International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Polyurethanes generally have low thermal stability and thermal degradation can occur during exploitation above 180 °C. It is assessed that the modification of the polyurethane chains via forming thermally stable permanent heterocyclic structures can improve the thermal stability. Polyurethane foams based on networks with isocyanurate rings are generally insulation-grade and have excellent thermal stability. In order to assess a quantitative contribution of pendant chains, polyurethane soft elastomers based with a controlled architecture were synthesized by prepolymer procedure. A simple strategy was developed to prepare networks based on poly(oxypropylene)diol and 2,4-TDI by adding the monofunctional component for prepolymer synthesis. Network formation was described using the cascade theory. Mechanical properties were determined from stress-strain experiments. It was estimated that the increase of the monool in the precursor formulation influenced the increase of energy at break and the elongation but affected to decrease of Young modulus.

Advances in technology since the second half of the 20th century are followed as well as induced by the development of intelligent materials. These materials are able to respond to external stimuli by measurable changes in structure and intrinsic properties. Stimuli-responsive hydrogels are soft smart materials as they exhibit significant changes in physicochemical properties in response to small external stimuli. Acrylate hydrogels are widely used in applications where their smart and soft nature comes to the fore. Synthesis of those materials by conventional heating is time-consuming and unsuitable from the point of energy and sources saving. Microwave-assisted synthesis is promising method that provides polymerization under the more favourable conditions, reducing the reaction time. The focus of present work was to investigate the swelling behaviour, mechanical and thermal properties of acrylate hydrogels synthesized by microwave heating.