Search

Print inks have assumed an important role on finished materials, such as plastic packages, which can have a long lifetime when disposed as municipal waste. By this way, it is important to evaluate the influence of physical parameters on the degradation of shot lifetime substrates covered by pigmented print inks cured by UV radiation. [ABSTRACT FROM AUTHOR]

Plastics have been used in short-life products, which have presented harmful consequences for the nature, because of the low degradation rate reached by the most common polyolefins. This work evaluates the mechanical and thermal properties of pure iPP, plasticized starch (TPS) with biodiesel (TPSBio) or commercial (TPSCom) glycerols, and their blends (iPP/TPSPlas). The addition of TPSPlas caused an increasing on the cristallinity of iPP, mainly for the compositions 90/10 and 80/20, probably due to morphological alterations such as crosslinking, that may have modified the molecular arrangement of the iPP in the presence of glycerol. [ABSTRACT FROM AUTHOR]

Hydrogels, in general, can be used as a compliant surface in prosthesis of human synovial joints due to their biocompatible characteristics. In this work, different hydrogels were prepared from two aqueous solutions of PVAL (15 and 20 mass/mass%) by chemical reactions using citric acid as a cross-linking agent and by electron beam (EB) irradiation with doses from 25 to 100 kGy. The hydrogels were evaluated by their mechanical properties through indentation creep test, thermal properties by differential scanning calorimetry (DSC), and also equilibrium water content (EWC). [ABSTRACT FROM AUTHOR]

Radiation curing is an environmentally-friendly technology. Furthermore, radiation curing is a faster, energy saving and more efficient industrial process than the heat-curable process. One of the most important requirements for the widespread application of UV curable coatings in the coating industry is that they are stable vs. atmospheric degradation. Today's state of the art in oxidative drying and thermosetting coatings is the use of light stabilizers to protect polymers vs. the damage of outdoor exposure. Oxygen has a detrimental effect on the cure response of free radical systems, especially in thin-film coatings. Differential photocalorimetry (photo-DSC) was used to investigate the oxygen effect and the use of light stabilizers on UV curing of photocurable formulations based on acrylate materials. Coating thickness influence was also considered. [ABSTRACT FROM AUTHOR]