic results showed that the system follows complex kinetics. Multiple regression analysis was used to model the influence of the drier, the photosensitizer and the radical generator on the final conversion and total polymerization rate during photooxidation. The mechanisms involved were studied through laser spectroscopies. Laser flash photolysis was used to measure the rate constants of reaction between the radicals formed from the photodissociation of the radical generator and the model compounds of alkyd resins, leading to the rapid formation of hydroperoxides. The photosensitizer was expected to produce singlet state molecular oxygen that reacts on the alkyd resin, and time-resolved chemiluminescence technique was used to determine the quenching rate constant of singlet oxygen by model compounds. On the basis of these results, a mechanism for the photoassisted oxypolymerization of alkyd resins is proposed that account for the all the different reaction pathways.     

Characterization of unsaturated polyester and alkyd resins using one‐ and two‐dimensional NMR spectroscopy

One‐ (1D) and two‐dimensional (2D) ¹H‐ and ¹³C‐NMR spectroscopy was used to characterize polyester and alkyd resins used in the coatings industry. The wealth of chemical composition information of the ¹H‐ and ¹³C‐NMR 1D spectra of the resins is revealed through 2D NMR experiments that spread chemical shifts in two dimensions, thus facilitating the peak assignment of the various components of the resins. It is shown that the types of polyols, acids, and vegetable oils used to modify the resins can be efficiently traced by NMR spectroscopic techniques. Information on the quantitative composition of the resins and especially the abundance of unsaturated fatty acid double bonds, which influences resin dryability and hardness, can be easily extracted from the ¹H‐NMR spectra upon successful assignment. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1881–1888, 2003     

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     

Offset printing inks based on rapeseed and sunflower oil. Part I: Synthesis and characterization of rapeseed oil-and sunflower oil-modified alkyd resins

Two sets of alkyd resins of variable oil lengths with the required properties for offset printing ink formulations, modified by sunflower and rapeseed oil, were synthetized according to the “monoglyceride” process. The influence of the acyl composition of the modifying vegetable oil and of the oil content on alkyds’ properties was determined by detailed chemical and rheological characterization. Molecular structure, size, and molecule size distribution appeared to be linked to these two factors. A comparative study with two usual linseed oil-modified alkyds led to determination of the more appropriate alkyds for applications in offset varnishes.