Prolonged Thermal Relaxation of the Thermosetting Polymers

The rigidity of structures made of polymer composite materials, operated at elevated temperatures, is mainly determined by the residual rigidity of the polymer binder (which is very sensitive to elevated temperatures); therefore, the study of ways to increase the rigidity of polymer materials under heating (including prolonged heating) is relevant. In the previous research, cured thermosetting polymer structure’s non-stability, especially under heating, is determined by its supra-molecular structure domain’s conglomerate character and the high entropy of such structures. The polymer elasticity modeling proved the significance of the entropy factor and layer (EPL) model application. The prolonged heating makes it possible to release adsorptive inter-layer bonds and volatile groups. As a result, the polymer structure is changing, and inner stress relaxation occurs due to this thermo-process, called thermo-relaxation. The present study suggests researching thermo-relaxation’s influence on polymers’ deformability under load and heating. The research results prove the significant polymer structure modification due to thermo-relaxation, with the polymer entropy parameter decreasing, the glassing onset temperature point (Tg) increasing by 1.3–1.7 times, and the modulus of elasticity under heating increasing by 1.5–2 times.

Epoch-Making Discovery for CO2 Characteristics: “Pseudo Osmosis” in the Gas Phase

Recently, unprecedented torrential rains have deluged the globe, resulting in disastrous floods. These disasters were caused by climate changes because of an increase in carbon dioxide (CO2) concentration in the atmosphere since the industrial revolution. Therefore, atmospheric accumulation of CO2 should be reduced to avoid a future climate crisis. Many methods to fix CO2 have been developed, but a practical method has not been established, except for the method using amines based on moderate plant constructions. However, the membrane method has not yet been established because of the conflicting relationship between penetrability and specificity, although membrane technology can be used for CO2 separation. Epoch-making discoveries for CO2 characteristics have been presented as follows: 1) the high penetrability of CO2 in the gas phase caused “pursued osmosis” against polymer elasticity; 2) highly penetrable CO2 passed through polymer membranes such as authentic polymers and natural cellulose, whereas neither O2 nor N2 penetrates these polymers examined; 3) CO2 is absorbed by plastics; 4) H2 and CH4 gases penetrate through polymer membranes, but their penetration was completely blocked in the presence of water; and 5) using a polytunnel made of polymer sheets (an artificial forest or positive green house), which allows CO2 penetration, instead of hard chamber, steel, or plastic could be cost effective. Therefore, polymer membranes could be practically and economically useful for CO2 separation from the exhaust gas and atmosphere.

Preparation and Research Progress of Polymer-based Flexible Conductive Composites

The development of flexible wearable electronic devices is one of the future directions of technology development. Flexible conductive materials are important supporting materials for wearable electronic devices. Polymer has excellent flexibility, it is an important way to prepare flexible conductor from polymer-based conductive composites. In this paper, the research progress of polymer-based flexible conductive composites is summarized from the aspects of preparation and characterization methods. The key factors to realize flexible conductor are put forward, namely, the maintenance of excellent polymer elasticity and the realization of stable. The design and preparation of the extensible conductor with high elasticity matrix and nanofiller are introduced in detail, and the problems in the current research are summarized.