Thermal Degradation Effects on Polyurethanes and Their Nanocomposites

Navarro-Baena, Iván; Arrieta, Marina P.; Mujica-Garcia, Alicia; Sessini, Valentina; López, Daniel; Kenny, J. M.; Peponi, Laura

doi:10.1002/9781119117711.ch7

Cited by 5 publications

(1 citation statement)

References 138 publications

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“…No significant differences were observed by FTIR analysis (not shown) probably due to the low amount of nHA used in the present study. It is well known that the first degradation step of PU corresponds to the degradation of urethane groups [38,39]. Regarding Fig.…”

Section: Resultsmentioning

confidence: 96%

Biodegradable nanocomposites based on poly(ester-urethane) and nanosized hydroxyapatite: Plastificant and reinforcement effects

Navarro-Baena

Arrieta

Sonseca

et al. 2015

Polymer Degradation and Stability

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The processing and characterization of biodegradable nanocomposites based on poly(ester-urethane)s reinforced with different amounts (0.5, 1 and 3 wt %) of nanosized hydroxyapatite (nHA) are reported. The selected poly(ester-urethane) was synthesized starting from a tri-block copolymer based on poly(ε-caprolactone) (PCL) and poly(L-lactic acid) (PLLA). The nanocomposites were prepared by extrusion and by press molding. Several techniques were applied to investigate the properties of the nanocomposites. Electron microscopy revealed that the poly(ester-urethane) matrix is able to phase separate and that the addition of well-dispersed nanofillers modifies the dimension of the segregated phase. The thermal stability of the PU matrix, regulated by the PLLA block, decreased when low contents of nHA (0.5 and 1 wt %) were added, even if the thermal stability of the PCL-block was increased for each nHA amount. The good mechanical response of the nanocomposites confirmed the absence of agglomerates in the dispersion of the nanofillers in the polymeric matrix. The nHA presence also increased the surface hydrophilicity. Furthermore, rheology measurements, mechanical and thermal tests demonstrated the different behavior induced by the addition of nHA in different amounts. In fact, nHA acts as plasticizer at low concentrations (0.5, 1 wt %) and as reinforcement at a higher nHA amount (3 wt %). In vitro degradation tests were performed using a phosphate buffer solution. The results reported here are relevant for the development of nanocomposites based on a biodegradable and biocompatible polymeric matrix reinforced with small amounts of biocompatible nanofillers for different applications, especially in the biomedical field.Keywords: mechanical properties; phase morphology; nanocomposite; poly(lactide); biodegradable; poly(ester-urethane) Abbreviations DMA: Dynamic-mechanical analysis; DSC: Differential scanning calorimetry; FE-SEM: Field emission electron microscopy; HA: Hydroxyapatite; HDI: hexamethylene diisocyanate; nHA: Nanosized hydroxyapatite; PU: poly(ester-urethane); PU+0.5 HA: Nanocomposite of poly(ester-urethane) with 0.5 wt % of HA; PU+1 HA: Nanocomposite of poly(ester-urethane) with 1 wt % of HA; PU+3 HA: Nanocomposite of poly(ester-urethane) with 3 wt % of HA; PCL: Poly(ε-caprolactone); PLLA: Poly(Llactic acid); TEM: Transmission electron microscopy; Tg: Glass transition temperature; 3 TGA: Thermogravimetric analysis; Tm: melting temperature; WCA: water contact angle.

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Section: Resultsmentioning

confidence: 96%

Biodegradable nanocomposites based on poly(ester-urethane) and nanosized hydroxyapatite: Plastificant and reinforcement effects

Navarro-Baena

Arrieta

Sonseca

et al. 2015

Polymer Degradation and Stability

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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 Effect of High Molecular Weight Bio-based Diamine Derivative of Dimerized Fatty Acids Obtained from Vegetable Oils on the Structure, Morphology and Selected Properties of Poly(ether-urethane-urea)s

2017

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Thermal Degradation Effects on Polyurethanes and Their Nanocomposites

Cited by 5 publications

References 138 publications

Biodegradable nanocomposites based on poly(ester-urethane) and nanosized hydroxyapatite: Plastificant and reinforcement effects

Biodegradable nanocomposites based on poly(ester-urethane) and nanosized hydroxyapatite: Plastificant and reinforcement effects

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

The Effect of High Molecular Weight Bio-based Diamine Derivative of Dimerized Fatty Acids Obtained from Vegetable Oils on the Structure, Morphology and Selected Properties of Poly(ether-urethane-urea)s

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