The purpose of this study was to analyze the curing behavior of a nanocomposite by assessing in real time the degree of cure at depths of 2 mm and 6 mm. The variation of hardness with depth, shrinkage stress, and curing time until gelation with 16 curing regimes was further investigated using one halogen and three LED curing units. In the present study, it was shown that the soft-start polymeri...

A method was developed for the fractionation of grape and wine proanthocyanidins according to their degree of polymerization. The grape and wine proanthocyanidins were fractionated on C18 Sep-Pak cartridges into three fractions by different organic solvents. The combination of TLC, analytic HPLC, and degradation with toluene-R-thiol confirmed that these three fractions contained, respectively, ...

Carothers and Flory established the fundamental principles of homogeneous two-component polycondensation reactions by which a variety of commonly used polymers such as polyesters and polyamides (nylons) are synthesized even now. One of the most critical factors to achieve a high degree of polymerization is a strict adherence of stoichiometric balance of the two components. An imbalanced ratio o...

The recent development of algebraic explicit stress models (AESM) for viscoelastic fluids rests upon a general equilibrium assumption, by invoking a slow variation condition on the evolution of the viscoelastic anisotropy tensor (the normalized de-viatoric part of the extra-stress tensor [G. Mompean, R.L. Thompson, P.R. Souza Mendes, A general transformation procedure for differential viscoelas...

Background and Aim: Minimizing the polymerization shrinkage of composite resins is a critical goals in composite restorations. Many factors affect polymerization shrinkage. This study aimed to evaluate the effect of composite resin shade on polymerization shrinkage. Materials and Methods: In this in vitro study, 14 composite discs measuring 1.5×8 mm were fabricated. The samples were prepared u...

The need for polymers for high-end applications, coupled with the desire to mimic nature's macromolecular machinery fuels the development of innovative synthetic strategies every year. The recently acquired macromolecular-synthetic tools increase the precision and enable the synthesis of polymers with high control and low dispersity. However, regardless of the specificity, the polymerization be...