Thermochemical Response of Vinyl-Ester Resin

Fink, Bruce K.; Bogetti, Travis A.; Stone, Molly A.; Gillespie, John W.; ., Jr.

doi:10.21236/ada399117

Cited by 5 publications

(2 citation statements)

References 2 publications

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“…42 In the case of the BisGMA-rich phases, further propagation of the polymerization reaction is limited by the diffusion rate of the reactive species from the monomer-water mixture into the microgel, which depends on the viscosity of the resin. 43 A similar phenomenon has been observed for vinyl-ester microgels 51 and also as the cage effect for free radical polymerization. 52 B. Cross-link density Figure 4 shows both the effective cross-link density ν e , calculated using Eq.…”

Section: A Degree Of Conversionsupporting

confidence: 70%

Structure–property relationships for wet dentin adhesive polymers

et al. 2018

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Dentin adhesive systems for composite tooth restorations are composed of hydrophilic/hydrophobic monomers, solvents, and photoinitiators. The adhesives undergo phase separation and concomitant compositional change during their application in the wet oral environment; phase separation compromises the quality of the hybrid layer in the adhesive/dentin interface. In this work, the adhesive composition in the hybrid layer can be represented using the phase boundaries of a ternary phase diagram for the hydrophobic monomer/hydrophilic monomer/water system. The polymer phases, previously unaccounted for, play an important role in determining the mechanical behavior of the bulk adhesive, and the chemomechanical properties of the phases are intimately related to the effects produced by differences in the hydrophobic-hydrophilic composition. As the composition of the polymer phases varies from hydrophobic-rich to hydrophilic-rich, the amount of the adsorbed water and the nature of polymer-water interaction vary nonlinearly and strongly correlate with the change in elastic moduli under wet conditions. The failure strain, loss modulus, and glass transition temperature vary nonmonotonically with composition and are explained based upon primary and secondary transitions observed in dynamic mechanical testing. Due to the variability in composition, the assignment of mechanical properties and the choice of suitable constitutive models for polymer phases in the hybrid layer are not straightforward. This work investigates the relationship between composition and chemomechanical properties of the polymer phases formed on the wateradhesive phase boundary using quasistatic and dynamic mechanical testing, mass transfer experiments, and vibrational spectroscopy.

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Section: A Degree Of Conversionsupporting

confidence: 70%

Structure–property relationships for wet dentin adhesive polymers

et al. 2018

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“…It can be seen that the hardness of neat VE increases from 10.6 Hv to 12.8 Hv when it is filled with 5 wt% CSP. This may be attributed to degree of cure of the VE resin , uniform dispersion and better interfacial bonding between the silane treated CSP particles in the VE resin. Similarly, the hardness increased for composites containing coir/aramid and their hybrid VE composites.…”

Section: Resultsmentioning

confidence: 99%

Effect of treated coir fiber/coconut shell powder and aramid fiber on mechanical properties of vinyl ester

Kumar¹,

Ramalingaiah²,

Rajini

et al. 2017

Polymer Composites

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The surfaces of coir fiber (CF) and coconut shell powder (CSP) were modified by alkali and silane treatment respectively to investigate the consequent effects on reinforcement of vinyl ester (VE) composites. Mono‐composites of VE with surface treated CFs and CSP as well as their hybrid composites with as‐received aramid fibers (AFs) have been prepared by hand layup followed by compression molding methods. The effectiveness of surface treated reinforcements in improving the mechanical properties of the composites was demonstrated. Significant differences between VE mono‐composites and their hybrid reinforcements on hardness and tensile properties of VE were observed, while no improvement in the above‐mentioned properties except for Young's modulus was observed for hybrid composite with AFs. It was also observed that surface treated CFs and CSP reinforced VE composites exhibited better hardness and tensile properties. SEM imaging confirmed decreased fiber pull‐out for VE reinforced with alkali treated CFs because of the enhanced adhesion between the CFs and the VE matrix. Flexural properties of all the composites decreased. This study has proved that the mechanical properties of hybrid VE composites can be enhanced by modifying the reinforcements by alkali and silane into their formulations. These results have been explained on the basis of structure and morphology in terms of fractography of VE composites. Furthermore, this study demonstrates that alkali treatment is a promising technique for improving the mechanical properties such as hardness and tensile properties of CF reinforced hybrid polymer matrix composites. POLYM. COMPOS., 39:4542–4550, 2018. © 2017 Society of Plastics Engineers

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