Synthesis, kinetics of photo-dimerization/photo-cleavage and physical properties of coumarin-containing branched polyurethanes based on polycaprolactones

Rivero, R. Seoane; Solaguren, Pilar Bilbao; Zubieta, Koldo Gondra; Peponi, Laura; Marcos‐Fernández, Ángel

doi:10.3144/expresspolymlett.2016.10

Cited by 24 publications

(22 citation statements)

References 25 publications

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“…Numerous studies are available on polycaprolactone based polyurethanes and on their applications, in the medical field . However most of them only apply indirect methods at best in order to characterize structure, while only a handful attempt to use more direct imaging techniques such as AFM . At this point we have to emphasize the fact that achieving a polyurethane material with desirable properties that meets the extremely demanding requirements of medical applications is not at all trivial.…”

Section: Introductionmentioning

confidence: 99%

Mechanical mapping and morphology across the length scales unveil structure-property relationships in polycaprolactone based polyurethanes

Gojżewski

Imre

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et al. 2016

J. Polym. Sci. Part B: Polym. Phys.

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Segmented polyurethane elastomers for biomedical applications were synthesized and studied at macroscopic (by mechanical testing) and meso/nanoscopic length scales (by atomic force microscopy, AFM). The polyurethanes are composed of 4,4'‐methylenebis(phenyl isocyanate), 1,4‐butanediol and an ε‐polycaprolactone diol. The stoichiometric ratio of the isocyanate and hydroxyl groups is constant, but the polymer diol to total diol—varies from 0 to 100 %. We show the representative features of the morphology from phase separation to mixed phases, how this is related to the mechanical properties in the bulk and locally, at exposed free surfaces and at the nanoscale. We propose a morphological model considering the molecular structure, the length of hard segments, and the dimensions of both the soft and the hard phases, respectively. Understanding such structure–property relations is pivotal to establishing designer materials and controlling the performance of the final product to achieve optimal properties in polyurethane based medical devices. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2298–2310.

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Section: Introductionmentioning

confidence: 99%

Mechanical mapping and morphology across the length scales unveil structure-property relationships in polycaprolactone based polyurethanes

Gojżewski

Imre

Check

et al. 2016

J. Polym. Sci. Part B: Polym. Phys.

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“…They have been employed as hard segments in polyethylene glycol (PEG)‐based PUs, and also in PCL‐based PUs . Although coumarins have all the previously mentioned advantages, it has been shown that when introducing monohydroxyl‐coumarin derivatives into polyurethane networks as chain‐end crosslinkable groups, low photo‐conversion degrees are observed since the coumarin moieties have a low probability of reaching each other to photo‐dimerize . Thus, the use of dihydroxyl‐coumarin based species offers the opportunity to synthesize PUs in which the coumarin moieties are within the polymeric chains, which will give the final material a higher responsiveness to light .…”

Section: Introductionmentioning

confidence: 99%

Influence of Poly(ε‐caprolactone) Molecular Weight and Coumarin Amount on Photo‐Responsive Polyurethane Properties

Salgado

Arrieta

Peponi

et al. 2016

Macro Materials & Eng

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Photo‐reversible polyurethane (PU) coatings based on coumarin diol (CD) are obtained. Initially, pre‐polymers based on different amounts of coumarin (5, 15, and 25 mol%) and 1,6‐hexamethylene diisocyanate are prepared to obtain PUs with a large incorporation of CD and high molecular weight. The pre‐polymer is posterior reacted with poly(ε‐caprolactone) diol (PCL‐diol), either with molecular weight trueM¯n = 530 or 2000 g mol–1. The thermal stabilities of the PUs are studied using thermogravimetric analysis. Polymers with a higher content of CD present higher stability. The thermal transitions and the mechanical response are analyzed using differential scanning calorimetry and strain‐stress tests, respectively. Moreover, the photo‐reversibility of CD‐based PUs is followed by UV absorption. In general, photo‐dimerization induces better mechanical properties of the final PUs. Materials obtained with short PCL‐diol (trueM¯n = 530 g mol–1) and the highest amount of CD present higher reversibility processes. Therefore, these polymers are promising for application as coating systems.

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“…The authors of this review came back to 7-(hydroxyethoxy)-4-methyl coumarin as a monomer for preparing photoreactive polyurethanes. This mono-hydroxylated coumarin (5 wt.% and 10 wt.%) was reacted with polycaprolactone (PCL) diol, triol or tetrol to synthesise coumarin end-capped linear and branched polyurethane [107]. However, in this case the polymer structure was controlled to avoid gelation processes that were reported previously in similar structures [108,109].…”

Section: Enhancement Mechanical Properties By Irradiationmentioning

confidence: 99%

“…Stress-strain curves for coumarin-functionalised polyurethane: Non-irradiated, irradiated at 354 nm, irradiated at 354 nm and 254 nm, and irradiated again at 354 nm. Reprinted with permission from[107] (©2016, MDPI).…”

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confidence: 99%

Coumarins into Polyurethanes for Smart and Functional Materials

et al. 2020

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Polyurethanes are of undoubted interest for the scientific community and the industry. Their outstanding versatility from tailor-made structures turns them into major polymers for use in a wide range of different applications. As with other polymers, new, emerging molecules and monomers with specific attributes can provide new functions and capabilities to polyurethanes. Natural and synthetic coumarin and its derivatives are characterised by interesting biological, photophysical and photochemical properties. Then, the polyurethanes can exploit those features of many coumarins which are present in their composition to achieve new functions and performances. This article reviews the developments in the proper use of the special properties of coumarins in polyurethanes to produce functional and smart materials that can be suitable for new specific applications.

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Synthesis, kinetics of photo-dimerization/photo-cleavage and physical properties of coumarin-containing branched polyurethanes based on polycaprolactones

Cited by 24 publications

References 25 publications

Mechanical mapping and morphology across the length scales unveil structure-property relationships in polycaprolactone based polyurethanes

Mechanical mapping and morphology across the length scales unveil structure-property relationships in polycaprolactone based polyurethanes

Influence of Poly(ε‐caprolactone) Molecular Weight and Coumarin Amount on Photo‐Responsive Polyurethane Properties

Coumarins into Polyurethanes for Smart and Functional Materials

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