scholarly journals Ranking Plasticizers for Polymers with Atomistic Simulations: PVT, Mechanical Properties, and the Role of Hydrogen Bonding in Thermoplastic Starch

2020 ◽  
Vol 2 (5) ◽  
pp. 2016-2026 ◽  
Author(s):  
Hüsamettin D. Özeren ◽  
Manon Guivier ◽  
Richard T. Olsson ◽  
Fritjof Nilsson ◽  
Mikael S. Hedenqvist
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Thermoplastic Starch ◽  
Atomistic Simulations

Computational and Experimental Study of Phenolic Resins: Thermal–Mechanical Properties and the Role of Hydrogen Bonding

2015 ◽  
Vol 48 (20) ◽  
pp. 7670-7680 ◽  
Author(s):  
Joshua D. Monk ◽  
Eric W. Bucholz ◽  
Tane Boghozian ◽  
Shantanu Deshpande ◽  
Jay Schieber ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Hydrogen Bonding ◽  
Phenolic Resins ◽  
Thermal Mechanical Properties

Mechanical Properties of Biopolymer Chains

1992 ◽  
Vol 292 ◽  
Author(s):  
Ruth Pachter ◽  
Peter D. Haaland ◽  
Robert L. Crane ◽  
W. Wade Adams
Keyword(s):  
Mechanical Properties ◽  
Amino Acids ◽  
Hydrogen Bonding ◽  
Molecular Hydrogen ◽  
Mechanical Response ◽  
Amide Bond ◽  
Pivotal Role ◽  
Helical Structures ◽  
Naturally Occurring

AbstractMolecular simulations that predict the molecular mechanical response of alpha-helical biopolymers with a reinforcing intra-molecular hydrogen bonding network, viz,, a ‘spring-like’ behavior, are presented in this study. Mechanical properties of extended biopolymer strands based on naturally occurring amino acids, namely poly(L-A1a) and for comparison poly(LGlu), versus synthetic PPTA containing an amide bond, are compared to those assuming alpha-helical structures. Thus, the pivotal role of such motifs in biological systems utilizing superior compressive mechanical properties can be inferred.

scholarly journals Deciphering the Role of π-Interactions in Polyelectrolyte Complexes Using Rationally Designed Peptides

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2074
Author(s):  
Sara Tabandeh ◽  
Cristina Elisabeth Lemus ◽  
Lorraine Leon
Keyword(s):  
Hydrogen Bonding ◽  
Phase Separation ◽  
Liquid Phase ◽  
Charge Density ◽  
Secondary Structures ◽  
Liquid Phase Separation ◽  
Polyelectrolyte Complexes ◽  
Π Interactions ◽  
Liquid Liquid Phase Separation

Electrostatic interactions, and specifically π-interactions play a significant role in the liquid-liquid phase separation of proteins and formation of membraneless organelles/or biological condensates. Sequence patterning of peptides allows creating protein-like structures and controlling the chemistry and interactions of the mimetic molecules. A library of oppositely charged polypeptides was designed and synthesized to investigate the role of π-interactions on phase separation and secondary structures of polyelectrolyte complexes. Phenylalanine was chosen as the π-containing residue and was used together with lysine or glutamic acid in the design of positively or negatively charged sequences. The effect of charge density and also the substitution of fluorine on the phenylalanine ring, known to disrupt π-interactions, were investigated. Characterization analysis using MALDI-TOF mass spectroscopy, H NMR, and circular dichroism (CD) confirmed the molecular structure and chiral pattern of peptide sequences. Despite an alternating sequence of chirality previously shown to promote liquid-liquid phase separation, complexes appeared as solid precipitates, suggesting strong interactions between the sequence pairs. The secondary structures of sequence pairs showed the formation of hydrogen-bonded structures with a β-sheet signal in FTIR spectroscopy. The presence of fluorine decreased hydrogen bonding due to its inhibitory effect on π-interactions. π-interactions resulted in enhanced stability of complexes against salt, and higher critical salt concentrations for complexes with more π-containing amino acids. Furthermore, UV-vis spectroscopy showed that sequences containing π-interactions and increased charge density encapsulated a small charged molecule with π-bonds with high efficiency. These findings highlight the interplay between ionic, hydrophobic, hydrogen bonding, and π-interactions in polyelectrolyte complex formation and enhance our understanding of phase separation phenomena in protein-like structures.

scholarly journals Study of the Preparation and Properties of TPS/PBSA/PLA Biodegradable Composites

2021 ◽  
Vol 5 (2) ◽  
pp. 48
Author(s):  
Yuxuan Wang ◽  
Yuke Zhong ◽  
Qifeng Shi ◽  
Sen Guo
Keyword(s):  
Mechanical Properties ◽  
Heat Resistance ◽  
Thermoplastic Starch ◽  
Sem Analysis ◽  
Infrared Spectrometry ◽  
Fourier Transform Infrared Spectrometry ◽  
Melt Mixing ◽  
Two Phase ◽  
Biodegradable Composites ◽  
Phase Compatibility

Thermoplastic starch/butyl glycol ester copolymer/polylactic acid (TPS/PBSA/PLA) biodegradable composites were prepared by melt-mixing. The structure, microstructure, mechanical properties and heat resistance of the TPS/PBSA/PLA composites were studied by Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), tensile test and thermogravimetry tests, respectively. The results showed that PBSA or PLA could bind to TPS by hydrogen bonding. SEM analysis showed that the composite represents an excellent dispersion and satisfied two-phase compatibility when the PLA, TPS and PBSA blended by a mass ration of 10, 30, and 60. The mechanical properties and the heat resistance of TPS/PBSA/PLA composite were improved by adding PLA with content less than 10%, according to the testing results.

Sign in / Sign up

Export Citation Format

Share Document