Bond Conversion Research Articles

Light-Induced Effects in Amorphous Chalcogenide Glasses: Femtoseconds to Seconds

Amorphous chalcogenide glasses are intrinsically metastable, highly photosensitive, and therefore exhibit numerous light-induced effects upon bandgap and sub-bandgap illumination. Depending on the pulse duration of the excitation laser, ChGs exhibit a series of light-induced effects spanning over femtosecond to seconds time domain. For continuous wave (CW) illumination, the effects are dominantly metastable in terms of photodarkening (PD) and photobleaching (PB) that take place via homopolar to heteropolar bond conversion. On the other hand, under nanosecond and ultrafast pulsed illumination, ChGs exhibit transient absorption (TA) that is instigated from the transient bonding rearrangements through self-trapped exciton recombination. In the first part of the review, we pay special attention to continuous wave light-induced PD and PB, while in the second part we will focus on the TA and controlling such effects via internal and external parameters, e.g., chemical composition, temperature, sample history, etc.

Renewable UV-curable polyester methacrylate/cellulose nanocrystals composite resin for wood waterproof coating

Low-viscosity UV-curable resins are widely used in industry as they allow for UV curing materials with reduced amounts of reactive diluents to adjust the viscosity. But their mechanical properties and waterproof performance after curing as UV coatings still need to be improved. Here, a series of low-viscosity bio-based UV-curable polyester methacrylates were synthesized through L-lactide (LA) and ε-caprolactone (CL) monomers. The results show that the introduction of star-shaped structure and random copolymerization of LA and CL can effectively reduce the viscosity of the resin to 313 mPa · s and at the same time increase the double bond conversion rate and maintain good mechanical properties. The composite resin was prepared by blending the star-shaped low-viscosity polyester methacrylate resin with cellulose nanocrystals (CNCs), and the microstructure was characterized by XRD and TEM. The curing kinetics, mechanical properties, thermal properties and waterproof properties of the composite resin were further tested. When the mass fraction of CNCs is 2.5 wt%, the water absorption rate of the pine samples coated with UV-cured composite resin is reduced to 17%, which is 65% lower than that of the uncoated samples and 20% lower than that of the samples coated with resin without CNC. This article provides a feasible and effective method for improving the mechanical properties and waterproof performance of low-viscosity UV-curing resins.

UV-Light Curing of 3D Printing Inks from Vegetable Oils for Stereolithography.

Typical resins for UV-assisted additive manufacturing (AM) are prepared from petroleum-based materials and therefore do not contribute to the growing AM industry trend of converting to sustainable bio-based materials. To satisfy society and industry’s demand for sustainability, renewable feedstocks must be explored; unfortunately, there are not many options that are applicable to photopolymerization. Nevertheless, some vegetable oils can be modified to be suitable for UV-assisted AM technologies. In this work, extended study, through FTIR and photorheology measurements, of the UV-curing of epoxidized acrylate from soybean oil (AESO)-based formulations has been performed to better understand the photopolymerization process. The study demonstrates that the addition of appropriate functional comonomers like trimethylolpropane triacrylate (TMPTA) and the adjusting of the concentration of photoinitiator from 1% to 7% decrease the needed UV-irradiation time by up to 25%. Under optimized conditions, the optimal curing time was about 4 s, leading to a double bond conversion rate (DBC%) up to 80% and higher crosslinking density determined by the Flory–Rehner empirical approach. Thermal and mechanical properties were also investigated via TGA and DMA measurements that showed significant improvements of mechanical performances for all formulations. The properties were improved further upon the addition of the reactive diluents. After the thorough investigations, the prepared vegetable oil-based resin ink formulations containing reactive diluents were deemed suitable inks for UV-assisted AM, giving their appropriate viscosity. The validation was done by printing different objects with complex structures using a laser based stereolithography apparatus (SLA) printer.

Curing and properties of urethane acrylates with different functionalities under electron-beam and ultraviolet irradiation

In this study, four model urethane acrylates with different functionalities were synthesized and their structures were characterized using infrared spectroscopy, nuclear magnetic resonance spectroscopy, and gel permeation chromatography. Pure urethane acrylates were then irradiated with energy-equivalent electron-beam (EB) and ultraviolet (UV), and the acrylate structure and curing degree after irradiation were studied. The results of double bond conversion and gel content revealed that the curing degree of EB-cured samples was higher than that of UV-cured samples under equivalent energy. Furthermore, the energy supply mode was changed from one-time to multiple superimposition, which clarified that the in situ polymerization effect of EB irradiation could produce a high curing degree. Finally, pure urethane acrylates were mixed with commercial oligomer, and the glass transition temperature and pendulum hardness of the cured products were investigated. Moreover, the performance of cured films and coatings was affected by multiple factors, such as functionality, irradiation type and energy supply mode.

Roll-to-roll micromolding of UV curable coatings

In this study, fast and continuous fabrication of microscale structures by roll-to-roll UV imprinting or micromolding is demonstrated on a 121 mm wide web. This process is enabled by a UV curable thiol-ene-acrylate resin system, following the work of Stadlober and coworkers. A series of formulations were prepared with fast curing speeds at ambient conditions, low viscosities, and tunable mechanical properties. The rate and extent of curing as a function of the formulation composition were investigated with Fourier transform infrared spectroscopy. Consistent with the past work, we show that the thiol-ene-acrylate formulations reached high double bond conversions (> 80%) with the maximum conversion increasing with the relative thiol content and decreasing with the viscous urethane acrylate oligomer content. The double bond conversion of the patterned coatings (in contact with the mold) is shown to be ~ 80% for a range of UV lamp powers and web speeds up to 2.7 cm/s. Areas of the coating not covered by the mold required higher UV lamp power and/or lower web speeds to cure to a tack-free state. Microscale channels and arrays of recessed wells with various dimensions and pattern densities were continuously fabricated. Our findings show the successful use of a tetrafunctional thiol in the thiol-ene-acrylate resin system. We also discuss guidelines for the selection of processing conditions for the manufacturing of structured plastic substrates using roll-to-roll imprinting processes, opening up potential new applications.

A comprehensive investigation of acrylates photopolymerization shrinkage stress from micro and macro perspectives by real time MIR-photo-rheology

The acrylate photocuring system with the high curing rate are widely used in various industries. However, the rapid polymerization kinetics can cause the surge of resin viscosity and the gel point can be reached in advance. This can results in the restriction of molecular chain movement and internal stress release is thus hindered during the photopolymerization. Finally, it usually leads to the poor performance of UV-cured materials with lower double bond conversion and large volume shrinkage and shrinkage stress. In order to understand the relationship between properties and polymerization process, this paper employed the combined technique of the mid-infrared spectrometer and photo-rheometer to monitor the acrylate free radical photopolymerization process. The effects of curing conditions (curing temperature, radiant intensity and sample thickness) and system compositions (diluent functionality, diluent segment length) on the rheological properties and chemical conversion of materials were fully investigated. Finally, a standard protocol is established to evaluate the reactivity, mechanical properties and volume shrinkage of the photocuring system. Simultaneously, the double bond conversion of the reaction system can be achieved through calculation of peak area of IR absorption. A complex nonlinear relationship between the storage modulus, shrinkage stress and double bond conversion is established.

Optimization of linear and nonlinear optical parameters of As40Se50Te10 thin films by thermal annealing

The present study reports the linear and nonlinear optical properties of as-prepared and annealed As40Se50Te10 thin films prepared on glass substrate by thermal evaporation method. The modifications in different properties after annealing were studied by XRD, EDAX, Raman spectroscopy, FESEM and UV–Vis-NIR and XPS spectroscopy. The study reports the decrease in optical band gap due to increase in disorder while the width of the tail in the gap increased with annealing temperature. The linear refractive index, optical as well as electrical conductivity and extinction coefficient increased with annealing. The dispersion energy, oscillator energy, dielectric constant and oscillator strength increased with annealing temperature while the electrical susceptibility decreased upon annealing. The 3rd order optical susceptibility and nonlinear refractive index were found to be increased with annealing temperature. The influence of different annealing temperatures on the variation of different parameters were elaborately explained on the basis of defect states in localized region. The structure remained unchanged while the heteropolar to homopolar bond conversion was noticed from the XPS and Raman spectroscopy. The changes in both nonlinear and linear optical properties by annealing shows that annealing temperature can be used as an important tool for controlling the optical constants of As40Se50Te10 chalcogenide film which could be a suitable candidate for numerous photonic applications.

Impact of Fast High-Intensity versus Conventional Light-Curing Protocol on Selected Properties of Dental Composites.

To study the influence of fast high-intensity (3-s) and conventional (20-s) light curing protocols on certain physical properties including light-transmission and surface wear of two nano-hybrid composite resins (Tetric PowerFill and Essentia U) specifically designed for both curing protocols. According to ISO standards, the following properties were investigated: flexural properties, fracture toughness and water sorption/solubility. FTIR-spectrometry was used to calculate the double bond conversion (DC%). A wear test using a chewing simulator was performed with 15,000 chewing cycles. A tensilometer was used to measure the shrinkage stress. Light transmission through various thicknesses (1, 2, 3 and 4 mm) of composite resins was quantified. The Vickers indenter was utilized for evaluating surface microhardness (VH) at the top and the bottom sides. Scanning electron microscopy was utilized to investigate the microstructure of each composite resin. The light curing protocol did not show a significant (p > 0.05) effect on the mechanical properties of tested composite resins and differences were material-dependent. Shrinkage stress, DC% and VH of both composite resins significantly increased with the conventional 20 s light curing protocol (p < 0.05). Light curing conventional composite resin with the fast high-intensity (3-s) curing protocol resulted in inferior results for some important material properties.

Prilezhaev epoxidation of oleic acid in the presence and absence of ultrasound irradiation

AbstractBACKGROUNDEpoxidation of double bonds in vegetable oils provide valuable green intermediates for the chemical industry. The epoxidation of oleic acid with hydrogen peroxide according to the Prilezhaev principle was studied experimentally in a multiphase laboratory‐scale batch reactor operated isothermally at 50 °C and atmospheric pressure. A solid cation exchanger (Amberlite IR‐120) was used as the solid catalyst to enhance the slow step in the Prilezhaev process: the in situ formation of the epoxidation agent, peracetic acid, from hydrogen peroxide and acetic acid. A rotating basket stirrer was used to suppress the external mass transfer limitations and to guarantee a turbulent random flow in the vicinity of the catalyst particles. Kinetic experiments demonstrated the catalytic effect of the cation exchanger. Several experiments were performed in the presence and absence of ultrasound irradiation at different amplitudes.RESULTSThe exposure of ultrasound irradiation on the multiphase reaction mixture impaired the conversion of the double bonds and the yield of the epoxide, compared to a reference experiment conducted under silent conditions. Catalyst characterization by scanning electron microscopy and the determination of the acid sites in recycled catalyst samples confirmed that the main reason for deactivation was leaching and/or neutralization of the sulfonic acid groups from the solid catalyst matrix.CONCLUSIONSThe application of ultrasound at different input powers resulted in lower reaction yields compared to the silent reference experiment. This observation was attributed to deactivation of the catalyst caused by leaching and/or neutralization of the sulfonic groups promoted by ultrasound exposure. © 2021 Society of Chemical Industry (SCI).

Reassessing Alkyne Coupling Reactions While Studying the Electronic Properties of Diverse Pyrene Linkages at Surfaces.

The combination of alkyne and halogen functional groups in the same molecule allows for the possibility of many different reactions when utilized in on-surface synthesis. Here, we use a pyrene-based precursor with both functionalities to examine the preferential reaction pathway when it is heated on an Au(111) surface. Using high-resolution bond-resolving scanning tunneling microscopy, we identify multiple stable intermediates along the prevailing reaction pathway that initiate with a clearly dominant Glaser coupling, together with a multitude of other side products. Importantly, control experiments with reactants lacking the halogen functionalization reveal the Glaser coupling to be absent and instead show the prevalence of non-dehydrogenative head-to-head alkyne coupling. We perform scanning tunneling spectroscopy on a rich variety of the product structures obtained in these experiments, providing key insights into the strong dependence of their HOMO–LUMO gaps on the nature of the intramolecular coupling. A clear trend is found of a decreasing gap that is correlated with the conversion of triple bonds to double bonds via hydrogenation and to higher levels of cyclization, particularly with nonbenzenoid product structures. We rationalize each of the studied cases.

Probing Structural Information of Gas-Phase Peptides by Near-Edge X-ray Absorption Mass Spectrometry.

Near-edge X-ray absorption mass spectrometry (NEXAMS) is an action-spectroscopy technique of growing interest for investigations into the spatial and electronic structure of biomolecules. It has been used successfully to give insights into different aspects of the photodissociation of peptides and to probe the conformation of proteins. It is a current question whether the fragmentation pathways are sensitive toward effects of conformational isomerism, tautomerism, and intramolecular interactions in gas-phase peptides. To address this issue, we studied the cationic fragments of cryogenically cooled gas-phase leucine enkephalin ([LeuEnk+H]+) and methionine enkephalin ([MetEnk+H]+) produced upon soft X-ray photon absorption at the carbon, nitrogen, and oxygen K-edges. The interpretation of the experimental ion yield spectra was supported by density-functional theory and restricted-open-shell configuration interaction with singles (DFT/ROCIS) calculations. The analysis revealed several effects that could not be rationalized based on the peptide's amino acid sequences alone. Clear differences between the partial ion yields measured for both peptides upon C 1s → π*(C═C) excitations in the aromatic amino acid side chains give evidence for a sulfur-aromatic interaction between the methionine and phenylalanine side chain of [MetEnk+H]+. Furthermore, a peak associated with N 1s → π*(C═N) transitions, linked to a tautomeric keto-to-enol conversion of peptide bonds, was only present in the photon energy resolved ion yield spectra of [MetEnk+H]+.

Novel core–shell CHX/ACP nanoparticles effectively improve the mechanical, antibacterial and remineralized properties of the dental resin composite

ObjectiveThe core–shell chlorhexidine/amorphous calcium phosphate (CHX/ACP) nanoparticles were synthesized and used to modify the dental resin composite, aiming to improve its remineralized and antibacterial properties. MethodsThe core–shell CHX/ACP nanoparticles were synthesized by vesicle-templating technology and characterized, and their sustained release and antibacterial properties were also evaluated. Subsequently, the synthesized nanoparticles were incorporated into the dental resin composite at 1 wt.%, 5 wt.% or 10 wt.% to obtain different experimental groups. The physical properties, including curing depth, double bond conversion rate, water absorption and solubility, the sustained-release effects, and mechanical properties of the modified resin composite were evaluated. The remineralization ability was also measured by SEM. The antibacterial experiment of the modified resin composite with fresh preparation or aging in water for 28 days was carried out by a plate count method. ResultsThe physical and chemical characterizations showed that the synthesized nanoparticles presented a core–shell structure, and their diameter was about 98.5 nm. The shell was composed of ACP with the core full of CHX. These nanoparticles had a release effect on calcium, phosphate ions, and CHX. The nanoparticles could effectively inhibit the growth of S. mutan at a lower concentration (≥50 μg/mL). The curing depth, the double bond conversion, the water absorption, the solubility, the flexural strength, the flexural modulus, and the compressive strength of the modified resin composite were 3.86–4.88 mm, 62.32–73.61%, 1.47–2.84%, 0.21−0.48%, 45.83–109.46 MPa, 2.57–4.91 GPa, and 66.43–160.38 MPa, respectively. The modified resin composite containing 5 wt.% and above CHX/ACP nanoparticles could effectively inhibit the growth of S. mutans regardless of aging in water, with immediate and aging antibacterial rate of more than 92%. In addition, the modified resin composite had a certain remineralization property in the SBF solution verified by SEM. SignificanceThe core–shell CHX/ACP nanoparticles were successfully prepared and used to modify the resin composite. The modified dental resin composite with 5 wt.% CHX/ACP nanoparticles had excellent mechanical, antibacterial, and remineralization properties. It is expected to be an ideal restorative filling material for clinical application.

Differentiation of physical and chemical cross-linking in gelatin methacryloyl hydrogels

Gelatin methacryloyl (GM) hydrogels have been investigated for almost 20 years, especially for biomedical applications. Recently, strengthening effects of a sequential cross-linking procedure, whereby GM hydrogel precursor solutions are cooled before chemical cross-linking, were reported. It was hypothesized that physical and enhanced chemical cross-linking of the GM hydrogels contribute to the observed strengthening effects. However, a detailed investigation is missing so far. In this contribution, we aimed to reveal the impact of physical and chemical cross-linking on strengthening of sequentially cross-linked GM and gelatin methacryloyl acetyl (GMA) hydrogels. We investigated physical and chemical cross-linking of three different GM(A) derivatives (GM10, GM2A8 and GM2), which provided systematically varied ratios of side-group modifications. GM10 contained the highest methacryloylation degree (DM), reducing its ability to cross-link physically. GM2 had the lowest DM and showed physical cross-linking. The total modification degree, determining the physical cross-linking ability, of GM2A8 was comparable to that of GM10, but the chemical cross-linking ability was comparable to GM2. At first, we measured the double bond conversion (DBC) kinetics during chemical GM(A) cross-linking quantitatively in real-time via near infrared spectroscopy-photorheology and showed that the DBC decreased due to sequential cross-linking. Furthermore, results of circular dichroism spectroscopy and differential scanning calorimetry indicated gelation and conformation changes, which increased storage moduli of all GM(A) hydrogels due to sequential cross-linking. The data suggested that the total cross-link density determines hydrogel stiffness, regardless of the physical or chemical nature of the cross-links.

The conversion of ether bonds to hydroxyl via a base-promoted rearrangement of cyclic phosphine oxides

Biphenyl derived secondary phosphine oxides having 2′-hydroxyl were prepared.

Radical-induced cationic frontal polymerisation for prepreg technology

In this study, a new type of prepreg technology has been established using a dual curing system consisting of 1,6-hexanediol diacrylate (HDDA) and frontally polymerisable components based on the epoxide resin. The study of the polymerisation of HDDA revealed (tert-butylcyclohexyl)peroxydicarbonate (BCPC) as the most suitable radical thermal initiator. The presence of BCPC resulted in a fast radical polymerisation of HDDA and no cationic ring-opening reaction of the epoxy, which was observed by monitoring the double bond and epoxy group conversion in real time-NIR rheology measurement. The formed prepreg can subsequently be cured by radical-induced cationic frontal polymerisation of the epoxy resin. Effects of HDDA amount on the radical polymerisation, stiffness of the gel, frontal parameters and thermal mechanical properties of final polymers were investigated. With 10 wt% HDDA, the formed prepreg has very good storage stability, which was proved by monitoring the epoxy group conversion during 4 months of storage at 50 °C while still a stable front can be obtained. Furthermore, the RICFP-prepregs with different fibre contents were prepared and polymerised by RICFP. Then, a snowflake composite was successfully produced using RICFP-prepreg.Graphic abstract

Bio-based polyfunctional reactive diluent derived from tung oil by thiol-ene click reaction for high bio-content UV-LED curable coatings

Materials with high bio-content have gradually replaced petroleum-based materials due to their sustainability, low cost, low toxicity and excellent performance in the field of UV-LED curable coatings. A novel tung oil-based methacrylate (TDMM) with low viscosity and multiple photopolymerizable methacrylates was designed and synthesized through three steps containing amidation, thiol-ene click reaction and esterification. The reaction conditions for thiol-ene click reaction were optimized by calculating double bond conversion and degree of functionalization of polyols. The chemical structures of the as-prepared TDMM were characterized by 1H NMR and FTIR. The rheological behavior analysis indicated that TDMM exhibited lower viscosity than petrochemical-based reactive diluent pentaerythritol triacrylate (PETA). Subsequently, TDMM showed good copolymerization ability with soybean oil-based reactive monomer (AESO) under the “green + green” UV-LED curable systems with high bio-content (61–81% in theory). The TDMM/AESO systems showed higher Tg but lower thermal stability, better modulus and tensile strength than the neat AESO. Besides, the UV-LED cured coatings exhibited excellent physical and chemical properties. This bio-renewable tung oil-based monomer is shown to be an effective reactive diluent and considered to have good potential in the development of the UV-LED curable coatings.

Effect of Curing Protocol on Mechanical Behavior of Green Ceramic Bodies Fabricated in Ceramic Microstereolithography

The present work is based on investigation of mechanical behavior of green ceramic parts fabricated in scanning based ceramic microstereolithography (CM SL). This study is essential as many times green ceramic bodies fabricated by microstereolithography (MSL) can be directly incorporated in microelectromechanical systems (MEMS). These green parts are fabricated from ceramic suspensions obtained by dispersing ceramic particles in photocurable (meth)acrylate resins separately. As fabricated parts in CMSL are essentially polymer-ceramic composites whose strength mainly depends on cross link density. Nanoindentation and glass transition temperature derived from DSC were used to compare cross link density of green ceramic bodies fabricated from (meth)acrylate suspensions. Further, double bond conversion, which is indicative of cross link density, was verified by FTIR. These results suggested that there is significant influence of curing protocol on mechanical behavior of green ceramic parts

Commercially available granulates PMMA and PS - potential problems with the production of polymer optical fibers

The aim of the study was to verify the usefulness of commercially available granulates of PMMA (poly (methyl methacrylate) and PS (polystyrene) for the production of polymer optical fibers by extrusion method. Samples were subjected to thermal processing in various conditions (different temperatures and exposure time). Thermal (TG/DTG) and spectroscopic (ATR/FT-IR) analyses were carried out to analyze changes in the samples. Based on FT-IR analysis of liquid monomers and granulates the conversion of double bonds was calculated, which gave us a picture of the degree of monomers conversion, crucial information from the technological point of view. Full Text: PDF ReferencesO. Ziemann, J. Krauser, P.E. Zamzow, W. Daum, POF Polymer Optical Fibersfor Data Communication (Berlin: Springer 2008). DirectLink P. Stajanca et al. "Solution-mediated cladding doping of commercial polymer optical fibers", Opt. Fiber Technol. 41, 227-234, (2018). CrossRef K. Peters, "Polymer optical fiber sensors—a review", Smart Mater. Struct., 20 013002 (2011) CrossRef J. Zubia and J. Arrue, "Plastic Optical Fibers: An Introduction to Their Technological Processes and Applications", Opt. Fiber Technol. 7 ,101-40 (2001) CrossRef M. Beckers, T. Schlüter, T. Gries, G. Seide, C.-A. Bunge, "6 - Fabrication techniques for polymer optical fibres", Polymer Optical Fibres, 187-199 (2017) CrossRef M. Niedźwiedź , M. Gil, M. Gargol , W. Podkościelny, P. Mergo, "Determination of the optimal extrusion temperature of the PMMA optical fibers", Phot. Lett. Poland 11, 7-9 (2019) CrossRef

Facile synthesis of poly(isobutylene-co-isoprene) (IIR) carboxylated derivatives by thiol–ene click chemistry

The thiol–ene click reaction was applied to modify poly(isobutylene-co-isoprene) (IIR) by two different strategies using carboxylated thiols (mercaptanoic acids) with different alkyl spacer chain lengths. In the first approach, the direct radical-promoted addition of thiols across the 1,4-isoprene units proceeded with 80–90% conversion of the internal double bonds. An alternate method involving the conversion of sterically hindered 1,4-isoprene units to pendant double bonds through epoxidation and hydrolysis prior to the click reaction proceeded with 90–98% conversion of the alkene moieties. The carboxylated IIR derivatives were characterized by 1H NMR, FT-IR spectroscopy, and gel permeation chromatography analysis. Irrespective of the synthetic strategy used, the yields of the reactions decreased as the length of the alkyl spacer in the mercaptanoic acid increased. The outcomes of the reactions also depended on the amounts of solvent and free radical initiator used. Carboxylated butyl rubber derivatives were obtained by reacting the isoprene units in the isobutylene copolymer with alkylmercaptanoic acids comprising alkyl spacers of different lengths. The yield of the reactions varied from 80 to 90% for direct reaction of the copolymer containing 1,4-isoprene units, but increased to 90–98% if the 1,4-units were isomerized to terminal alkenes prior to the reactions.

Compositional effects on mechanical properties and viscosity in UDMA-MMA blends

Photo-cured adhesives based on methyl methacrylate (MMA) are common, but MMA has a low molecular weight and low viscosity which is not ideal in some situations. The addition of high molecular weight of diurethane dimethacrylate (UDMA) is an attractive proposition as it increases viscosity and reduces photo-cure times. Photo-cured blends with 30, 40, 50, 60, and 70 wt.% UDMA in MMA plus camphorquinone (CQ) and ethanol were tested by nanoindentation, tensile testing, viscosity measurements, and vibrational spectroscopy. Changes in mechanical properties with composition ranged from hardness which showed a small increase with UDMA wt.%, to indentation modulus which was largely unchanged, to tensile modulus which showed a small decrease. The hardness increase is counter to the other mechanical changes and may be due to increased hydrogen bonding as seen in the vibrational spectra. Higher UDMA percentages gave a noticeable decrease in tensile strength, but an increase in the viscosity of the uncured liquid. The blends were all superior mechanically to UDMA on its own. Spectroscopy indicated a decreasing degree of conversion of double bonds as UDMA increases, which explains many of the property changes. The results show MMA-UDMA composition can be tuned for specific applications where viscosity and photo-curing time is important while still maintaining good mechanical properties. Compositions in the range 30–50 wt. % UDMA offer a balance of good mechanical properties, relatively short photo-cure times, and low viscosity which are needed to penetrate deep, narrow gaps.