Butanediol Diglycidyl Ether Research Articles

Studies of epoxy resin systems: Part D: Fracture toughness of an epoxy resin: A study of the effect of crosslinking and sub‐Tg aging

AbstractThe fracture toughness of an epoxy resin system, diglycidyl ether of butanediol, DGEB, cured with 4‐4′ diaminodiphenyl sulphone, DDS, has been studied by varying the crosslinking density and state of aging. A stable, but rough, crack propagation was observed with specimens that were 99 percent cured and quenched. When the extent of curing was less than 99 percent or the material was aged for more than 20 min at 62°C, crack propagation was of the unstable stick‐slip nature. Aging was found to decrease the initiation fracture toughness dramatically, but the arrest fracture toughness was almost unchanged. This result was associated with a change of relaxation strength of the primary, a, transition with aging. An increase of crosslinking density was found initially to reduce the fracture toughness of this epoxy resin, but the fracture toughness increased after 87 percent of curing. The initial decrease of the fracture toughness was attributed to a decrease of relaxation strength of the primary transition (i.e., the area under the α‐relaxation peak), while the increase of the fracture toughness after 87 percent curing was explained by the onset of the stablerough crack propagation, Micrographs taken by scanning electron microscopy‐showed possible existence of blunting during crack propagation and a decrease of blunting with the extent of aging.

Studies of epoxy resin systems: Part C: Effect of sub‐Tg aging on the physical properties of a fully cured epoxy resin

AbstractThe effect of sub‐Tg aging on the properties of an epoxy resin system, diglycidyl ether of butanediol, DGEB, cured with 4‐4′ diaminodiphenyl sulfone, DDS, has been studied. Aging was found to increase the DSC (differential scanning calorimetric) endothermic peak, the density, and the upper yield point. In contrast, the lower yield point was relatively unchanged. This result, together with the observation of the elimination of the DSC endothermic peak by deformation and the absence of a yield point after deformation, suggested that the aging effect was eliminated by deformation. The thrermally stimulated depolarization (TSD) α‐peak was found to decrease in strength with aging time. All of the observations were best rationalized on the basis of the free‐volume concept.

Studies of epoxy resin systems: Part B: Effect of crosslinking on the physical properties of an epoxy resin

AbstractAn epoxy system consisting of diglycidyl ether of butanediol, DGEB, cured with 4‐4′ diaminodiphenyl sulfone, DDS, has been used for a study of the effect of crosslinking density on the properties of the epoxy resin. Because of the low curing rate at room temperature and the low glass‐transition temperature, this system was amenable to a wide range of controlled cross‐linking density. The crosslinking density was monitored by FTIR (Fourier transform infrared spectroscopy), which followed the change in concentration of the epoxy groups during the curing reaction. The bulk density was found to increase linearly with the crosslinking density. The modulus, the upper yield point, the lower yield point, and the degree of retraction of a deformed sample all increased with the degree of crosslinking. The thermally stimulated depolarization (TSD) β‐peak was found to vary with crosslinking density, but the γ‐peak was not changed. The TSD a peak was found to decrease in strength, but increased in temperature as the crosslinking density increased. This observation suggests that TSD measurements arc a good monitor of crosslinking density of epoxy resins, particularly near the final stage of the crosslinking reaction.

Ultrasonic properties of some diamine cured aliphatic epoxy polymers

Longitudinal sound speed and absorption were measured from 0° to 100°C at a frequency of 2 MHz on an aliphatic epoxy resin (butanediol diglycidyl ether) crosslinked with four different curing agents—three aliphatics of differing chain lengths and one aromatic. The ultrasonic properties were found to be dominated by the glass transition in a manner qualitatively similar to linear polymers. In the aliphatic series, the ultrasonic properties all fell on the same master curves when plotted as functions of T − T g , but the aromatic curing agent was qualitatively different. For a single relaxation time model, the sound absorption peak for the aliphatic series would be 55 dB cm −1. The measured peak of 28 dB cm −1 shows that the glass transition involves a distribution of relaxation times.

Isolation of rat liver phenylalanine hydroxylase using a novel pteridine matrix

Phenylalanine hydroxylase has been isolated quantitatively from rat liver by the following purification sequence: (a) acetic acid extraction, (b) ethanol fractionation, (c) ammonium sulfate precipitation, (d) filtration through Sephadex G-100, and (e) affinity chromatography on a matrix containing 2-amino-4-hydroxy-6,7-dimethyl-5,6,7,8-tetrahydropteridine bound to Sepharose via a butanediol diglycidyl ether linkage. Steps (d) and (e) were carried out in 0.01 m tris(hydroxymethyl)methylaminopropanesulfonic acid (Taps) buffer solutions, pH 8.5, containing 0.1 m sodium chloride and 0.001 M dithioerythritol. The eluent for step (e) additionally contained 0.04 mg/ml catalase, and enzyme recovery was achieved when 0.1 m phenylalanine was introduced. Enzyme and phenylalanine separation was accomplished by sequential passage through columns of the affinity matrix and Sephadex G-25. The hydroxylase exhibited: a concentration-dependent specific activity of 1 to 6 μmol/min/mg; homogeneity by sodium dodecyl sulfate-polyacrylamide electrophoresis ( M r = 49,000 ± 2000), but heterogeneity (two major bands, M r = 120,000 ± 15,000 and 200,000 ± 20,000) when sodium dodecyl sulfate was omitted; a pH optimum of 6.5, and stability which was markedly enhanced by the presence of the Taps buffer, anaerobic conditions, catalase, and radical scavengers such as 3,5-di- tert-butyl-4-hydroxybenzyl alcohol.

Crosslinking of Starch Xanthate IV. Epoxy Resin and Diepoxide Thickeners for Xanthate and Starch

AbstractAqueous solutions of starch xanthate (of varying degree of substitution), butanediol dixanthate or alkali‐gelatinized starch were reacted with a diepoxide, such as butanediol diglycidyl ether to get viscous gels. Epoxy resins were likewise reacted with xanthate to form viscous media. Alkaligelatinized starch of varying alkali ratio content similarly produced gels with diepoxides. Solids were precipitated from the gels and their compositions were deduced from their elemental contents and infrared spectra.

ON THE TWO-STEP WASH AND WEAR FINISHING OF COTTON FABRICS WITH DIEPOXY COMPOUNDS

Two-step wash and wear finishing of cotton fabrics with diepoxy compounds was investigated. Cotton fabrics were padded with diepoxy compounds and cured under dry conditions in the presence of acidic catalysts (first treatment) and recured under wet conditions in the presence of alkali catalysts by the timing or steaming method (second treatment). The diepoxy compounds studied were as follows.(1) Diepoxy compounds soluble in water: diglycidyl ether (Epoxide I), glycerin diglycidyl ether (Epoxide III), polyethylene diglycidyl ether (Epoxide VI).(2) Diepoxy compounds insoluble in water: ethylene glycol diglycidyl ether (Epoxide II), butanediol diglycidyl ether (Epoxide IV), vinylcyclohexane dioxide (Epoxide VII).Both wet and dry crease recovery angles increased after the second treatment; the steaming method was more effective than the timing method. The high wet crease recovery angles obtained by the second wet curing were durable to repeated laundering. The diepoxy compounds soluble in water were more effective in the crease resistant finishing. The smaller the molecular weight of the diepoxy compounds, the more the improvement of the crease recovery angles. The tearing strength decreased by the second curing, the decrease was smaller however, than that by the first curing.Combination of Epoxide III and conventional cyclic urea derivatives for the two-step treatment was investigated. It was found that dimethyloldihyroxyethyleneurea (DMDHEU) was the most effective coreactant.Ten unsymmetrical sodium-4, 4′-bis-(substituted, 1, 3, 5-triazyl-6)-diaminostilbenedisulfonate 2, 2′ synthesized in the laboratory were compared with a commercial symmetrical whitening agent. The whitening agent was best applied on cotton before the padding of diepoxy compounds.Shirts were made from the cotton fabrics prepared by the two-step Epoxide treatment andthe wearing test was performed for 60 days and 30 launderings.

ON THE REACTION OF COTTON FABRICS WITH EPOXY COMPOUND IN THE PRESENCE OF ACIDIC CATALYSTS

Cotton fabrics were treated with diglycidyl ether (Epoxide I), glycerin diglycidyl ether (Epoxide III), butanediol diglycidyl ether (Epoxide IV), vinylcyclohexene dioxide (Epoxide VII) at low temperatures in the presence of various acidic catalysts and the effects of reaction variables on the degree of reaction and the wrinkle recovery angles were investigated in detail.When the treatment with various Epoxides was carried out at 40°C in the presence of different amount of magnesium fluoroborate for 4min., the dry and wet wrinkle recovery angles increased with increasing concentration of the catalyst and the degree of reaction, and reached the maximum values (dry, 190; wet, 245_??_275°) at the degree of reaction of 40%, and decreased at higher degrees of reaction. The maximum recovery angles (dry, 215_??_260°; wet, 265_??_290°) were obtained at the degree of reaction of 60_??_80% when the treatment was carried out at 60°C, and the maximum values (dry, 225_??_300°; wet, 295_??_300°) were obtained at the degree of reaction of 75_??_80% when the treatment was done at 80°C. Epoxide I gave higher dry wrinkle recovery angles than other Epoxides did. The treatment at lower temperatures improved the wet recovery much more than the dry recovery. The treatment at higher temperatures improved both dry and wet recoveries.Solubility and dyeability tests on the treated fabrics indicated the formation of effective crosslinks during the treatment.