Microphase Separation Induced by Hydrogen Bonding in a Poly(1,4-butadiene)-block-poly(1,4-isoprene) Diblock CopolymerAn Example of Supramolecular Organization via Tandem Interactions

1998 ◽  
Vol 31 (10) ◽  
pp. 3379-3382 ◽  
Author(s):  
Liane de Lucca Freitas ◽  
Marly M. Jacobi ◽  
Giovane Gonçalves ◽  
Reimund Stadler
Keyword(s):  
Hydrogen Bonding ◽  
Microphase Separation ◽  
Supramolecular Organization

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.

Combinations of Microphase Separation and Terminal Multiple Hydrogen Bonding in Novel Macromolecules

2002 ◽  
Vol 124 (29) ◽  
pp. 8599-8604 ◽  
Author(s):  
Koji Yamauchi ◽  
Jeremy R. Lizotte ◽  
David M. Hercules ◽  
Matthew J. Vergne ◽  
Timothy E. Long
Keyword(s):  
Hydrogen Bonding ◽  
Microphase Separation ◽  
Multiple Hydrogen Bonding

Preparation of polyurethanes with broad damping temperature range and self-healing properties

2019 ◽  
Vol 52 (5) ◽  
pp. 410-431 ◽  
Author(s):  
Xun Lu ◽  
Min Xu ◽  
Ye-ming Sheng ◽  
Zhi-peng Li ◽  
Han-mo Li
Keyword(s):  
Hydrogen Bonding ◽  
Synergistic Effect ◽  
Microphase Separation ◽  
Monomethyl Ether ◽  
Self Healing ◽  
Temperature Range ◽  
Healing Property ◽  
Tan Δ ◽  
C 50 ◽  
Damping Materials

It is urgent for polyurethane (PU) damping materials to broaden the effective damping range. Based on the designability of PU, this study is focused on the role of long dangling chain, wherein prepared by the reaction of polyethylene glycol monomethyl ether with toluene-2,4-diisocyanate. Notably, the introduction of long dangling chain not only makes the dangling chain longer and enhances the intermolecular interaction but also equips the dangling chain with strong polar carbamate group, bringing about more excellent compatibility of the soft and hard segments and lower degree of microphase separation under the condition of hydrogen bonding. The results show that the damping performance increases with the synergistic effect of significant hydrogen bonding and decreased degree of microphase separation, and the effective damping temperature range (tan δ ≥ 0.3) can exceed 150°C (−50°C to 100°C). Simultaneously, the addition of long dangling chains endows PU with self-healing property, the self-healing rate of system reaches maximum 70% with shore A hardness of 15 because of the synergistic effect above with the addition of 60% dangling chain, which extends the service life of PU damping materials.

Thermoreversible Crosslinking of Maleated Ethylene/Propylene Rubber Using Ionic Interactions, Hydrogen Bonding and a Combination Thereof

2008 ◽  
Vol 81 (1) ◽  
pp. 96-109 ◽  
Author(s):  
M. A. J. van der Mee ◽  
J. G. P. Goossens ◽  
M. van Duin
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Room Temperature ◽  
Microphase Separation ◽  
Distinct Advantage ◽  
Ionic Interactions ◽  
Ethylene Propylene ◽  
Bonded Materials ◽  
Compression Set ◽  
High Degree

Abstract Maleated ethylene/propylene copolymer (MAn-g-EPM) was thermoreversibly crosslinked using different routes, i.e. ionic interactions (ionomers), hydrogen bonding and a combination thereof. Microphase separation into polar MAn-rich aggregates occurs for MAn-g-EPM and all crosslinked materials, which act as physical crosslinks. The crosslink density does not change upon modification, but the strength of the aggregates is significantly increased, resulting in improved mechanical properties. All materials except the potassium ionomer with high degree of neutralization (DN) could be remolded into homogeneous and smooth films without chemical changes, indicating that the crosslinks are truly thermoreversible. A comparison of the mechanical properties, i.e. tensile properties and compression set at room temperature, for the different crosslinking routes showed that the poorest properties are obtained for hydrogen-bonded materials. The potassium ionomer with high DN has the best properties by far, but is difficult to process. Comparable mechanical properties are obtained for zinc ionomers, potassium ionomers with low DN and amide-salts, which combine ionic interactions and hydrogen bonding. The amide-salts have a distinct advantage in processing over the ionomers, since they can be compression molded at much lower temperatures, although high temperatures should be avoided because of irreversible imide formation.

scholarly journals Microphase separation induced in the melt of Pluronic copolymers by blending with a hydrogen bonding urea–urethane end-capped supramolecular polymer

Soft Matter ◽  
2015 ◽  
Vol 11 (29) ◽  
pp. 5799-5803 ◽  
Author(s):  
Daniel Hermida-Merino ◽  
Gemma E. Newby ◽  
Ian W. Hamley ◽  
Wayne Hayes ◽  
Andrew Slark
Keyword(s):  
Hydrogen Bonding ◽  
Microphase Separation ◽  
Supramolecular Polymer
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