Rigid semi-Interpenetrated Polymer Network (semi-IPN) foam based on poly(vinyl chloride) (PVC) and crosslinked polyurea/isocyanurate are complex materials that at present are not recyclable. They are used in many fields, including wind blade cores. In this work we studied the depolymerization of the crosslinked portion of the foam under glycolysis conditions for the separation and reuse of the individual components.
View Article and Find Full Text PDFIn this work, the rheological behavior of stable poly(lactic acid) (PLA) dispersions in water, intended for coating applications, was investigated. The newly prepared dispersion consists of PLA particles with an average diameter of 222 ± 2 nm based on dynamic light scattering (DLS) and scanning electron microscopy (SEM) analyses, at concentrations varying in the 5-22 wt % range. Xanthan gum (XG), a bacterial polysaccharide, was used as a thickening agent to modulate the viscosity of the formulations.
View Article and Find Full Text PDFA green, effective methodology for the preparation of water-based dispersions of poly(lactic acid) (PLA) for coating purposes is herein presented. The procedure consists of two steps: in the first one, an oil-in-water emulsion is obtained by mixing a solution of PLA in ethyl acetate with a water phase containing surfactant and stabilizer. Different homogenization methods as well as oil/water phase ratio, surfactant and stabilizer combinations were screened.
View Article and Find Full Text PDFThe polycondensation of diamines and dialdehydes promoted by an N-heterocyclic carbene (NHC) catalyst in the presence of a quinone oxidant and hexafluoro-2-propanol (HFIP) is herein presented for the synthesis of oligomeric polyamides (PAs), which are obtained with a number-average molecular weight (M ) in the range of 1.7-3.6 kg mol as determined by NMR analysis.
View Article and Find Full Text PDFA novel vinylogous aldol addition of alkylidene oxindole with 1-trifluoromethyl-3-alkylidene-propan-2-ones is presented. The reaction, catalyzed by a bifunctional tertiary amine, provides an efficient application of the vinylogous reactivity of oxindoles for the preparation of enantioenriched trifluoromethylated allylic alcohols.
View Article and Find Full Text PDFBackground: Patients are showing an increasing interest in the use of complementary and alternative medicine (CAM). Most nurses are open to the adoption of CAM into clinical nursing practice, but they may experience a lack of knowledge about the safe and effective use of these therapies. Several studies concerning nurses' knowledge and attitudes toward CAM have been published, but only in one, the authors (Shorofi and Arbon) used a validated questionnaire.
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