Characterization of HCN-Derived Thermal Polymer: Implications for Chemical Evolution

Hydrogen cyanide (HCN)-derived polymers have been recognized as sources of relevant organic molecules in prebiotic chemistry and material sciences. However, there are considerable gaps in the knowledge regarding the polymeric nature, the physicochemical properties, and the chemical pathways along polymer synthesis. HCN might have played an important role in prebiotic hydrothermal environments; however, only few experiments use cyanide species considering hydrothermal conditions. In this work, we synthesized an HCN-derived thermal polymer simulating an alkaline hydrothermal environment (i.e., HCN (l) 0.15 M, 50 h, 100 °C, pH approximately 10) and characterized its chemical structure, thermal behavior, and the hydrolysis effect. Elemental analysis and infrared spectroscopy suggest an important oxidation degree. The thermal behavior indicates that the polymer is more stable compared to other HCN-derived polymers. The mass spectrometric thermal analysis showed the gradual release of several volatile compounds along different thermal steps. The results suggest a complicate macrostructure formed by amide and hydroxyl groups, which are joined to the main reticular chain with conjugated bonds (C=O, N=O, –O–C=N). The hydrolysis treatment showed the pH conditions for the releasing of organics. The study of the synthesis of HCN-derived thermal polymers under feasible primitive hydrothermal conditions is relevant for considering hydrothermal vents as niches of chemical evolution on early Earth.

SYNTHESIS OF CROSPOVIDONE DIFFERENT PROCESS

ABSTRACT Crospovidone is a super-disintegrant and is a thermal polymer; crospovidone is a homopolymer of N-Vinyl-2- pyrrolidone; it is a random polymer of N-Vinyl-2-pyrrolidone cross-linked with (Z)-3-ethylidene-1- vinylpyrrolidone-2-one. In this article, the overview is how to synthesise crospovidone by different processes like the main theme, is direct heating of N-Vinyl-2-pyrrolidone with alkali metal hydroxides in the presence of water. Key Words: Crospovidone, Thermal Polyme

Thermal Performance on Unglazed Photovoltaic Thermal Polymer Collector

In this study, the thermal efficiency of a polymer collector with unglazed photovoltaic thermal (PVT) system was determined. Overall heat loss was estimated using the heat energy balance method. Based on the analysis, the heat removal factor of the PVT system was found to be 0.55. The thermal performance of the system was 47% during the zero reduce temperature. The unglazed PVT polymer collector could replace the conventional PVT collector, which encountered problems such as high cost, weighting issues, and corrosion.

Structural relaxation in glassy polymers predicted by soft modes: a quantitative analysis

We present a quantitative analysis of the correlation between quasi-localized, low energy vibrational modes and structural relaxation events in computer simulations of a quiescent, thermal polymer glass.