scholarly journals Quadruple Hydrogen Bond-Containing A-AB-A Triblock Copolymers: Probing the Influence of Hydrogen Bonding in the Central Block

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4705
Author(s):  
Boer Liu ◽  
Xi Chen ◽  
Glenn A. Spiering ◽  
Robert B. Moore ◽  
Timothy E. Long
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Microphase Separation ◽  
Triblock Copolymers ◽  
Random Copolymer ◽  
Thermomechanical Properties ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Central Block ◽  
Quadruple Hydrogen Bonding

This work reveals the influence of pendant hydrogen bonding strength and distribution on self-assembly and the resulting thermomechanical properties of A-AB-A triblock copolymers. Reversible addition-fragmentation chain transfer polymerization afforded a library of A-AB-A acrylic triblock copolymers, wherein the A unit contained cytosine acrylate (CyA) or post-functionalized ureido cytosine acrylate (UCyA) and the B unit consisted of n-butyl acrylate (nBA). Differential scanning calorimetry revealed two glass transition temperatures, suggesting microphase-separation in the A-AB-A triblock copolymers. Thermomechanical and morphological analysis revealed the effects of hydrogen bonding distribution and strength on the self-assembly and microphase-separated morphology. Dynamic mechanical analysis showed multiple tan delta (δ) transitions that correlated to chain relaxation and hydrogen bonding dissociation, further confirming the microphase-separated structure. In addition, UCyA triblock copolymers possessed an extended modulus plateau versus temperature compared to the CyA analogs due to the stronger association of quadruple hydrogen bonding. CyA triblock copolymers exhibited a cylindrical microphase-separated morphology according to small-angle X-ray scattering. In contrast, UCyA triblock copolymers lacked long-range ordering due to hydrogen bonding induced phase mixing. The incorporation of UCyA into the soft central block resulted in improved tensile strength, extensibility, and toughness compared to the AB random copolymer and A-B-A triblock copolymer comparisons. This study provides insight into the structure-property relationships of A-AB-A supramolecular triblock copolymers that result from tunable association strengths.

Self-Assembly of Hydrogels From Elastin-Mimetic Block Copolymers

2002 ◽  
Vol 724 ◽  
Author(s):  
Elizabeth R. Wright ◽  
R. Andrew McMillan ◽  
Alan Cooper ◽  
Robert P. Apkarian ◽  
Vincent P. Conticello
Keyword(s):  
Block Copolymers ◽  
Self Assembly ◽  
Triblock Copolymers ◽  
Variable Temperature ◽  
Inverse Temperature ◽  
Temperature Transition ◽  
Scanning Calorimetry ◽  
Design Synthesis ◽  
Inverse Temperature Transition ◽  
Functional Biomaterials

AbstractTriblock copolymers have traditionally been synthesized with conventional organic components. However, triblock copolymers could be synthesized by the incorporation of two incompatible protein-based polymers. The polypeptides would differ in their hydrophobicity and confer unique physiochemical properties to the resultant materials. One protein-based polymer, based on a sequence of native elastin, that has been utilized in the synthesis of biomaterials is poly (Valine-Proline-Glycine-ValineGlycine) or poly(VPGVG) [1]. This polypeptide has been shown to have an inverse temperature transition that can be adjusted by non-conservative amino acid substitutions in the fourth position [2]. By combining polypeptide blocks with different inverse temperature transition values due to hydrophobicity differences, we expect to produce amphiphilic polypeptides capable of self-assembly into hydrogels. Our research examines the design, synthesis and characterization of elastin-mimetic block copolymers as functional biomaterials. The methods that are used for the characterization include variable temperature 1D and 2D High-Resolution-NMR, cryo-High Resolutions Scanning Electron Microscopy and Differential Scanning Calorimetry.

Hydrogen-Bonding Mediated Self-Assembly of Amphiphilic ABA Triblock Copolymers into Well-Defined Giant Vesicles

2021 ◽  
Author(s):  
Huiying Wang ◽  
Qiang Chen ◽  
Zhen Geng ◽  
Jingyi Rao ◽  
Bijin Xiong ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Triblock Copolymers ◽  
Giant Vesicles

Giant vesicles represent an extremely useful system to mimick biomembranes; however, available methodologies towards easy and direct vesicles construction are still scarce. By designing a hydrogen-bonding (H-bonding) amphiphilic ABA triblock...

Self-Assembly Behavior of A-B Diblock and C-D Random Copolymer Mixtures in the Solution State through Mediated Hydrogen Bonding

Langmuir ◽  
2008 ◽  
Vol 24 (15) ◽  
pp. 7727-7734 ◽  
Author(s):  
Chih-Hao Hsu ◽  
Shiao-Wei Kuo ◽  
Jem-Kun Chen ◽  
Fu-Hsiang Ko ◽  
Chun-Syong Liao ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Random Copolymer ◽  
Solution State ◽  
Assembly Behavior

scholarly journals Measurements, Thermodynamic Modeling, and a Hydrogen Bonding Study on the Solubilities of Metoprolol Succinate in Organic Solvents

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2469 ◽  
Author(s):  
Jian Shen ◽  
Xianrui Liang ◽  
Hao Lei
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bonding ◽  
Ethyl Acetate ◽  
Density Functional ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Fixed Temperature ◽  
Functional Theory ◽  
Metoprolol Succinate ◽  
Bonding Structure

The solubilities of metoprolol succinate (a cardioselective β1 adrenergic receptor) in methanol, ethanol, n-propanol, isopropanol, n-butanol, ethyl acetate, and acetone were measured at temperatures ranging from (278.2 to 318.2) K using a solid–liquid equilibrium method. The solubility of metoprolol succinate increases with increasing temperature. At a fixed temperature, the solubility decreases in the order methanol > ethanol > n-butanol > n-propanol > isopropanol > acetone > ethyl acetate. The enthalpy of fusion and the melting point of metoprolol succinate were determined by differential scanning calorimetry. The thermodynamic properties of the dissolution process, determined by a van’t Hoff analysis, have been obtained and are discussed. The modified Apelblat equation, Wilson model, and non-random two-liquid (NRTL) model were employed to correlate the solubilities of metoprolol succinate in different solvents. Finally, a quantitative structure–property relationship (QSPR) study of physical properties of solvents and density functional theory simulations of hydrogen-bonding structure were carried out to give the explanation for the sequence of solubility in alcohols. The density functional theory (DFT) calculations well illustrated that the solubility of metoprolol succinate in various alcohols can be mainly attributed to the intra- and intermolecular hydrogen bonds in metoprolol succinate-solvent complexes.

Synthesis of urea-containing ABA triblock copolymers: Influence of pendant hydrogen bonding on morphology and thermomechanical properties

2018 ◽  
Vol 56 (16) ◽  
pp. 1844-1852
Author(s):  
Mingtao Chen ◽  
David L. Inglefield ◽  
Keren Zhang ◽  
Amanda G. Hudson ◽  
Samantha J. Talley ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Triblock Copolymers ◽  
Thermomechanical Properties

scholarly journals Nucleobase-functionalized ABC triblock copolymers: self-assembly of supramolecular architectures

2014 ◽  
Vol 50 (65) ◽  
pp. 9145-9148 ◽  
Author(s):  
Keren Zhang ◽  
Gregory B. Fahs ◽  
Motohiro Aiba ◽  
Robert B. Moore ◽  
Timothy E. Long
Keyword(s):  
Self Assembly ◽  
Triblock Copolymers ◽  
Raft Polymerization ◽  
Abc Triblock Copolymers ◽  
Central Block ◽  
Supramolecular Architectures

RAFT polymerization afforded acrylic ABC triblock copolymers with self-complementary nucleobase-functionalized external blocks and a low-Tg soft central block.

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