Influence of the base and diluent methacrylate monomers on the polymerization stress and its determinants

The aim of this study was to evaluate the effect of the association between bisphenol‐A diglycidyl dimethacrylate (BisGMA) or its ethoxylated version (BisEMA) with diluents derived from the ethylene glycol dimethacrylate (EGDMA), with increasing number of ethylene glycol units (1: EGDMA, 2: DEGDMA, 3: TEGDMA, or 4: TETGDMA), or trimethylol propane trimethacrylate (TMPTMA) or 1,10‐decanediol dimethacrylate (D₃MA) on polymerization stress, volumetric shrinkage, degree of conversion, maximum rate of polymerization (Rp_max), and elastic modulus of experimental composites. BisGMA containing formulations presented lower shrinkage and stress but higher modulus and Rp_max than those containing BisEMA. TMPTMA presented the lowest stress among all diluents, as a result of lower conversion. EGDMA, DEGDMA, TEGDMA, and TETGDMA presented similar polymerization stress which was higher than the stress presented by D₃MA and TMPTMA. D₃MA presented similar conversion when copolymerized with both base monomers. The other diluents presented higher conversion when associated with BisEMA. EGDMA showed similar shrinkage compared with DEGDMA and higher than the other diluents. The lower conversion achieved by TMPTMA did not jeopardize its elastic modulus, similar to the other diluents. Despite the similar conversion presented by D₃MA in comparison with EGDMA and DEGDMA, its lower elastic modulus may limit its use. Rather than proposing new materials, this study provides a systematic evaluation of off the shelf monomers and their effects on stress development, as highlighted by the analysis of conversion, shrinkage and modulus, to aid the optimization of commercially available materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Photopolymerizable multifunctional monomers and their evaluation as reactive Bis‐GMA eluents

Bis‐GMA {2,2‐bis[4‐(2′‐hydroxy‐3′‐methacryloyloxy‐propoxy)‐phenyl]‐propane}, TEGDMA <2‐{2‐[2‐(2‐methylprop‐2‐enoyloxy)ethoxy]ethoxy}ethyl‐2‐methylprop‐2‐enoate>, and methyl methacrylate (MMA) are some of the most commonly used monomers in the field of restorative dentistry. These compounds are characterized by having one or two terminal double bonds. Besides the effort to synthesize new monomers, several problems still affect the clinical behavior of contemporary dental materials. In this work, two monomers with three terminal double bonds, 5A13DA and 5A13DMA, were synthesized. Both monomers were used to completely replace TEGDMA as reactive diluent of photopolymerizable dental resin composites containing Bis‐GMA. The effects of 5A13DA and 5A13DMA on flexural properties, double bond conversion, water sorption, solubility, and polymerization shrinkage were evaluated. In addition, both monomers were evaluated as crosslinking agents for methylmethacrylate, resulting in copolymers with enhanced thermal stability. The results obtained suggest that newly synthesized monomers are potential substitutes for TEGDMA in the formulation of dental composites, providing 50% lower volumetric shrinkage than the composite resin used as control and adequate mechanical properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46240.     

Synthesis of novel antibacterial monomers (UDMQA) and their potential application in dental resin

To prepare antibacterial dental resin, a series of novel urethane dimethacrylates quaternary ammonium methacrylate monomers (UDMQAs) with different substituted alkyl chain length were synthesized, and their structures were confirmed by FTIR and ¹H‐NMR spectra. The obtained UDMQAs were used to replace 2,2‐Bis[4‐(2‐hydroxy‐3‐methacryloyloxypropyl)‐phenyl]propane (Bis‐GMA) totally as base monomers of dental resin and mixed with Tri‐ethyleneglycol dimethacrylate (TEGDMA) at the mass ratio of 50/50. The properties of these prepared resins like antibacterial activity, double bond conversion (DC), polymerization shrinkage, flexural strength (FS), and modulus (FM), water sorption and sol fraction were investigated. The most commonly used dental resin Bis‐GMA/TEGDMA (50wt/50wt) was chosen as a reference. The results showed that UDMQAs could endow dental resin with antibacterial activity. Compared with Bis‐GMA‐based dental resin, UDMQAs‐based resin had the same or higher DC, lower polymerization shrinkage, lower flexural strength and modulus, and higher water sorption and sol fraction. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Evaluation of monomers derived from resorcinol as eluents of bisphenol A glycidyl dimethacrylate for the formulation of dental composite resins

The objective of this work was to synthesize two bio-based monomers, using the resorcinol as raw material, and its effect as bisphenol A glycidyl dimethacrylate (Bis-GMA) eluents on different chemical–physical and biological properties of experimental photopolymerizable composite resins. The acrylic 1,3-phenylen diacrylic (1,3-FDA) and methacrylic 1,3-phenylen dimethacrylic (1,3-FDMA) monomers were synthesized and fully characterized through FTIR and ¹H-NMR spectroscopies. Experimental photopolimerizable composites were formulated using Bis-GMA/1,3-FDA or Bis-GMA/1,3-FDMA as organic matrix. The materials were compared with a Bis-GMA/TEGDMA resin-based composite used as control. Polymerization kinetics was evaluated by means of FTIR spectroscopy. Polymerization stress was directly measured through a polymerization stress tester. The cell viability of the composites was evaluated using the MTT assay. One-way analysis of variance and Tukey's test were used for statistical analysis. The materials formulated with the 1,3-FDA monomer showed higher Rp_max values and lower polymerization stress values (p < 0.05), while the flexural strength, water sorption, and solubility remained similar to the TEGDMA composite. Conversely, the materials formulated with the 1,3-FDMA monomer showed a lower degree of conversion and statistically lower flexural strength (p < 0.05). All materials exhibited a cellular viability close to 100%. Concerning the study conditions, the acrylic 1,3-FDA monomer could be considered an alternative to TEGDMA in the formulation of photopolymerizable dental composite resins. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48576.     

Properties of 2,2‐Bis[p‐(2′‐hydroxy‐3′‐methacryloxy propoxy)phenyl]propane/Isobornyl (Meth)acrylate copolymers

Isobornyl acrylate (IBOA) and isobornyl methacrylate (IBOMA) were used to replace triethylene glycol dimethacrylate (TEGDMA) as reactive diluents in dental restorative materials. Photopolymerization behaviors of mixtures of IBO(M)A and 2,2‐bis[p‐(2′‐hydroxy‐3′‐methacryloxy propoxy)phenyl]propane (Bis‐GMA) were investigated by Fourier transform infrared spectroscopy. The degree of conversion, volume shrinkage, contact angle, water sorption, water solubility, flexural strength, and modulus values of the Bis‐GMA/IBO(M)A formulations were measured and compared with those of a Bis‐GMA/TEGDMA formulation. The results illustrate that the degree of conversion, volume shrinkage, contact angle, water sorption, flexural strength, and modulus values of the Bis‐GMA/IBO(M)A systems were all lower than those of the Bis‐GMA/TEGDMA system; the water solubility values of the Bis‐GMA/IBO(M)A systems were higher than that of the Bis‐GMA/TEGDMA system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Photopolymerizable bisallylcarbonate and bisacrylic monomers useful in the formulation of dental composite resins and in the crosslinking of methyl methacrylate

Two new bisallylic monomers [allyl p‐allyl carbonate benzoate (ApACBz) and 1,4‐phenylenbis(methylene)diallyl carbonate (1,4‐FMDAC)] and one bisacrylic monomer [1,4‐bis(acryloyloxymethyl)benzene (1,4‐BAMB)] were synthesized and used as crosslinking agents of methyl methacrylate (MMA) at different mass ratios (10, 20, 40, and 50%). All of the obtained copolymers showed improved thermal stability in comparison with that of the MMA homopolymer. Also, ApACBz and 1,4‐FMDAC were used as bisphenol A glycidyl methacrylate (Bis‐GMA) eluents to prepare dental resin composites. When compared to the control, the Bis‐GMA–new eluent composites had a higher double‐bond conversion, a higher solubility (p < 0.05) and a lower flexural strength (p < 0.05), whereas the elastic modulus and water sorption values were not statistically different (p > 0.05). The 1,4‐FMDAC and ApACBz monomers are promising eluents of Bis‐GMA for the preparation of dental composites with high degrees of conversion. In addition, the ApACBz, 1,4‐FMDAC, and 1,4‐BAMB monomers are potentially useful crosslinking agents when polymer networks of poly(methyl methacrylate) with a high thermal stability are desired. The application‐oriented tests of the monomers in dental composite formulations showed a sufficient storage stability, high photocuring activity, excellent crosslinking of MMA, and good thermal and mechanical properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42920.     

Synthesis of two PET waste derived bisacrylic and bisallylic monomers and their potential use as crosslinking agents and dental resin composites

Two novel bifunctional monomers obtained from PET waste glycolisis are reported. Bis(2‐(acryloyloxy)ethyl) terephthalate and bis(2‐(((allyloxy)carbonyl)oxy)ethyl) terephthalate (BACET) monomers were obtained from bis(hydroxyethyl) terephthalate derived from PET waste and acryloyl chloride and allyl chloroformate, respectively. The monomers were characterized by FTIR and ¹H‐NMR spectroscopies. They were evaluated as crossslinking agents for acrylic acid (AA) and methacrylic (MA) acids using thermally initiated polymerization. The obtained copolymers showed higher thermal stability than the acrylic homopolymers. They were also tested for dental formulations as Bis‐GMA substitutes in heat curing resin composites. In spite of its lower reactivity, only BACET was able to substitute Bis‐GMA, due to its high solubility in the TEGDMA comonomer. Resin formulations containing nanosized silica and the mixture Bis‐GMA/TEGDMA or BACET/TEGDMA were prepared in order to compare physical and chemical properties. Water sorption, solubility, and flexural strength were found statistically similar for both formulations. However, flexural modulus was lower and double bond conversion was higher for the BACET resin, which could make it appropriate for its potential use in dental resin composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41487.     

Dental restorative composites containing methacrylic spiroorthocarbonate monomers as antishrinking matrixes

In this work, the synthesis of two new antishrinking methacrylic monomers of spiroorthocarbonate type, SOC-IP-UDMA and SOC-UDMA, is discussed, along with studies of their performance as polymeric matrix in dental composites. The monomers were photoactive with components of a conventional resin composite. In order to study the photocuring kinetics of these SOC monomers, a real-time test was performed using FTIR spectroscopy. It was found that SOCs promoted higher double bond conversions (DC) than conventional methacrylic monomer bis-GMA (48%), reaching a DC value of 68% for SOC-UDMA and 75% for SOC-IP-UDMA. The shrinkage stress that accompanies curing of dental composites was measured by a universal testing machine. These new monomer SOCs are capable of reducing the shrinkage up to 51.1% and 27.7% for both methacrylic monomers when they were compared with bis-GMA as control. Also, a dynamical mechanical analysis was conducted on the dental composites, obtaining a higher modulus and a range of T _g values from 80 to 100 °C. Others parameters like flexural properties, solubility, and sorption water were determined, obtaining values better than or equal to the parameters established by the standard ISO 4049. These monomers can be considered as alternative matrixes to replace bis - GMA in dental composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47114.     

Effects of composition and extrusion parameters on the morphological development and rheological properties of PP/PC blends. Co-continuity investigation

In this work, a new dimethacrylate monomer named ??,????-Bis(4-(2??-hydroxy- 3??methacryloyloxy-propoxy)-3,5-dimethylphenyl)-1,4-diisopropyl-benzene (??,????-BHMPDDB) was synthesized to replace 2,2-bis[4-(2??-hydroxy-3??-methacryloyloxy-propoxy)-phenyl]propane (Bis-GMA) as one component of dental composite materials. The structures of ??,????-BHMPDDB and its intermediate product ??,????-Bis(4-oxiranylmethoxy-3,5-dimethylphenyl)-1,4-diisopropylbenzene (??,????-BODDB) were confirmed by FT-IR, ¹H-NMR, and elemental analysis. ??,????-BHMPDDB was mixed with TEGDMA to form a new dental resin, and double bond conversion, polymerization shrinkage, contact angle, water sorption and solubility, flexural strength and modulus before and after water immersion of this new dental resin were studied. Compared with the commonly used Bis-GMA/TEGDMA dental resin, ??,????-BHMPDDB/TEGDMA had higher double bond conversion (60.5?±?0.3?%), lower polymerization shrinkage (5.6?%), and comparable flexural strength before water immersion (94.1?±?3.9?MPa), which made ??,????-BHMPDDB/TEGDMA having potential to replace Bis-GMA/TEGDMA as matrix phase of dental composites materials. However, ??,????-BHMPDDB/TEGDMA also had drawbacks, such as higher water sorption (5.06?±?0.17?%), water solubility (2.37?±?0.1?%), and lower flexural strength after water immersion (71.4?±?14.6?MPa).     

Biobased isosorbide methacrylate monomer as an alternative to bisphenol A glycerolate dimethacrylate for dental restorative applications

In this study, a new biobased isosorbide urethane methacrylic monomer [isosorbide‐derived urethane dimethacrylate (Is‐UDMA)] was evaluated as a replacement for currently used bisphenol A glycerolate dimethacrylate (Bis‐GMA) based dental restorative materials. Dental composites were prepared at different Is‐UDMA and Bis‐GMA concentrations. For these composites, the photocuring kinetics, volumetric shrinkage, viscoelastic properties, water sorption, and solubility were evaluated. The photocuring kinetics, followed by real‐time IR spectroscopy, showed higher double‐bond conversion (DC) values for the formulations containing the Is‐UDMA monomer; the highest DC (82%) was achieved by the formulation prepared with only the Is‐UDMA monomer. The volumetric shrinkage was reduced to 23.7% as compared with the dental resin formulated with Bis‐GMA. The viscoelastic properties of the formulations containing both Is‐UDMA and Bis‐GMA monomers in a 50:50 composition were superior to the rest of the tested formulations, including those prepared with pure polymers. This behavior was explained in terms of a compromise between crosslinking and rigidity (or flexibility) of the resulting polymer network. A preliminary test on microleakage in a dental enamel demonstrated that the new Is‐UDMA monomer is a potential replacement for the Bis‐GMA monomer in dental restorative materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44591.     

Synthesis and characterization of a dimethacrylates monomer with low shrinkage and water sorption for dental application

In this study, a dimethacrylates monomer 1,3-bis[2-(4-(2′-hydroxy-3′-methacryloyloxy-propoxy)phenyl)-2propyl]benzene (BMPB) was synthesized to replace 2,2-bis[4-(2′-hydroxy-3′-methacryloyloxy-propoxy)phenyl]propane (Bis-GMA) as one component of dental restorative material with the aim of reducing polymerization shrinkage and water sorption. The structure of BMPB was confirmed by FTIR, ¹H-NMR, and elemental analysis. Double bond conversion, polymerization shrinkage, contact angle, water sorption, solubility, flexural strength, and flexural modulus of BMPB/tri(ethylene glycol) dimethacrylate (TEGDMA) based resin were measured. Bis-GMA/TEGDMA based resin was used as reference. The results illustrated that double bond conversion, polymerization shrinkage, water sorption, and solubility of BMPB/TEGDMA were lower than that of Bis-GMA/TEGDMA (P < 0.05). BMPB/TEGDMA had the same flexural strength with Bis-GMA/TEGDMA (P > 0.05), but higher flexural modulus (P < 0.05). Therefore, BMPB could possibly replace Bis-GMA as one component of dental restorative materials with the advantages of similar mechanical properties, being slightly more hydrophobic but presenting less shrinkage. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Benzodioxoles as alternative coinitiators for radical polymerization in a model‐dental adhesive resin

This study evaluated the effectiveness of benzodioxole derivatives as coinitiators of radical polymerization in a model‐dental adhesive resin. To compose the adhesive resin, a monomer mixture based on 50 wt % of Bis‐GMA, 25 wt % of TEGDMA, and 25 wt % of HEMA was used. Camphorquinone (CQ) 1 mol % was used as a photoinitiator to initiate polymerization. 1,3‐Benzodioxole (BDO) and piperonyl alcohol (PA) were used as coinitiators at 0.25, 0.5, 1, 2, 4, 8, and 16 mol % level. In addition, tertiary amine, ethyl 4‐dimethylamino benzoate (EDAB) was used as coinitiator in the control group. Some physical, chemical, and mechanical properties of the polymer formed in the experimental adhesives were evaluated using the kinetics of polymerization, sorption and solubility, flexural strength, and elastic modulus tests. The results indicated that BDO and PA were effective coinitiators in the photoinitiator system based on CQ. Comparisons between the benzodioxoles derivative coinitiators and EDAB showed similar performance in the kinetics of polymerization and flexural strength. For water sorption and solubility evaluation, BDO and PA demonstrated significantly more sorption of water and less solubility than the EDAB control group. The findings suggest that BDO and PA were feasible alternatives to conventional amine as coinitiator. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fabrication and evaluation of light-curing nanocomposite resins filled with surface-modified TiO2 nanoparticles for dental application

A kind of light-curing nanocomposite resin, which consisted of reactive monomers, surface-modified TiO₂ nanoparticles and a photoinitiation system, has been developed for the application of dental restoration. It may be noted that the conjugation of glycidyl methylmethacrylate (GMA) onto the surface of TiO₂ nanoparticles (nano-TiO₂) contributed to improvement in miscibility between nano-filler and matrix, because the reactive C=C group of GMA participated in curing of the matrix, and hence resulted in the enhancement of mechanical properties. When the content of GMA-modified nano-TiO₂ was 2 wt%, the flexural strength and modulus of the nanocomposite resin reached 147.8 and 2918.3 MPa, respectively, which increased by 21.7 and 30.8 % in contrast to the resin without adding nano-filler. Furthermore, the polymerization shrinkage decreased after incorporating the nano-filler while the degree of monomer conversion and the water sorption for the nanocomposite resins was comparable with those of the resin without nano-filler. In conclusion, this study presented a new method, namely introduction of functional groups onto the nano-filler surface to participate in the reaction of resin monomer, to improve the interfacial adhesion and the resultant miscibility between nano-filler and resin matrix in light-curing dental nanocomposites by chemical linkage mediated with surface-modified specie. Moreover, the enhanced mechanical properties and decreased polymerization shrinkage of nanocomposite resins, which are considered the key to the effects of dental restoration, contributed a great potential as a dental material utilized for caries treatment and prevention.     

Effect of cinnamate comonomers on the dental formulation properties

This study reports the synthesis and characterization of two urethane dimethacrylates containing poly(ethylene oxide) or poly(propylene oxide) segment and cinnamate pendant moieties to be formulated in dental resin composites. ¹H NMR, ¹³C NMR, and Fourier transform infrared spectroscopies, gel permeation chromatography, electrospray ionization‐mass spectroscopy, and thermogravimetric measurements confirmed their structure, whereas the photopolymerization evolution of oligodimethacrylates relating to a low–molecular‐weight dicinnamate methacrylate under ultraviolet irradiation was investigated by photo‐differential scanning calorimeter, monitoring the degree of conversion (DC) and polymerization rate. The photopolymerization results reveal that the investigated derivatives display a good photoreactivity (DC: ～ 70%) during the formation of crosslinked polymers, the DC depending especially on the sample viscosity. The polymerization shrinkage for several mixtures including the urethane oligocinnamates (20 wt %) and diglycidyl methacrylate of bisphenol A/triethyleneglycol dimethacrylate system in the absence of filler was determined, the obtained values being in the range of 6.1–8.2 vol %. For few cured specimens incorporating quartz filler (75 wt %), water sorption/solubility, contact angle, and mechanical parameters were measured to establish if such monomers could be of interest in dentistry. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Sorption and permeation properties of water and ethanol vapors in poly[bis(trifluoroethoxy)phosphazene] (PTFEP) membranes

The permeability and solubility for water and ethanol in PTFEP membranes were determined experimentally, and the data were analyzed by the solution-diffusion model. The permeability for water and ethanol ranged from several hundreds to several thousands Barrers, and they increased exponentially with the vapor activity and increased with temperature. At the same temperature and vapor activity, the permeability ratio between water and ethanol ranged from 5.7 to 2.3, and it decreased as the vapor activity increased. The sorption isotherms for water and ethanol were fitted by the Henry’s law relationship. The solubility decreased as the temperature increased so that the heat of sorption for both water and ethanol was negative. The solubility for water was more than twice the solubility for ethanol. The solubility seems to be inversely proportional to the molecular size of the penetrants in such a system. The solubility ratio between water and ethanol is smaller than their molecular volume ratio possibly due to the slightly stronger nonpolar interaction and the higher degree of plasticization in the ethanol-polymer system. The diffusivity for water and ethanol ranged from 10⁻⁸ to 10⁻⁷ cm²/s, and the values for water were larger than those for ethanol at the same temperature and vapor activity. The diffusivity for water and ethanol also increased exponentially with the vapor activity. The diffusivities for water and ethanol increased with temperature and their activation energies of diffusion were very similar possibly due to the same energy characteristic of polymer main chain movement.     

Synthesis and photopolymerization of dicarboxylic acid dimethacrylates and their application as dental monomers

New six dicarboxylic acid dimethacrylates (DMAs) were synthesized and studied as photocurable dental monomers. The photopolymerization behavior of the monomers was investigated by FTIR spectroscopy using camphorquinone (CQ) and 2‐(dimethylamino)ethyl MA (DMAEMA) as a photoinitiating system. Relatively high conversions (>55%) resulted from photopolymerization of the monomers by visible light. The volume shrinkage of the monomers during photopolymerization was significantly influenced by their molecular weight and degree of conversion. Preliminary tests of the composites formulated with a dicarboxylic acid DMA, a diluent, CQ, DMAEMA, and a glass filler were carried out including a three‐point bending test and fluoride release. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1802–1808, 2000     

Effect of disinfection by microwave irradiation on the strength of intact and relined denture bases and the water sorption and solubility of denture base and reline materials

This study evaluated the influence of microwave disinfection on the strength of intact and relined denture bases. Water sorption and solubility were also evaluated. A heat‐polymerized acrylic resin (Lucitone 550) was used to construct 4‐mm‐thick (n = 40) and 2‐mm‐thick (n = 160) denture bases. Denture bases (2‐mm) were relined with an autopolymerizing resin (Tokuso Rebase Fast, Ufi Gel Hard, Kooliner, or New Truliner). Specimens were divided into four groups (n = 10): without treatment, one or seven cycles of microwave disinfection (650 W for 6 min), and water storage at 37°C for 7 days. Specimens were vertically loaded (5 mm/min) until failure. Disc‐shaped specimens (50 mm × 0.5 mm) were fabricated (n = 10) to evaluate water sorption and solubility. Data on maximum fracture load (N), deflection at fracture (mm), fracture energy (N mm), water sorption (%), and solubility (%) were analyzed by two‐way analysis of variance and Student–Newman–Keuls tests (α = 0.05). One cycle of microwave disinfection decreased the deflection at fracture and fracture energy of Tokuso Rebase Fast and New Truliner specimens. The strength of denture bases microwaved daily for 7 days was similar to the strength of those immersed in water for 7 days. Microwave disinfection increased the water sorption of all materials and affected the solubility of the reline materials. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of a monofunctional analog to BIS-GMA: A dental monomer

A new monofunctional BIS-GMA monomer, 4-(2-phenyl isopropyl)-3-phenoxy-2-hydroxy propyl methacrylate (monofunctional-BIS-GMA, hereafter abbreviated as MF-BIS-GMA) was synthesized as an adduct of 4-cumylphenol and glycidyl methacrylate for use as a dental monomer. The new monomer was characterized by FTIR, ¹H, ¹³C (attached proton test, APT), UV, HPLC, and GPC. The viscosity and solubility of the new resin are also presented. The results were compared with the difunctional analog, BIS-GMA (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)]phenyl propane), which is commercially available and currently used in dental restorative materials. Both monomers were light-cured using 0.3% camphorquinone and 0.75% 2-(dimethylamino)ethyl methacrylate as photoinitiators. The extent of monomer conversion and the potential for residual monomer leachability were compared between the two cured resins. The monofunctional resin was found to yield higher monomer conversion values (74 vs. 39%) and lower leachable components (0.03 vs. 30.6 mol %) than those of the difunctional analog. © 1995 John Wiley & Sons, Inc.     

Sorption,diffusion and pervaporation of water/ethanol mixtures in polyetherimide membranes

Homogeneous and composite aromatic polyetherimide membranes were prepared by casting from N-methylpyrrolidinone (NMP) solutions and by electrodeposition of polymer at the cathode, respectively. The membranes were evaluated for their sorption, diffusion and pervaporation separation of water from ethanol with emphasis on the breaking of azeotropic composition. The membrane performance was shown to be dependent on the feed concentration, but still selective towards water over the whole composition range of the feed mixture. By looking at the surface energy parameters, the determination of degree of swelling and the calculation of deviation coefficients (ε), an interesting insight was gained into the coupling effect in this solvent/membrane system. From the sorption, diffusion and temperature-dependent permeation behaviour, it could be concluded that in this system the diffusivity of permeant plays a major role in determining the pervaporation performance, rather than the solubility. © 1999 Society of Chemical Industry     

Composite resins based on novel and highly reactive bisglycidyl methacrylate monomers

Three new bisglycidyl monomers; 1,4‐bis((2‐hydroxy‐3‐methacryloxypropoxy) methyl)benzene (MB‐Phe‐OH), 1,4‐bis(2‐hydroxy‐3‐methacryloxypropoxy)2‐cis‐butene (MB‐Cis‐OH), and 1,7‐bis(2‐hydroxy‐3‐methacryloxypropoxy)heptane (MB‐1,7‐OH); were synthesized and used as Bis‐GMA/TEGDMA (bisphenolglycidyl methacrylate/triethylene glycol dimethacrylate) composite resin additives. Flexural properties and double bond conversion of the dental resins composed of silanizated inorganic filler and organic matrices containing new monomers were evaluated. The composite resins formulated, using the monomers MB‐Cis‐OH and MB‐1,7‐OH, have mechanical properties and double bond conversion comparable with those of Bis‐GMA/TEGDMA composite resin used as control. The composite containing the new monomer MB‐Phe‐OH has better flexural properties (flexural strength 65.01 MPa and flexural modulus 5675.91 MPa) than the control composite resin (flexural strength 52.85 MPa and flexural modulus 4879.72 MPa); this could be attributed to the molecular structure of the monomer and its high double bond conversion level of 74.19%. The new bisglycidyl methacrylate monomer MB‐Phe‐OH could be potentially useful in the development of new organic matrices for dental composite resins with high double bond conversion and enhanced mechanical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40971.