Hydrogen-Bonding Interactions in Hard Segments of Shape Memory Polyurethane: Toluene Diisocyanates and 1,6-Hexamethylene Diisocyanate. A Theoretical and Comparative Study

2014 ◽  
Vol 118 (51) ◽  
pp. 12241-12255 ◽  
Author(s):  
Cuili Zhang ◽  
Jinlian Hu ◽  
Xun Li ◽  
You Wu ◽  
Jianping Han
Keyword(s):  
Hydrogen Bonding ◽  
Comparative Study ◽  
Shape Memory ◽  
Hexamethylene Diisocyanate ◽  
Hydrogen Bonding Interactions ◽  
Hard Segments ◽  
Shape Memory Polyurethane

Mechanically strong and resilient shape memory polyurethane with hexamethylene diisocyanate as mixing segment

2020 ◽  
pp. 1045389X2096606
Author(s):  
Jayashree Mohanty ◽  
Hema Garg ◽  
Priyanka Gupta ◽  
Ramasamy Alagirusamy ◽  
Bijay P Tripathi ◽  
...  
Keyword(s):  
Shape Memory ◽  
Soft Segment ◽  
Linear Chain ◽  
Maxwell Model ◽  
Hexamethylene Diisocyanate ◽  
Chain Flexibility ◽  
Elongation At Break ◽  
Entropic Elasticity ◽  
Hard Segments ◽  
Shape Memory Polyurethane

Mechanical robustness and flexibility of shape memory polyurethane (SMPU) make them a prominent candidate in various field. However, the shape memory characteristics are hampered due to the lower breaking stress and strain originating from the slippage of hard segments during deformation and entropic elasticity of the segments. Herein, SMPU is synthesised by modification of Polycaprolactone diol (PCL) based soft segment by introducing a linear chain diisocyante, that is hexamethylene diisocyanate (HDI) as the mixing segment and rigid MDI (4,4′-methylene bis-phenyl diisocyanate) as the hard segment. The HDI based soft segment is expected to improve the chain flexibility, and MDI will retain the strength factor. The SMPU is characterised by chemical, structural and thermal analysis. The stress relaxation behaviour of the film was analysed w.r.t time and correlated with recovery studies using the Maxwell model. The thermomechanical conditions are optimised to attain higher shape fixity (SF) and shape recovery (SR) and the SMPU shows maximum SF (60.8%) and SR (97%) at 70°C temperature and 50% strain condition. Also, SMPU shows the tensile strength of 23.4 MPa with elongation at break of nearly 1270%. Thus, the combination of both diisocyanate and soft segments imparts strength and ductility to the SMPU.

Viscoelastic Behavior of Segmented Elastomers

1967 ◽  
Vol 40 (4) ◽  
pp. 1105-1110 ◽  
Author(s):  
Stuart L. Cooper ◽  
Arthur V. Tobolsky
Keyword(s):  
Hydrogen Bonding ◽  
Glass Transition ◽  
High Temperature ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Viscoelastic Behavior ◽  
Temperature Transition ◽  
Hydrogen Bonding Interactions ◽  
Structural Nature ◽  
Hard Segments

Abstract Viscoelastic behavior of linear segmented elastomers was examined. The unusual properties found in spandex systems are also observable in hydrocarbon block co-polymers, indicating that hydrogen bonding interactions are perhaps not essential. Low temperature properties of segmented systems are governed by the structural nature of the associated flexible segments, which determines the value of the major glass transition temperature (Tg). It appears that an association of the hard segments provides a broad temperature range of enhanced rubbery modulus. This occurs between the major Tg and a secondary high temperature transition.

Comparative study of hydrogen-bonding interactions between cis-proline analogs and solvents

2019 ◽  
Vol 280 ◽  
pp. 205-211 ◽  
Author(s):  
Fang Yu ◽  
Geng Deng ◽  
Zonghua Wang ◽  
Shida Gong ◽  
Xianzhen Xu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Comparative Study ◽  
Hydrogen Bonding Interactions

scholarly journals Shape Memory Polyurethane and its Composites for Various Applications

2019 ◽  
Vol 9 (21) ◽  
pp. 4694 ◽  
Author(s):  
Arvind Gupta ◽  
Anoth Maharjan ◽  
Beom Soo Kim
Keyword(s):  
Tissue Engineering ◽  
Literature Review ◽  
Shape Memory ◽  
Electromagnetic Interference ◽  
Unique Property ◽  
Potential Candidate ◽  
Self Healing ◽  
Intrinsic Shape ◽  
Hard Segments ◽  
Shape Memory Polyurethane

The inherent capability to deform and reform in a predefined environment is a unique property existing in shape memory polyurethane. The intrinsic shape memory ability of the polyurethane is due to the presence of macro domains of soft and hard segments in its bulk, which make this material a potential candidate for several applications. This review is focused on manifesting the applicability of shape memory polyurethane and its composites/blends in various domains, especially to human health such as shielding of electromagnetic interference, medical bandage development, bone tissue engineering, self-healing, implants development, etc. A coherent literature review highlighting the prospects of shape memory polyurethane in versatile applications has been presented.

scholarly journals Self-healing and shape memory functions exhibited by supramolecular liquid-crystalline networks formed by combination of hydrogen bonding interactions and coordination bonding

2021 ◽  
Author(s):  
Junya Uchida ◽  
Masafumi Yoshio ◽  
Takashi Kato
Keyword(s):  
Hydrogen Bonding ◽  
Shape Memory ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
Building Blocks ◽  
Self Healing ◽  
New Approach ◽  
Hydrogen Bonding Interactions ◽  
Coordination Bonding ◽  
Molecular Building Blocks

We here report a new approach to develop self-healing shape memory supramolecular liquid-crystalline (LC) networks through self-assembly of molecular building blocks via combination of hydrogen bonding and coordination bonding. We...

scholarly journals Synthesis and structure/properties characterizations of four polyurethane model hard segments

2018 ◽  
Vol 5 (7) ◽  
pp. 180536 ◽  
Author(s):  
Lei Jiang ◽  
Zhiyong Ren ◽  
Wei Zhao ◽  
Wentao Liu ◽  
Hao Liu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Hard Segment ◽  
Spectral Characteristics ◽  
Hexamethylene Diisocyanate ◽  
H Nmr ◽  
Starting Point ◽  
Hard Segments ◽  
The Relationship ◽  
C Nmr ◽  
Structure Properties

Four model polyurethane (PU) hard segments were synthesized by reaction of butanol with four typical diisocyanates. The four diisocyanates were aromatic 4,4′-diphenylmethane diisocyanate (4,4′-MDI) and MDI-50 (50% mixture of 2,4′-MDI and 4,4′-MDI), cycloaliphatic 4,4′-dicyclohexylmethane diisocyanate (HMDI) and linear aliphatic 1,6-hexamethylene diisocyanate (HDI). FTIR, 1 H NMR, 13 C NMR, MS, X-ray and DSC methods were employed to determine their structures and to analyse their crystallization behaviours and hydrogen bonding interactions. Each of the four PU compounds prepared in the present work displays unique spectral characteristics. The FTIR bands and NMR resonance peaks assigned in the four samples thus provide a reliable database and starting point for investigating the relationship between hard segment structure and the crystallization and hydrogen bonding behaviour in more complex-segmented PU compositions.

Hydrogen-Bonding Interactions in Peptide Nucleic Acid and Deoxyribonucleic Acid:  A Comparative Study

2006 ◽  
Vol 110 (7) ◽  
pp. 3336-3343 ◽  
Author(s):  
Holly Elizabeth Herbert ◽  
Mathew D. Halls ◽  
Hrant P. Hratchian ◽  
Krishnan Raghavachari
Keyword(s):  
Hydrogen Bonding ◽  
Nucleic Acid ◽  
Comparative Study ◽  
Peptide Nucleic Acid ◽  
Deoxyribonucleic Acid ◽  
Hydrogen Bonding Interactions

A Robust, Self-Healable, and Shape Memory Supramolecular Hydrogel by Multiple Hydrogen Bonding Interactions

2018 ◽  
Vol 39 (20) ◽  
pp. 1800138 ◽  
Author(s):  
Zhanbin Feng ◽  
Hongli Zuo ◽  
Weisheng Gao ◽  
Nanying Ning ◽  
Ming Tian ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Shape Memory ◽  
Supramolecular Hydrogel ◽  
Hydrogen Bonding Interactions ◽  
Multiple Hydrogen Bonding
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