Structure and Mechanical Properties of Rubberlike Proteins in Animals

1987 ◽  
Vol 60 (3) ◽  
pp. 417-438 ◽  
Author(s):  
John M. Gosline
Keyword(s):  
Amorphous Polymer ◽  
Polymer Networks ◽  
Random Coil ◽  
Future Research ◽  
Random Networks ◽  
Glass Transitions ◽  
Mechanical State ◽  
Protein Molecules ◽  
Polypeptide Chains ◽  
Covalent Crosslinks

Abstract Polymer networks formed from protein molecules that adopt kinetically-free, random-coil conformations are found in many animals, where they play a number of important roles. The 5 rubberlike proteins isolated and studied to date indicate that animal rubbers, like their synthetic counterparts, contain random networks which are usually stabilized by covalent crosslinks. Long-range elasticity in rubberlike proteins is based on changes in the conformational entropy of random-coil molecules. Further, these protein networks show viscoelastic glass transitions similar to all other amorphous polymer networks. Future research on protein sequences should increase our understanding of how polypeptide chains can function as random-coil molecules, and studies into the mechanical state of elastin in arterial tissues may provide important clues about the mechanisms of some forms of human disease.

Ability to Control the Glass Transition Temperature of Amorphous Shape-Memory Polyesterurethane Networks by Varying Prepolymers in Molecular Mass as well as in Type and Content of Incorporated Comonomers

2009 ◽  
Vol 1190 ◽  
Author(s):  
Joerg Zotzmann ◽  
Steffen Kelch ◽  
Armin Alteheld ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Glass Transition ◽  
Minimally Invasive Surgery ◽  
Shape Memory ◽  
Molecular Mass ◽  
Amorphous Polymer ◽  
Polymer Networks ◽  
Precise Control ◽  
Low Weight ◽  
Switching Temperature ◽  
Selection Of

AbstractThe need of intelligent implant materials for applications in the area of minimally invasive surgery leads to tremendous attention for polymers which combine degradability and shape-memory capability. Application of heat, and thereby exceeding a certain switching temperature Tsw, causes the device to changes its shape. The precise control of Tsw is particularly challenging. It was investigated in how far Tg, that can be used as Tsw, of amorphous polymer networks from star-shaped polyester macrotetrols crosslinked with a low-weight linker can be controlled systematically by incorporation of different comonomers into poly(rac-lactide) prepolymers. The molecular mass of the prepolymers as well as type and content of the comonomers was varied. The Tg could be adjusted by selection of comonomer type and ratio without affecting the advantageous elastic properties of the polymer networks.

Glass transitions of topologically interpenetrating polymer networks

1974 ◽  
Vol 14 (9) ◽  
pp. 646-650 ◽  
Author(s):  
H. L. Frisch ◽  
K. C. Frisch ◽  
D. Klempner
Keyword(s):  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Glass Transitions

scholarly journals Conversion of amorphous polymer networks to covalent organic frameworks under ionothermal conditions: a facile synthesis route for covalent triazine frameworks

2015 ◽  
Vol 3 (48) ◽  
pp. 24422-24427 ◽  
Author(s):  
Sophie Kuecken ◽  
Johannes Schmidt ◽  
Linjie Zhi ◽  
Arne Thomas
Keyword(s):  
Amorphous Polymer ◽  
Polymer Networks ◽  
Porous Polymer ◽  
Covalent Organic Frameworks ◽  
Facile Synthesis ◽  
Synthesis Route

Covalent triazine frameworks (CTFs) are prepared from amorphous, non-porous polymer networks using a facile and scalable procedure.

scholarly journals High-Abundance Polypeptides of the Human Plasma Proteome Comprising the Top 4 Logs of Polypeptide Abundance

2008 ◽  
Vol 54 (10) ◽  
pp. 1608-1616 ◽  
Author(s):  
Glen L Hortin ◽  
Denis Sviridov ◽  
N Leigh Anderson
Keyword(s):  
Plasma Proteins ◽  
Clinical Laboratory ◽  
Plasma Concentrations ◽  
High Abundance ◽  
Molar Basis ◽  
Protein Molecules ◽  
Polypeptide Chains ◽  
Peptide Segments ◽  
Human Plasma Proteome ◽  
Individual Peptide

Abstract Background: Plasma contains thousands of proteins, but a small number of these proteins comprise the majority of protein molecules and mass. Content: We surveyed proteomic studies to identify candidates for high-abundance polypeptide chains. We searched the literature for information on the plasma concentrations of the most abundant components in healthy adults and for the molecular mass of the mature polypeptide chains in plasma. Because proteomic studies usually dissociate proteins into polypeptide chains or detect short peptide segments of proteins, we summarized data on individual peptide chains for proteins containing multiple subunits or polypeptides. We collected data on about 150 of the most abundant polypeptides in plasma. The abundant polypeptides span approximately the top 4 logs of concentration in plasma, from 650 to 0.06 μmol/L on a molar basis or from about 50 000 to 1 mg/L mass abundance. Conclusions: Data on the concentrations of the high-abundance peptide chains in plasma assist in understanding the composition of plasma and potential approaches for clinical laboratory or proteomic analysis of plasma proteins. Development of more extensive databases regarding the plasma concentrations of proteins in health and diseases would promote diagnostic and proteomic advances.

scholarly journals Effects of Moisture on Diffusion in Unmodified Wood Cell Walls: A Phenomenological Polymer Science Approach

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1084 ◽  
Author(s):  
Joseph E. Jakes ◽  
Christopher G. Hunt ◽  
Samuel L. Zelinka ◽  
Peter N. Ciesielski ◽  
Nayomi Z. Plaza
Keyword(s):  
Cell Wall ◽  
Polymer Matrix ◽  
Cell Walls ◽  
Glassy State ◽  
Solid Polymer ◽  
Future Research ◽  
Polymer Science ◽  
Glass Transitions ◽  
The Hierarchical Structure ◽  
Unmodified Wood

Despite the importance of cell wall diffusion to nearly all aspects of wood utilization, diffusion mechanisms and the detailed effects of moisture remain poorly understood. In this perspective, we introduce and employ approaches established in polymer science to develop a phenomenological framework for understanding the effects of moisture on diffusion in unmodified wood cell walls. The premise for applying this polymer-science-based approach to wood is that wood polymers (cellulose, hemicelluloses, and lignin) behave like typical solid polymers. Therefore, the movement of chemicals through wood cell walls is a diffusion process through a solid polymer, which is in contrast to previous assertions that transport of some chemicals occurs via aqueous pathways in the cell wall layers. Diffusion in polymers depends on the interrelations between free volume in the polymer matrix, molecular motions of the polymer, diffusant dimensions, and solubility of the diffusant in the polymer matrix. Because diffusion strongly depends on whether a polymer is in a rigid glassy state or soft rubbery state, it is important to understand glass transitions in the amorphous wood polymers. Through a review and analysis of available literature, we conclude that in wood both lignin and the amorphous polysaccharides very likely have glass transitions. After developing and presenting this polymer-science-based perspective of diffusion through unmodified wood cell walls, suggested directions for future research are discussed. A key consideration is that a large difference between diffusion through wood polymers and typical polymers is the high swelling pressures that can develop in unmodified wood cell walls. This pressure likely arises from the hierarchical structure of wood and should be taken into consideration in the development of predictive models for diffusion in unmodified wood cell walls.

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