Correlation between network structure and brittleness of triallyl isocyanurate resins as compared with diallyl phthalate resins

It is not possible to improve the toughness of triallyl isocyanurate (TAIC) resins by applying the procedures useful for diallyl phthalate (DAP) resins as typical allyl resins. The results obtained are discussed in connection with the network structure of TAIC resin. Thus, the polymerization of TAIC would provide a homogeneous network accompanied by the incomplete occurrence of intermolecular crosslinking reactions caused by the rigidity of polymer chains, although DAP resins would consist of the microheterogeneous networks as the agglomerate of colloidal particles.     

Synthesis and properties of ultraviolet‐curable resins via a thio–ene (thiol and allyl) addition reaction

Benzophenone diallyl ester (I) and benzophenone tetraallyl ester (II) based on 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) with allyl alcohol (AAL) were synthesized. Glycidyl methacrylate (GMA) was added to I and formed diallyl diglycidyl methacrylate (III). These BTDA‐based allyl‐containing compounds (II and III) reacted with 1,4‐butanedithiol and 4,4′‐thiol‐bisbenzene‐thiol to produce ultraviolet (UV)‐curable resins via a thio–ene addition reaction. The ester (III) was cured easily when exposed to UV or sunlight radiation without any photoinitiator and only required a lower thermal curing temperature. The diallyl ester (I) and tetraallyl ester (II) required the addition of benzophenone to increase the photosensitivity, which reduced the exposition time. These resins used AAL as a monomer to successfully reduce the oxygen effect of the photocuring. The resin BTDA–2Allyl–2GMA had a glass‐transition temperature of 166°C and a hardness of 6H. The resultant UV‐curable coatings had excellent hardness, chemical resistance, adhesion, and tensile properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1878–1885, 2002     

Properties of diallyl phthalate resin modified with phthalic allyl ester having a hydroxyl group

A phthalic allyl ester having a hydroxyl group [2‐(2‐hydroxy‐3‐allyloxypropanocarbonyl)‐allylphthalate (HDAP)] was synthesized by the reaction of phthalic monoallyl ester with allyl glycidyl ether. HDAP was added to a diallyl phthalate resin to a concentration of 30 wt % to improve the adhesive properties. These blends were cured with dicumyl peroxide. The lap shear strength of joints was measured to evaluate the adhesive properties of the modified diallyl phthalate resin to steel and copper. The lap shear strength of the diallyl phthalate resin was increased by modification with HDAP. By modification with HDAP, the lap shear strength to steel increased up to about 2.5 times that of the diallyl phthalate resin. Moreover, the lap shear strength to copper was about 3.0 times larger than that of the diallyl phthalate resin upon the addition of 30 wt % HDAP. These results suggested that the secondary hydroxyl group of HDAP (used as a modifier) formed a hydrogen bond to a hydroxyl group of water existing on the metal surface, and as a result, the adhesive strength to metals such as steel and copper increased. The thermal decomposition temperature of the modified diallyl phthalate resin was almost the same as that of the diallyl phthalate resin; on the other hand, the glass‐transition temperature of the modified diallyl phthalate resin decreased with an increasing concentration of HDAP. The electrical properties of the modified diallyl phthalate resin were almost the same as those of the diallyl phthalate resin. On the other hand, water absorption after boiling increased with an increasing concentration of HDAP. This result led to the conclusion that the secondary hydroxyl group of HDAP (used as a modifier) formed a hydrogen bond to water. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Estimation of crosslinking of diallyl phthalate prepolymer. An investigation by infrared spectroscopy

The cure of the dially phthalate prepolymer was studied by means of infrared spectroscopy. It was found that the C?C stretching band of the allyl group, which appears at 1647 cm^?1 in diallyl phthalate monomer, splits into two bands at 1645 and 1651 cm^?1 in both of the prepolymers and cured resins derived therefrom, the split band being found to be mostly useful to investigate the highly cured resin system of diallyl phthalate. On the basis of the split band, α is defined as a new parameter expressing a degree of residual unsaturation of diallyl phthalate prepolymers as well as highly crosslinked polymers, as revealed experimentally. Further, α proved to correlate closely with other parameters such as the iodine value measured for the prepolymers, and swelling weight ratio or Barcoal hardness (hot) measured for the cured resins, it becoming evidently a convenient parameter to examine the degree of crosslinking of diallyl phthalate resin system. The effect of metal molds employed upon cure of prepolymers was also elucidated from the measured α values.     

Preparation and cured properties of diallyl phthalate resin modified with epoxy resin and allyl ester compound having carboxylic acid

An epoxy resin was blended with a diallyl phthalate resin to improve the adhesive properties and the fracture toughness. A compatibilizer was used to reduce the decrease in heat resistance. An allyl ester compound [1,4‐diallyloxycarbonyl‐2,5‐benzenedicarboxylic acid (DAPY)], which reacted with the diallyl phthalate resin and epoxy resin to have allyl groups and carboxylic acids on the end of the molecular chain, was synthesized as a compatibilizer by the reaction of pyromellitic dianhydride with allyl alcohol. These blends were cured with dicumyl peroxide and triethylamine. By modification with the epoxy resin and DAPY, the lap shear adhesive strength to steel increased up to about 3 times that of the diallyl phthalate resin. These results suggest that the secondary hydroxyl group generated by the addition reaction of the epoxy resin and DAPY and the secondary hydroxyl group existing in the molecular chain of the epoxy resin formed hydrogen bonds with the hydroxyl group of water existing on a metal surface, and as a result, the adhesive strength to metal such as steel increased. The fracture toughness of the diallyl phthalate resin was increased by modification with the epoxy resin. The reason for this result was that the flexibility increased because the crosslinking density became small by modification with the epoxy resin. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Unsaturated polyester resins with different allyl ethers as crosslinking built-in monomers

The effect of the structure of allyl ethers used as built-in monomers of unsaturated polyester resins on the properties of the coatings obtained have been studied. It was found that high hardness of the coatings cured in air using photoinitiators was achieved for the resins with polyfunctional allyl ether monomers incorporated into polyester molecules as the end groups or as the pendant geminal groups. The influence of the presence of a cobalt organic salt on the hardness of the coating from unsaturated resins has also been studied. The extent of crosslinking for the copolymerization of fumaric esters with allyl ethers in air increases, and a smaller amount of photoinitiator may be used when cobalt (II) naphthenate is present in the resin. The results are discussed in terms of the oxidation of allyl ethers and redox cleavage of peroxides formed, leading to an increase in the rate of copolymerization of allyl ethers with fumarate esters. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2031–2039, 1998     

Thermosetting matrices for composite materials based on allyl/propagryl substituted novolac resins

A new type of modified thermoset resins was synthesized by Williamson reaction from novolac resin and a mixture of allyl and propargyl chlorides of the different ratios with total allyl/propargyl substitution 50 %. The compositions of the resins were defined by nuclear magnetic resonance (¹H NMR) spectroscopy, and the dependence of the cured material properties on the composition was established. An increase of a propargyl content resulted in char yield raise, and the maximum value had been found for propargylated resin which was 60 %. By differential scanning calorimetry (DSC) analysis of the curing process, it was demonstrated that exothermic enthalpy could be adjusted by varying the content of propargyl and allyl groups in the resin. It was shown that the resin substituted with allyl only ether could not be cured without decomposition, but an introduction of propargyl groups in allyl ether-modified resin allowed to obtain cured samples and thus to develop a new type of thermosetting resins.     

Thermosetting allyl resins derived from soybean fatty acids

A novel class of thermosetting resins based on allylated and transesterified epoxidized soybean oil (AE‐ESBO) curable by radical mechanism was developed. The AE‐ESBO was prepared from ESBO by oxirane ring‐opening and then transesterification with allyl alcohol. A family of rubbery to glassy resins was prepared by radical copolymerization of AE‐ESBO with different concentrations of maleic anhydride (MA). Glass transition temperatures (T_g) of these resins ranged from below room temperature to about 130°C based on the amount of MA. In spite of the presence of anhydride groups, water absorption was low <2% even when maleic anhydride was 30% of total weight. Low sol content after extraction and low swelling in toluene indicated high crosslinking density. Tensile moduli of these resins were up to 1.4 GPa and tensile strengths up to 37 MPa. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

邻苯二甲酸酐与烯丙醇酯化反应动力学

为给邻苯二甲酸二烯丙酯的中试放大乃至工业生产提供必要的动力学数据支持,在前期工艺探讨与优化工作基础之上,文中较为系统地研究了无催化剂和以对甲苯磺酸为催化剂条件下,邻苯二甲酸酐与烯丙醇合成邻苯二甲酸二烯丙酯的反应动力学.经模型简化,分别得出了第2步关键反应在这2种反应条件下的反应级数、反应速率常数、表观活化能和指前因子....     

Properties of novel diallyl phthalate resin modified with sulfur‐containing allyl ester compounds

Sulfur‐containing allyl ester, which reacts with diallyl phthalate (DAP) resin to have allyl groups, was synthesized by the reaction of allyl phthalic acid with bisphenol having sulfur atoms. The sulfur‐containing allyl ester compound was blended with DAP resin to improve the adhesive properties to copper. By modification with sulfur‐containing allyl ester compound, the T‐peel adhesive strength and the lap shear adhesive strength to copper was improved. In particular, the adhesive strength was greatly improved when the resin was modified with the allyl ester compound having a disulfide bond (?S?S?) (DADS). It is concluded that this result is due to the improvement of the interfacial adhesive strength because the sulfur atom was found to be located in the surface of the copper by Fourier transform infrared (FTIR) analysis. The glass transition temperature (T_g) and the thermal decomposition temperature (T_d) of the cured DAP resin modified with DADS slightly decreased with increasing concentration of DADS. The lowering of T_g is because the crosslinking density of the DAP resin modified with DADS is smaller than that of DAP resin. Moreover, from thermogravimetric analysis, the lowering of Td of the DAP resin modified with DADS is because DADS is likely to pyrolyze. © 2013 Society of Chemical Industry     

烯丙基化合物改性双马来酰亚胺树脂的研究进展

双马来酰亚胺(BMI)树脂以其优异的机械和热稳定性能广泛用于航空航天等领域,但纯BMI熔点高、韧性和溶解性差,不能满足实际使用要求,必须对其进行改性。探讨了烯丙基化合物改性BMI的反应机理,包括"Ene"反应、Diels-Alder反应以及体系中可能存在的其他反应;并分别概述了二烯丙基双酚A(DABPA)、含硼烯丙基化合物、烯丙基酚醛树脂、烯丙基酚氧树脂及其他烯丙基化合物改性BMI体系的研究进展和改性效果。     

Studies on simultaneous curing of nadimides and allyl nadic-imides and thermal behaviour of cured resins

The effect of composition and chemical structure of addition polyimides on thermal characteristics was investigated using commercially available allyl nadic-imide resins and phosphorus-containing nadimide resins. Thermogravimetric analysis, in N₂ atmosphere, of resins cured at 300°C for 1 h revealed improvement of thermal stability.     

对甲苯磺酸催化合成邻苯二甲酸二烯丙酯

以对甲苯磺酸作催化刑,由邻苯二甲酸酐和烯丙醇反应合成邻苯二甲酸二烯丙酯。邻苯二甲酸酐与烯丙醇的物质的量比为1：4,对甲苯磺酸的质量为邻苯二甲酸酐质量的13％,回流分水16h,产品邻苯二甲酸二烯丙酯的收率可达95．7％。     

Toughening of epoxy resins by modification with aromatic polyesters

Aromatic polyesters, prepared by the reaction of phthalic or isophthalic acids and α,ω-alkanediols, were used to reduce the brittleness of bisphenol-A diglycidyl ether epoxy resin cured with methyl hexahydrophthalic anhydride. These polyesters were effective as modifiers for toughening of the epoxy resin system. The most suitable composition for modification of the epoxy resins was inclusion of 20 wt % of poly(ethylene phthalate) (MW 7200), which resulted in a 150% increase in the fracture toughness (K_IC) of the cured resin at no expense of its mechanical properties. The effectiveness of poly(alkylene phthalate)s as modifiers decreased with increasing the chain length of alkylene units. The toughening mechanism was discussed based on the morphological and dynamic mechanical behaviors of the modified epoxy resin system.     

Novel oxidatively drying urea resin. I. Drying properties of urea resins prepared from N,N′-bis(methoxymethyl) urea and alcohols containing allyl ether groups

A new type of urea resin prepared by copolycondensating N,N′-bis(methoxymethyl) urea with an alcohol containing allyl ether groups have been studied and found to have adequate drying properties when used for surface coating purposes. The drying behavior of the resins can be controlled by conventional drier metals, cobalt being an efficient catalyst. Calcium was found to have a synergetic effect with cobalt on drying, zinc and lead had no synergetic effect, and manganese and sodium hydroxide acted as drying inhibitors. Increasing the amount of allylic alcohol in the monomer mixture and higher molecular weight led to the formation of a faster drying resin. The molecular weight distribution of the resins was found to have an effect on the surface coating properties. It was found that for resins having an equal drying rate those with a broader molecular weight distribution had higher solution viscosities. Resins with a narrow molecular weight distribution were also found to be advantageous when formulating coating compositions containing a minimum concentration of solvents.     

邻苯二甲酸二烯丙酯的合成研究

以烯丙醇和邻苯二甲酸酐为原料,合成了邻苯二甲酸二烯丙酯,并用IR1、HNMR对邻苯二甲酸二烯丙酯进行了结构表征。系统研究了烯丙醇和邻苯二甲酸酐的摩尔比、对甲苯磺酸用量、阻聚剂种类及用量、带水剂用量对反应的影响,得到的较佳反应条件(以邻苯二甲酸酐0.1 mol计),即:醇酐摩尔比2.4∶1,对甲苯磺酸0.8 g,4-羟基-2,2,6,6-四甲基哌啶氮氧自由基0.32 g,甲苯35 mL,在回流条件下反应至无水生成,在该条件下产物收率可达96.5%。     

聚三唑酯树脂的合成及其性能

通过酯化反应合成丁二酸二炔丙醇酯(DPS)、间苯二甲酸二炔丙醇酯(DPIP)、对苯二甲酸二炔丙醇酯(DPP),与三官能团叠氮化合物(TAMTMB)反应,制备了3种热固性聚三唑酯(PTAE)树脂,研究了树脂的加工特性、固化行为、树脂固化物的力学性能,制备和表征了T700单向碳纤维增强PTAE树脂复合材料。结果表明,PTAE树脂具有良好的加工性能,可在较低温度(80℃)下固化;固化后的PTAE树脂的玻璃化转变温度(Tg)受主链结构影响,3种树脂的Tg均高于140℃,浇铸体弯曲强度高于170 MPa,T700单向纤维增强PTAE树脂复合材料的常温弯曲强度高于1500 MPa。     

Waterborne unsaturated polyester resins

The transformation of solvent soluble unsaturated polyester resins into resins able to form stable water dispersion is presented in this paper. The methods of modification are discussed, consisting of the introduction of polar hydrophilic groups such as carboxylic and sulfonic ones (sodium 5‐sulfonatoisophthalic acid) into the resin molecule, which ensure good tolerance with water. Instead of styrene, glycerol monoethers of allyl alcohol and unsaturated fatty alcohols were used as reactive built‐in crosslinking monomers for resin modification. The influence of the resin composition and method of synthesis on the dispersion stability and properties of photocurable lacquer coatings obtained from the waterborne resins were investigated.     

Kinetics and flow of diallyl phthalate resins

The analysis of molding operations for thermosetting polymers requires knowledge of the rheology and reaction rates of the materials. The purpose of this research was to measure kinetic and rheological data on diallyl phthalate resins and to integrate these results into models describing the flow behavior. The chemical kinetics of the curing reactions were derived from calorimetric measurements taken with a differential scanning calorimeter. The rheological data were measured with a mechanical spectrometer equipped with eccentric rotating discs. A model based on the theory of ideal rubber elasticity was used to correlate the elastic storage modulus with reaction time and temperature. For the region below the gel point, the dynamic viscosity exhibited a power law dependence on angular frequency and an Arrhenius dependence on temperature.     

Selective conversion of allyl alcohol to oxygenates and hydrocarbons using ion exchanged zeolite Y

The reaction of allyl alcohol using zeolite Y as catalyst has been investigated and it is shown that it can be converted into a range of products, including hydrocarbons, acrolein and diallyl ether. Control of product selectivity can be achieved by careful selection and manipulation of the charge balancing cation, a series of catalysts can be prepared which, for the conversion of allyl alcohol, lead almost exclusively to the initial formation of either (a) C₂-C₆ hydrocarbons and coke (H-NaY), (b) acrolein (H-CsY), (c) propene (Li-NaY) or (d) diallyl ether (Cs-NaY). The effects of addition of H₂ and H₂O to the reactant are described and discussed with respect to the reaction mechanism and the reaction of potential intermediates (2-propanol and propene oxide) is also described. Mechanisms of formation of the major products are proposed that involve the concerted action of Brønsted acid and basic sites within the zeolite. In particular, since the addition of H₂O does not affect the product distribution, it is considered that the mechanism of hydrocarbon formation does not involve the allyl cation as an intermediate.