Valorization of the Isocyanate-Derived Fraction from Polyurethane Glycolysis by Synthesizing Polyureas and Polyamides.

The isocyanate-derived fraction resulting as the bottom phase from the split-phase glycolysis of conventional polyurethane flexible foams has been given a new life based on the formation of amine-based polymers (polyureas and polyamides). For that purpose, the bottom phase was first hydrolyzed, producing toluenediamine and diethylene glycol, and further subjected to controlled vacuum distillation in order to recover both products separately. The hydrolysis reaction and the separation process conditions were determined and optimized, obtaining products with a purity comparable to that of commercial ones.

Polyurethane Composites Recycling with Styrene-Acrylonitrile and Calcium Carbonate Recovery.

The glycolysis process of flexible polyurethane foams containing styrene-acrylonitrile and calcium carbonate as fillers was explored in detail. The use of DABCO as a catalyst allowed us to reduce the catalyst concentration and the polyurethane-to-glycol mass ratio to 0.1% and 1:1, respectively.

Crosslinked Bifunctional Particles for the Removal of Bilirubin in Hyperbilirubinemia Cases.

This work describes the development of styrene-divinylbenzene (St-DVB) particles with polyethylene glycol methacrylate (PEGMA) and/or glycidyl methacrylate (GMA) brushes for the removal of bilirubin from blood in haemodialyzed patients. Bovine serum albumin (BSA) was immobilized onto the particles using ethyl lactate as a biocompatible solvent, which allowed the immobilization of up to 2 mg BSA/g of particles. The presence of albumin on the particles increased their capacity for bilirubin removal from phosphate-buffered saline (PBS) by 43% compared to particles without albumin.

Functionalization of Poly(styrene-co-methyl methacrylate) Particles for Selective Removal of Bilirubin.

Hyperbilirubinemia is one of the main causes of death in patients with severe hepatic problems, which justifies the research for bilirubin removal solutions. In this study, St-MMA particles with PEGMA and/or GMA brushes were synthesized. First, the recipe for St-MMA was optimized and then adapted for PEGMA and GMA incorporation.

Effect of Foaming Formulation and Operating Pressure on Thermoregulating Polyurethane Foams.

The synthesis of rigid polyurethane (RPU) foams containing thermoregulatory microcapsules has been carried out under reduced pressure conditions with a new foaming formulation to reduce the final composite densities. These optimized RPU foams were able to overpass the drawbacks exhibited by the previous composites over the studied temperature range, working as insulating and thermal energy storage materials. The change in the formulation allowed to decrease the final foam density and enhance their mechanical strength.

Glycolysis of Polyurethanes Composites Containing Nanosilica.

Rigid polyurethane (RPU) foams have been successfully glycolyzed by using diethylene glycol (DEG) and crude glycerol (CG) as transesterification agents. However, DEG did not allow to achieve a split-phase process, obtaining a product with low polyol purity (61.7 wt %).

Improving the Hydrophilicity of Flexible Polyurethane Foams with Sodium Acrylate Polymer.

Hydrophilic, flexible polyurethane (FPU) foams made from Hypol prepolymers are capable of retaining large amounts of water and saline solutions. The addition of different catalysts and surfactant agents to Hypol JM 5008 prepolymer was assayed to obtain a foam with good structural stability and elasticity. The combination of three catalysts, stannous octoate and two amine-based ones (Tegoamin 33 and Tegoamin BDE), and the surfactant Niax silicone L-620LV allowed to synthesize a foam with a homogeneous cell size distribution, exhibiting the highest saline absorption capacity (2.

Diffusion of Shape Stabilized PEG-SiO as a Driver for Producing Thermoregulating Facing Bricks.

A novel form-stable phase-change material (PCM) based on facing bricks was developed by incorporating thermoregulating PEG-SiO, synthetized by sol-gel method and based on polyethylene glycol as phase-change material and silica as stabilizer compound. The PEG-SiO in its liquid form () is firstly adsorbed inside the porous brick and lastly stabilized () by controlling its gelation time, obtaining form-stable PCMs with PEG-SiO contents within 15-110 wt.%.

The role of native lichens in the biomonitoring of gaseous mercury at contaminated sites.

Contamination by atmospheric mercury has been assessed in two different areas from Spain (Las Cuevas, Ciudad Real and Flix, Tarragona) using lichens as biomonitors. The relationship established between mercury contents in the soils and the gaseous mercury (GM) was also observed. It was found that the GM is highest in the vicinity of the source and it is dispersed depending on of the distance to the source and the wind directions.

Synthesis of microcapsules containing different extractant agents.

Mercury is one of the most toxic pollutants, with high capacity of accumulation in living organism, causing important human health problems. Therefore, the mercury removal from water is an important research goal. In a previous work, an extractant agent [di(2-ethylhexyl)phosphoric acid] was microencapsulated in poly(styrene-co-divinylbenzene) by means of suspension polymerisation using toluene as diluent.