Optimum pressure for the high-pressure polymerization of urethane dimethacrylate

Bonding between CAD/CAM resin and resin composite cements dependent on bonding agents: three different in vitro test methods

“…Further developments led to new and improved classes of resin materials, which can be optimized by variation in view of the matrix and/or the fillers [12]. The standardized industrial polymerization of CAD/CAM resins under high pressure [14,15] or heat treatment [16] results in a higher degree of conversion with fewer residual monomer -containing free double bounds -in the material. Due to the low number of reaction units, the bonding to the resin composite cement seems to be difficult [17].…”

Water ageing of urethane dimethacrylate networks

“…According to DVS results, it seems that the polymer-water interaction parameter is almost constant, irrespectively of the polymerization pressure. This result is worth to be discussed since polymerization pressure was shown to influence the conversion degree of samples [25], and their subsequent structure at "molecular" and macromolecular level.…”

“…Samples were obtained by bulk radical polymerization of UDMA (CAS 72869-86-4 supplied by Esstech, Germany) initiated by 0.5% Benzoyl Peroxide (ref 00213 -Sigma Aldrich) at 90 C under atmospheric air (0.1 MPa) or under various pressures (100, 200 and 300 MPa) in custom built autoclave as described in Ref. [25]. The UDMA structure and the expected network structure are given in Scheme 1.…”

“…-conversion degree (DC) was measured from Near InfraRed spectroscopy as described in Ref. [25]. Experiments were repeated 10 times.…”

“…In conclusion, our results mean that the polymerization pressure does not significantly change the cohesive energy, polymer polarity and later affinity with water which is expressed by the maximal water uptake. It remains possible however that some difference in water uptake exists in the case of samples displaying a wider range of conversion degree [13] but this is not the case for pure UDMA samples [25] where conversion degree always are higher than 90%.…”