Theoretical predictions on microphase separation in polyurethane: Combinatorial design, synthesis and demonstration of shape memory property

Erekkath, Swathi; Sreejalekshmi, K G

doi:10.1016/j.mtcomm.2018.04.007

Cited by 12 publications

(9 citation statements)

References 44 publications

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“…This phenomenon can be explained by the competition of hydrogen bonding formed between -NH groups in urethane linkages with either urethane carbonyl or oxygen functional group present in SSs. Basically, the phase separation occurs when the HSs assemble themselves via hydrogen bonding, and thus the hard domains are formed and excluded from the matrix of soft phase [47,48]. However, in the case that the SSs possess functional groups acting as acceptors which is strong enough to interact with -NH group in HSs, phase mixing is supposed to occur [40].…”

Section: Microphase Separation Behavior 321 the Effect Of Long Chamentioning

confidence: 99%

Palm kernel oil polyol based shape memory polyurethane: effect of polycaprolactone and polyethylene glycol as soft segment

Trinh

Jaafar

Viet

et al. 2020

Mater. Res. Express

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Shape memory polyurethane (SMPU) with its outstanding characteristics is categorized as smart materials and has been utilized in a wide range of applications. In this study, a series of palm kernel oil polyol (PKOp) -based SMPU with the combination of polycaprolactone (PCL) and polyethylene glycol (PEG) as soft segment was synthesized and characterized for the first time. The synthesized SMPUs were examined via several techniques such as Fourier transform infrared, x-ray diffraction, thermal analysis, tensile and shape memory test. The combination of PCL and PEG in PKOp-based SMPU has overcome the drawbacks of PKOp-based PU with only PCL or PEG as soft segment. PU-PCL4PEG4 exhibited tensile strength, Young's modulus, and shape fixity of 5.7 MPa, 53.9 MPa, and 97%, respectively. For the variation of PEG molar ratio, PU-0.6PEG demonstrated good modulus (151.3 MPa) and shape fixity (99%) but its tensile strength and tensile strain at break were compromised as compared to other samples.

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Section: Microphase Separation Behavior 321 the Effect Of Long Chamentioning

confidence: 99%

Palm kernel oil polyol based shape memory polyurethane: effect of polycaprolactone and polyethylene glycol as soft segment

Trinh

Jaafar

Viet

et al. 2020

Mater. Res. Express

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show abstract

“…The microphase separation is achieved via the basic chemistries that are used to synthesise polyurethane. [3][4][5] The impact of microphase separation and hydrogen bonding of polyurethane is greater on crystallisation, and final mechanical properties. [6][7][8] The following factors: development of crystallinity in the hard segments, the distinction in melting points, the contrast in the segmental polarity, segmental length, final composition and molecular weight are the driving forces for the microphase segregation.…”

Section: Introductionmentioning

confidence: 99%

The effect of OMMT reinforcement and annealing treatment on mechanical and thermal properties of Polyurethane Copolymer nanocomposites

Albozahid

Naji

Alobad

et al. 2021

Journal of Elastomers & Plastics

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This study focuses on a new fabrication of nanocomposite based on Polyurethane Copolymer (PUC) intercalated with organo-modified montmorillonite nanoparticles (OMMT), via an efficient combination of solution mixing and melt blending processes. The combination of solution mixing and melt interaction processes produced PUC/OMMT nanocomposites with enhanced properties. The OMMT filled PUC was characterised by TEM and tensile test. The effect of thermal treatment process was also studied due to subsequent microphase separation of PUC resulting from microdomain miscibility. TEM observation recognised a decent dispersion state of OMMT within PUC, owing to their exfoliated and intercalated structure. This morphology was greatly influenced by induced thermal treatment. The dynamic mechanical thermal analysis (DMTA) revealed that storage modulus and glass transition temperature of the nanocomposites increased with OMMT incorporation. The tensile modulus and tensile strength of nanocomposites showed an improvement with the addition of OMMT.

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“…It is obvious that the molecular structure (e.g., molecular mass and geometric structure) of the single precursor components plays an important role. However, of similar importance are interactions between the individual molecules based on secondary forces (e.g., hydrogen bonds), which could influence for example the crystallinity, the phase separation, and the interphase connections of the segments, and thus, predefine the morphological structure, which greatly influences the addition reaction (Erekkath and Sreejalekshmi, 2018). For the formation of polyurethane foams, in addition to the urethane formation, a so-called blowing reaction is induced by the addition of water, which aims to generate a gas that foams the reactive mixture (most commonly CO 2 ).…”

Section: Introductionmentioning

confidence: 99%

Reactivity of Isocyanate-Functionalized Lignins: A Key Factor for the Preparation of Lignin-Based Polyurethanes

et al. 2019

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Using isocyanate-functionalized Kraft lignin as a reactive macromonomer for the preparation of polyurethane foams by a prepolymer technique is a well-known strategy to incorporate the biomacromolecule into a higher value polymer material. However, as of today the mechanical properties of the resulting materials are still insufficient for a number of possible applications. One reason for this limitation is that the reaction pathway and the morphological arrangement of such foams is of uttermost complexity and depends on a large number of influencing material-intrinsic factors. One important parameter is the reactivity of the functionalized lignin, which has a great impact on the interphase reaction kinetics and thus, on the geometry and mechanical properties of the resulting polyurethane foams. The reactivity is implied, amongst others, by the electron affinity of the isocyanate moiety. Herein, we investigate the reactivity of Kraft lignin modified with different commercially used isocyanates in the reaction with conventional polyols. Therefore, differently reactive prepolymers were synthesized, characterized and polyurethane foams were prepared thereof by using these compounds and the foam formation kinetics, morphological as well as mechanical properties were investigated. Finally, the results were supported by quantum mechanical calculations of the electron affinities of representative model compounds for the lignin-based prepolymers. This work gives rise to a better understanding of the effect of the reactivity and isocyanate structure linked to Kraft lignin on the polyurethane formation and enables rational choice of the isocyanate for pre-functionalization of lignin to prepare materials with better mechanical performance.

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Theoretical predictions on microphase separation in polyurethane: Combinatorial design, synthesis and demonstration of shape memory property

Cited by 12 publications

References 44 publications

Palm kernel oil polyol based shape memory polyurethane: effect of polycaprolactone and polyethylene glycol as soft segment

Palm kernel oil polyol based shape memory polyurethane: effect of polycaprolactone and polyethylene glycol as soft segment

The effect of OMMT reinforcement and annealing treatment on mechanical and thermal properties of Polyurethane Copolymer nanocomposites

Reactivity of Isocyanate-Functionalized Lignins: A Key Factor for the Preparation of Lignin-Based Polyurethanes

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