Aliphatic polyamides derived from odd diamine or odd dicarboxylic acid units cannot adopt a conventional sheet structure when molecular chains have an all trans conformation. However, typical fiber diffraction patterns of this sheet structure were observed in several polyamides derived from odd units such as nylons 65 and 56. Consequently, a new structure based on the establishment of intermole...

Aliphatic polyamides (nylons) constitute a family of polymers with outstanding properties and multiple applications. Despite the intensive research studies carried out nylons, there are still unsolved questions concerning crystallization processes, crystalline structures, polymorphic transitions, morphologies. Constrains imposed by strong intermolecular interactions affect amorphous state, rigi...

Original crystal structures of even–even polyamides are introduced. They based on twisted conformations at the amide-aliphatic part links and reminiscent pleated rippled protein sheet introduced by Pauling Corey in early 1950s. Pleated sheets chiral, made two conformational isomers. have specific X-ray diffraction “profiles”. Publications describe such profiles, indicating that both variants ex...

Abstract Nylon composites are of evolving interest due to their good strength, toughness, and low coefficient friction. Various fillers like micro- nanoparticulates metals metal compounds were used enhance the mechanical tribological properties nylons for many years by researchers. In this paper, an overall understanding composites, filler materials, especially particulate application areas pol...

5-Hydroxymethylfurfural (HMF) is a platform chemical that can be produced from renewable carbohydrate sources. HMF can be converted to 1,2,4-benzenetriol (BTO) which after catalytic hydrodeoxygenation provides a route to cyclohexanone and cyclohexanol. This mixture, known as KA oil, is an important feedstock for polymeric products such as nylons which use benzene as feedstock that is obtained f...

Pleated and rippled sheet crystal structures of even–even nylons that feature twisted amide group–aliphatic part links were introduced in the previous contribution (Macromolecules, 2021, 54, DOI: 10.1021/acs.macromol.0c02404). sheets are made isochiral conformational isomeric stems, racemic stereocomplexes enantiomeric stem conformations. These models used to reanalyze various puzzling manifest...