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Effect of acrylate chemistry on human health.

OBJECTIVES: The prospective cohort study of 1992-1999 describes the effect of occupational exposure to chemical substances in the production of acrylic acid, acrylic acid esters and acrylate dispersions at the various workplaces of one chemical plant. METHODS: Exposure to selected chemicals (acrylonitrile, n-butanol, butyl acrylate, ethyl acrylate, methyl acrylate, methyl methacrylate, toluene, and styrene) was determined by personal passive dosimetry (GC/MS method). The annual examinations included general health, by guided interview, a general medical examination, hematological and biochemical examinations, examination of the parameters of serum immunity and selected tumor markers, and spirometry. The authors also repeatedly performed cytogenetic analysis of human peripheral lymphocytes. RESULTS: The authors followed a group of 120 employees (60 exposed, 60 controls), mean age 40+/-8 years in both groups, with average period of exposure to chemicals (exposed group) 13+/-5 years. The measured concentrations of chemicals in the working atmosphere were generally low; maximum allowable concentrations (MAC) values or suggested limits of certain chemicals were occasionally exceeded (most frequently for butyl acrylate). The results of the examination of the workers over the 8 years have not revealed any marked differences between the exposed and control groups that could be attributable solely to the acrylate exposure. CONCLUSIONS: Exposure to chemical substances at the workplace was relatively low, the limits being exceeded only sporadically (each such case was investigated at the workplace), and the level of exposure continues to decrease gradually over the years. Considering the fact that the exposed individuals are expected to work for 23 additional years on average, we feel that long-term monitoring of selected health-related parameters, not including tumor markers, appears desirable. The examination of tumor markers has not contributed to the problem evaluation for a number of false-positive results.

Acrylates↗

Characterisation of UV-cured acrylate networks by means of hydrolysis followed by aqueous size-exclusion combined with reversed-phase chromatography.

UV-cured networks prepared from mixtures of di-functional (polyethylene-glycol di-acrylate) and mono-functional (2-ethylhexyl acrylate) acrylates were analysed after hydrolysis, by aqueous size-exclusion chromatography coupled to on-line reversed-phase liquid-chromatography. The mean network density and the fraction of dangling chain ends of these networks were varied by changing the concentration of mono-functional acrylate. The amount and the molar-mass distribution of the polyethylene-glycol chains between cross-links (M(XL)) and polyacrylic acid (PAA) backbone chains (the so-called kinetic chain length (kcl)) in the different acrylate networks were determined quantitatively. The molar-mass distribution of kcl revealed an almost linear dependence on the concentration of mono-functional acrylate. Analysis of the starting materials showed a significant concentration of mono-functional polyethylene-glycol acrylate. In combination with the analysis of the extractables of the UV-cured networks (polymers not attached to the network, impurities that originate from the photo-initiator and unreacted monomers), more insight in the total network structure was obtained. It was shown that the UV-cured networks contain only small fractions of residual compounds. With these results, the chemical network structure for the different UV-cured acrylate polymers was expressed in network parameters such as the number of PAA units which are cross-linked, the degree of cross-linking, and the network density, which is the molar concentration of effective network chains between cross-links per volume of the polymers. The mean molar mass of chains between chemical network junctions (M(C)) was calculated and compared with results obtained from solid-state NMR and DMA. The mean molar mass of chains between network junctions as determined by these methods was similar.

Acrylates↗

Comparison of the stability of 1-piece and 3-piece acrylic intraocular lenses in the lens capsule.

PURPOSE: To compare the degrees of intraocular lens (IOL) decentration, tilt, and longitudinal movement; the refractive change; and anterior capsule contraction after cataract surgery between eyes with a 1-piece acrylic IOL with soft acrylic loops and eyes with a 3-piece acrylic IOL with rigid poly(methyl methacrylate) loops. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: Fifty-six patients had implantation of a 1-piece acrylic IOL in 1 eye and a 3-piece acrylic IOL in the fellow eye. The degree of IOL decentration and tilt, the anterior chamber depth (ACD), and the area of anterior capsule opening were measured using Scheimpflug videophotography 3 days and 1, 3, and 6 months postoperatively. The postoperative refractive status was also examined. RESULTS: The mean degrees of decentration and tilt in the 1-piece IOL group were similar to those in the 3-piece IOL group throughout the follow-up. The ACD did not change after surgery in the 1-piece group but showed significant shallowing in the 3-piece group (P < .0001). The spherical equivalent (SE) did not change in the 1-piece group, while the SE had a significant myopic shift of approximately 0.4 diopter in the 3-piece group. The percentage of anterior capsule contraction was similar between the groups. CONCLUSIONS: The degree of IOL decentration and tilt and percentage of anterior capsule contraction in eyes with a 1-piece acrylic IOL with soft acrylic loops were similar to those in eyes with a 3-piece acrylic IOL. The longitudinal movement of the 1-piece IOL was less than the movement of the 3-piece IOL, resulting in less postoperative myopic shift.

Acrylic Resins↗

Effect of microwave sterilization and water storage on the Vickers hardness of acrylic resin denture teeth.

STATEMENT OF PROBLEM: Acrylic resin denture teeth soften upon immersion in water, and the heating generated during microwave sterilization may enhance this process. PURPOSE: Six brands of acrylic resin denture teeth were investigated with respect to the effect of microwave sterilization and water immersion on Vickers hardness (VHN). MATERIAL AND METHODS: The acrylic resin denture teeth (Dentron [D], Vipi Dent Plus [V], Postaris [P], Biolux [B], Trilux [T], and Artiplus [A]) were embedded in heat-polymerized acrylic resin within polyvinylchloride tubes. For each brand, the occlusal surfaces of 32 identical acrylic resin denture posterior teeth were ground flat with 1500-grit silicon carbide paper and polished on a wet polishing wheel with a slurry of tin oxide. Hardness tests were performed after polishing (control group, C), after polishing followed by 2 cycles of microwave sterilization at 650 W for 6 minutes (MwS group), after polishing followed by 90-day immersion in water (90-day Wim group), and after polishing followed by 90-day storage in water and 2 cycles of microwave sterilization (90-day Wim + MwS group). For each specimen, 8 hardness measurements were made and the mean was calculated. Data were analyzed with a 2-way analysis of variance followed by the Bonferroni procedure to determine any significance between pairs of mean values (alpha=.01). RESULTS: Microwave sterilization of specimens significantly decreased (P <.001) the hardness of the acrylic resin denture tooth specimens P (17.8 to 16.6 VHN), V (18.3 to 15.8 VHN), T (17.4 to 15.3 VHN), B (16.8 to 15.7 VHN), and A (17.3 to 15.7 VHN). For all acrylic resin denture teeth, no significant differences in hardness were found between the groups MwS, 90-day Wim, and 90-day Wim + MwS, with the exception of the 90-day Wim + MwS tooth A specimens (14.4 VHN), which demonstrated significant lower mean values (P <.001) than the 90-day Wim (15.8 VHN) and MwS (15.7 VHN) specimens. CONCLUSIONS: For specimens immersed in water for 90 days, 2 cycles of microwave sterilization had no effect on the hardness of most of the acrylic resin denture teeth.

Acrylic Resins↗

Metabolism of acrylate esters in rat tissue homogenates.

Methyl, ethyl and butyl acrylate were hydrolyzed to acrylic acid in rat liver, kidney and lung homogenates. The rates of hydrolysis of the various esters in these in vitro studies were comparable; hydrolysis rates were approximately 20 times higher in liver homogenates than in kidney or lung homogenates. The esters also disappeared rapidly when added to blood in vitro. However, the disappearance in blood was not associated with the appearance of acrylic acid. Ethyl acrylate was found to react spontaneously with GSH in vitro and this reaction was catalyzed greatly by enzymes in 100 000 x g liver supernatant. Acrylic acid did not react with GSH in vitro. Ethyl acrylate, but not acrylic acid, depletes non-protein sulfhydryls when added to blood in vitro. Thus, the disappearance of acrylate esters in blood in vitro could be due at least in part to binding with non-protein sulfhydryls in red blood cells rather than to hydrolysis.

Acrylates↗

Structure-activity relationships in the hydrolysis of acrylate and methacrylate esters by carboxylesterase in vitro.

Acrylate esters are important chemicals in the plastics industry, whose toxicity is theorized to involve alkylation of critical cellular nucleophiles via the Michael addition. Carboxylesterase-mediated hydrolysis of acrylates may be a detoxification mechanism as the unsaturated acid produced is not electrophilic under physiological conditions. Using purified porcine liver carboxylesterase, the enzymatic hydrolysis of several acrylate esters was characterized to determine Km and Vmax values for each ester. The Km (microM) and Vmax (nmol/min) values observed for ethyl acrylate were 134 +/- 16 (S.D.) and 8.9 +/- 2.0, respectively. While the Km for ethyl methacrylate was not significantly different, the Vmax 5.5 +/- 2.5, was significantly lower compared with the corresponding value for ethyl acrylate. The Km and Vmax for butyl acrylate were 33.3 +/- 8.5 microM and 1.49 +/- 0.83 nmol/min, respectively, and the corresponding values for its alpha-methyl analog were not significantly different. The Km and Vmax for tetraethyleneglycol dimethacrylate were 39 +/- 15 microM and 2.9 +/- 1.0 nmol/min, respectively. The Vmax for ethyleneglycol dimethacrylate, 6.9 +/- 2.4 nmol/min, was significantly higher than that of the larger bifunctional ester tetraethyleneglycol dimethacrylate, but the Km was not significantly different. These results indicate that alpha-methyl substitution appears to have a minor effect in the enzymatic hydrolysis of acrylates, and suggest that the relative toxicity of acrylates is not due to differences in carboxylesterase-mediated hydrolysis.

Acrylates↗

Chemistry and biological activities of N,N-dimethylaminoethyl acrylate, a choline acetyltransferase inhibitor.

N,N-Dimethylaminoethyl acrylate (acryl-DMA) was synthesized as a tertiary nitrogen choline acetyltransferase (ChAc) inhibitor which would be able to penetrate biological membranes to inhibit ChAc in the nerve terminal. The synthesis from dimethylaminoethanol and acrylyl chloride was described and the hydration with times in an aqueous medium measured by NMR spectroscopy was presented. The autohydrolysis in water was found to be 1.75 x 10(-8) mol/min at pH 7.4 and 5.0 mM concentration. The enzymatic hydrolysis was unaffected by cholinesterases. Acryl-DMA was capable of inhibiting ChAc extracted from rat brain with I50 of 5.02 x 10(-4) M. The inhibition was reversible and displayed uncompetitive kinetics with respect to both substrates, choline and acetyl-CoA. Neither the hydrolysis nor the hydration products of acryl-DMA could inhibit ChAc. Although acryl-DMA was hydrated rapidly and completely within 1 hr at high pH (9.0), the time course of inhibition ability of acryl-DMA in aqueous medium at physiological pH was found to decrease rather slowly and by 36% in 1 hr, indicating that acryl-DMA can survive from hydration at physiological pH. Acryl-DMA was also tested for its ability to block electrically induced muscle contractions in both isolated skeletal and smooth nerve-muscle preparations. The ED50's obtained were less than 5 x 10(-4) M in both cases.

Acetyltransferases↗

Color stability of heat-activated and chemically activated fluid resin acrylics.

PURPOSE: Heat- and chemically activated acrylics processed by compression molding or fluid resin matrix techniques for fabrication of partial dentures were evaluated for color stability by reflection spectrophotometry after accelerated aging. MATERIALS AND METHODS: Samples of heat-activated (L199, PDON, SB) and chemically activated (PR, PVAR, SC) denture base acrylics were polymerized according to manufacturers' instructions. Samples were aged in an artificial aging chamber, and color was measured by CIE L*a*b* on a reflection spectrophotometer at baseline and after each of three aging cycles. RESULTS: At 450 kJ/m2, color changes of two chemically activated acrylics (PR and SC) were perceptible. PR became less red, whereas SC became darker and more yellow. The most color-stable acrylics were a heat-activated resin (SB) and one chemically activated acrylic (PVAR). CONCLUSIONS: The three heat-activated acrylics tested were more color-stable than two of the chemically activated acrylics, but one chemically activated acrylic (PVAR) recommended for a fluid resin matrix technique was color-stable.

Acrylic Resins↗

Contact dermatitis from acrylate and methacrylate compounds in Lowicryl embedding media for electron microscopy.

This report is about occupational contact dermatitis found in 3 out of 6 workers of a chemistry laboratory using Lowicryl embedding media, which contain (meth)acrylate monomer mixtures of known composition. The notation (meth)acrylates is used to refer to both acrylates and methacrylates. (Meth)acrylate monomers will polymerize in the absence of oxygen when induced by metal ions, peroxides, heat or ultraviolet light. The monomers are of low viscosity and remain in the liquid state at temperatures far below 0 degree C. The volatile compounds, some of which exhibit a most pungent odour, have a tendency to penetrate all tissue and to permeate into the finest fissures, a property which makes them suitable as sealants, glues, embedding material, etc. This and their toxicity may represent a danger to the health of individuals who need to work with them, especially if no precautions are taken. We show with patch testing that one patient reacted strongly to the compound 2-hydroxyethyl acrylate at the dilutions tested (0.5 and 1% v/v), but not at all to 10 other (meth)acrylates. In the same test, 3 volunteer controls were negative to 2-hydroxyethyl acrylate. We demonstrate that at maximum working concentration, 2-hydroxyethyl acrylate penetrates both latex and vinyl gloves and elicits irritant/allergic reactions on the patient and irritant reactions on a control. Finally, we discuss the necessary protective measures.

Acrylic Resins↗

Chelation in metal intoxication. XXIX: Alpha-mercapto-beta-aryl acrylic acids as antidotes to mercury (II) toxicity.

alpha-Mercapto-beta-(2-furyl) acrylic acid (MFA), alpha-mercapto-beta-(phenyl) acrylic acid (MPA), alpha-mercapto-beta-(2-hydroxyphenyl) acrylic acid (MHA), alpha-mercapto-beta-(4-methoxyphenyl) acrylic acid (MMA), beta-1,2-phenylene di-alpha-mercapto acrylic acid (1, 2-PDMA) and beta-1, 4-phenylene di-alpha-mercapto acrylic acid (1, 4-PDMA) enhanced faecal excretion and reduced liver, spleen and blood burden of inorganic mercury when administered (0.5 m mol/kg, in two split doses) 24 hr after Hg (II) (1 mg/kg) in rats. MFA, MPA, MHA, and MMA were also effective in lowering renal Hg mainly from the cytosol, without any significant increase in urinary excretion of Hg. The results indicate that all the mono-mercapto acrylic acids including MFA were more effective than di-mercapto acrylic acids and act through the mechanism characteristic of thiol chelators, that is, mobilization of Hg as their complexes, contrary to the reported observation that MFA acts through the induction of metallothionein.

Acrylates↗

Nuclear magnetic resonance analysis of [1-13C]dimethylsulfoniopropionate (DMSP) and [1-13C]acrylate metabolism by a DMSP lyase-producing marine isolate of the alpha-subclass of Proteobacteria.

The prominence of the alpha-subclass of Proteobacteria in the marine bacterioplankton community and their role in dimethylsulfide (DMS) production has prompted a detailed examination of dimethylsulfoniopropionate (DMSP) metabolism in a representative isolate of this phylotype, strain LFR. [1-(13)C]DMSP was synthesized, and its metabolism and that of its cleavage product, [1-(13)C]acrylate, were studied using nuclear magnetic resonance (NMR) spectroscopy. [1-(13)C]DMSP additions resulted in the intracellular accumulation and then disappearance of both [1-(13)C]DMSP and [1-(13)C]beta-hydroxypropionate ([1-(13)C]beta-HP), a degradation product. Acrylate, the immediate product of DMSP cleavage, apparently did not accumulate to high enough levels to be detected, suggesting that it was rapidly beta-hydroxylated upon formation. When [1-(13)C]acrylate was added to cell suspensions of strain LFR it was metabolized to [1-(13)C]beta-HP extracellularly, where it first accumulated and was then taken up in the cytosol where it subsequently disappeared, indicating that it was directly decarboxylated. These results were interpreted to mean that DMSP was taken up and metabolized by an intracellular DMSP lyase and acrylase, while added acrylate was beta-hydroxylated on (or near) the cell surface to beta-HP, which accumulated briefly and was then taken up by cells. Growth on acrylate (versus that on glucose) stimulated the rate of acrylate metabolism eightfold, indicating that it acted as an inducer of acrylase activity. DMSP, acrylate, and beta-HP all induced DMSP lyase activity. A putative model is presented that best fits the experimental data regarding the pathway of DMSP and acrylate metabolism in the alpha-proteobacterium, strain LFR.

Acrylates↗

Nd:YAG capsulotomy rates after use of the AcrySof acrylic three piece and one piece intraocular lenses.

BACKGROUND/AIM: Acrylic lens size and shape may influence the rate of posterior capsule opacification (PCO) and need for Nd:YAG capsulotomy. The aim of this study is to compare the Nd:YAG capsulotomy rate of the three piece acrylic/PMMA AcrySof MA series lens with the one piece acrylic AcrySof SA series lens. METHODS: 434 eyes of 329 patients who had cataract extraction and implantation of one of four types of intraocular lenses (IOLs) were evaluated for rate of Nd:YAG capsulotomy. 176 eyes received the acrylic AcrySof MA30AC IOL, 71 eyes the acrylic AcrySof MA60AC IOL, 45 eyes the acrylic AcrySof SA30AL IOL, and 142 eyes the acrylic AcrySof SA60AT IOL. RESULTS: The rates of Nd:YAG capsulotomy with the three piece IOL (MA30AC/MA60AC) and the one piece IOL (SA30AL/SA60AT) were 1.2% and 2.1% at 6 months, 2.8% and 5.9% at 12 months, and 3.6% and 7.5% at 24 months, respectively. The incidence of Nd:YAG capsulotomy was higher in patients who received the one piece IOL (p=0.01, log rank test). There was no difference in Nd:YAG capsulotomy rates when comparing lens optic size, age, sex, history of pars plana vitrectomy, and diabetes mellitus. CONCLUSIONS: This study shows a greater incidence of Nd:YAG capsulotomy in patients who receive one piece acrylic AcrySof lenses when compared to those who receive three piece acrylic AcrySof lenses.

Acrylic Resins↗

Comparison of the fracture resistance of six denture base acrylic resins.

Fracture strength of denture base resins is of great concern, and many approaches have been used to strengthen acrylic resin dentures. Fracture resistance of six commercially available acrylic resin denture base materials were compared, through impact and transverse strength tests. Three rapid heat-polymerised resins (QC 20, Meliodent and Trevalon), two high-impact strength resins (Trevalon Hi and Lucitone 199) and a strengthened injection-moulded acrylic resin (SR Ivocap plus) were included in the study. Twenty acrylic resin test specimens were fabricated from each resin. For impact strength test, ten notched specimens were tested in a Charpy-type impact tester. The other ten specimens were used for transverse strength tests, deflection and modulus of elasticity values were also determined, which were assessed with three-point bending tests using an Universal Testing Machine. Impact test values showed significant differences among acrylic resins (F= 4.817 p = 0.0). SR Ivocap resin showed the highest impact strength values, followed by Trevalon Hi and Lucitone 199. The transverse strength test values were not significant when six acrylic resins were compared (F= 1.705 p = 0.151). High-impact resins can be recommended to increase the impact strength of denture base. If the cause of fracture is mechanical or anatomical, strengthened acrylic resins and conventional acrylic resins have similar fracture resistance.

Acrylic Resins↗

Pathology findings with acrylic implants.

We report the pathological findings in cases of acrylic implants obtained by direct intratumoral injection of polymethyl-methacrylate (PMMA) and N-butyl-cyano-acrylate (NBCA). Direct intratumoral injection of acrylic implants was performed for a variety of primary and secondary bone lesions. These types of treatments have been used at our institution in the last 4 years for 40 vertebroplasty (PMMA) procedures and for nine bone lesions of other locations (PMMA, NBCA). Postmortem histology became available for 1 case of PMMA and for 5 cases with NBCA intratumoral acrylic implants. The pathological findings associated with PMMA and NBCA were evaluated and compared. PMMA exhibited a macroscopic and microscopic rim of tumor necrosis, 6 months after implantation. NBCA exhibited compressive effects on the nearby tumor tissue, however, without signs of significant necrosis outside the acrylic tumor cast. Tumor captured inside the acrylic cast showed extensive to near complete necrosis. Acrylic implants may lead to necrosis when injected directly in tumors. The necrotizing effect may extend beyond the limits of an implant in the case of PMMA. Such an extended effect of PMMA, when compared with NBCA, may be due to the variable toxicity of acrylic implants, including the different degrees of the exothermic reaction during polymerization.

Adenocarcinoma↗

Acrylic spinal fusion. A 20-year clinical series and technical note.

Methyl methacrylate (acrylic) was used in fusion techniques in 82 patients, most of whom had metastatic disease, between 1959 and 1979. In all cases the acrylic was used to supplement stabilization with Meurig-Williams stainless steel plates or with wire. In cases involving a decompressive laminectomy and excisional biopsy (radical resection of a tumor mass) that required posterior stabilization, acrylic helped to achieve rapid fusion with excellent results. The series included one anterior fusion with acrylic and nine atlantoaxial fusions in patients without tumors. Strict guidelines for selection of patients are outlined. The advantage of acrylic over bone fusion in selected patients is discussed. Careful follow-up studies including autopsy examinations are included. The technique of the use of acrylic is outlined. There was no case of late instability. There was one instance of infection in a patient who was immunodeficient and in whom a combination acrylic and bone fusion was performed. Tissue reaction to the acrylic in autopsy specimens is discussed.

Adolescent↗

Cross-reactivity among epoxy acrylates and bisphenol F epoxy resins in patients with bisphenol A epoxy resin sensitivity.

OBJECTIVE: The study's objective was 2-fold: first, to evaluate the potential cross-reactivity between Bis-A epoxy resins and epoxy acrylates and second, to study the cross reactivity between Bis-A epoxy resins and newer Bis-F epoxy resins in patients with allergic contact dermatitis to epoxy resins and had positive patch test to the standard epoxy resin based on bisphenol A. METHODS: Forty-one patients were patch tested to 23 chemicals including epoxy acrylates, Bis-A epoxy resins, and Bis-F epoxy resins, as well as reactive diluents and nonbisphenol epoxy resins. Questions concerning exposure to epoxy resins, occupational history, and problems with dental work were completed. RESULTS: All patients included in the study had positive reactions to the standard Bis-A epoxy resin. Twenty percent (8 of 41) of the patients reacted to at least one of the epoxy acrylates; the most common reaction was to Bis-GMA. Five of 8 patients who reacted to the epoxy acrylates had dental work, but only one patient had problems from her dental work. Six of 8 patients (75%) who reacted to epoxy resins and epoxy acrylates did not react to aliphatic acrylates. Thirty-two percent (13 of 41) reacted to tosylamide epoxy resin, and none reacted to triglycidyl isocyanurate resin. In addition, all patients (100%) had positive reactions to at least one of the Bis-F epoxy resins that were tested. CONCLUSIONS: Most patients with sensitivity to Bis-A epoxy resins do not cross-react with epoxy acrylates. Patients with positive patch test reactions to epoxy acrylates used in dentistry usually do not have symptoms from their dental work. To our knowledge, this is the largest series of patients with sensitivity to the standard Bis-A epoxy resin that have been patch tested with the more recently introduced Bis-F epoxy resins. There is significant cross-reactivity between Bis-A and Bis-F epoxy resins, which can be explained by their structural similarity.

Adult↗

Allergic contact dermatitis to artificial fingernails prepared from UV light-cured acrylates.

BACKGROUND: Contact dermatitis from artificial nails made from self-curing acrylic resins is occasionally reported. Recently, UV light-cured products introducing new acrylics have become available. OBJECTIVE: Our purpose was to identify relevant allergens in commercial light-curing products by patch tests and to evaluate the efficacy of "hypoallergenic" products by inclusion into the test series. METHODS: Patients wearing photobonded acrylic nails who had perionychial and subonychial eczema were patch tested with an acrylate battery and "hypoallergenic" commercial products. RESULTS: Triethyleneglycol dimethacrylate, hydroxyfunctional methacrylates, and (meth)-acrylated urethanes proved to be relevant allergens in photobonded nail preparations. Methacrylated epoxy resin sensitization was not observed. All "hypoallergenic" products provoked positive reactions. CONCLUSION: The omission of irritant methacrylic acid in UV-curable products does not reduce the high sensitizing potential of new acrylates. In contrast to the manufacturers' declarations, all "hypoallergenic" products continue to include acrylate functional monomers and therefore continue to cause allergic sensitization.

Acrylates↗

The sensitizing capacity of multifunctional acrylates in the guinea pig.

The multifunctional acrylates used in ultraviolet (UV) curable resins act as cross-linkers and "diluents". They are usually based on di(meth)acrylate esters of dialcohols or tri- and tetra-acrylate esters of polyalcohols. In UV-curable coatings, the most commonly used are pentaerythritol triacrylate (PETA), trimethylolpropane triacrylate (TMPTA) and 1,6-hexanediol diacrylate (HDDA). In other uses, such as dental composite resin materials, the dimethacrylic monomers based on n-ethylene glycol are the most useful. The sensitizing capacity of various multifunctional acrylates and their cross-reactivity pattern have been investigated with the guinea pig maximization test. The tests show that BUDA (1,4-butanediol diacrylate) and HDDA are moderate to strong sensitizers and that they probably cross-react with each other. The n-ethylene glycol diacrylates and methacrylates tested are weak or non-sensitizers. Tripropylene glycol diacrylate (TPGDA) is a moderate and neopentyl glycol diacrylate (NPGDA) a strong sensitizer, whereas neopentyl glycol dimethacrylate is a non-sensitizer. The commercial PETA is a mixture of pentaerythritol tri- and tetra-acrylate (PETA-3 and PETA-4). PETA-3 is a much stronger sensitizer than PETA-4. Simultaneous reactions were seen between PETA-3, PETA-4 and TMPTA. The oligotriacrylate OTA 480 is a moderate sensitizer, but no concomitant reactions were seen with PETA-3, PETA-4 or TMPTA. Of the multifunctional acrylates tested, the di- and triacrylic compounds should be regarded as potent sensitizers. The methacrylated multifunctional acrylic compounds are weak or non-sensitizers.

Acrylates↗