Preparation of aqueous crosslinked dispersions of functionalized poly(d,l-lactic acid) with a thermomechanical method

Rämö, Virpi; Anghelescu-Hakala, Adina; Nurmi, Leena; Mehtiö, Tuomas; Salomäki, Elina; Härkönen, Mika; Harlin, Ali

doi:10.1016/j.eurpolymj.2012.06.005

Cited by 12 publications

(17 citation statements)

References 14 publications

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“…Depending on the composition, the glass transition is shifted to a higher temperature compared to T g of PEG or PCL. This shift results from the contributions of the urethane hard segments and also from restrictions imposed by the crosslinked structure, which reduce the free volume of the amorphous phase and chain flexibility . Also, the presence of a unique glass transition [see the zoomed‐in‐view of the glass transition region, Figure (c)] suggests the miscibility of PEG and PCL in the amorphous phase.…”

Section: Resultsmentioning

confidence: 99%

Thermo‐responsive polyurethane hydrogels based on poly(ethylene glycol) and poly(caprolactone): Physico‐chemical and mechanical properties

Fonseca

Trinca

Felisberti

2016

J of Applied Polymer Sci

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In this work, we present the synthesis and characterization of chemically crosslinked polyurethanes (PU) composed of poly(ethylene glycol) (PEG) and poly(caprolactone) diol (PCL-diol), as hydrophilic and hydrophobic segments respectively, poly(caprolactone) triol (PCL-triol), to induce hydrolysable crosslinks, and hexamethylene diisocyanate (HDI). The syntheses were performed at 45 8C, resulting in polyurethanes with different PEG/PCL-diol/PCL-triol mass fractions. All the PUs are able to crystallize and their thermal properties depend on the global composition. The water uptake capacities of the PU increase as the PEG amount increases. The water into hydrogels is present in different environments, as bounded, bulk and free water. The PU hydrogels are thermoresponsive, presenting a negative dependence of the water uptake with the temperature for PEG rich networks, which gradually changes to a positive behavior as the amount of poly(caprolactone) (PCL) segments increases. However, the water uptake capacity changes continuously without an abrupt transition. Scanning electron microscopy (SEM) analyses of the hydrogel morphology after lyophilization revealed a porous structure. Mechanical compression tests revealed that the hydrogels present good resilience and low recovery hysteresis when they are subject to cycles of compression-decompression. In addition, the mechanical properties of the hydrogels varies with the composition and crosslinking density, and therefore with the water uptake capacity. The PU properties can be tuned to fit for different applications, such as biomedical applications.

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Section: Resultsmentioning

confidence: 99%

Thermo‐responsive polyurethane hydrogels based on poly(ethylene glycol) and poly(caprolactone): Physico‐chemical and mechanical properties

Fonseca

Trinca

Felisberti

2016

J of Applied Polymer Sci

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“…However, up until now, itaconate has not been well studied for polyester synthesis, neither by conventional catalysts nor by biocatalysts. Limited kinds of itaconate-based polyesters were synthesized using conventional chemical catalysts [8,9,10,43,44,45,46,47,48]. Only two papers referred to the enzymatic polymerizations of itaconate with other monomers: Barrett et al .…”

Section: Introductionmentioning

confidence: 99%

Enzyme-Catalyzed Synthesis of Unsaturated Aliphatic Polyesters Based on Green Monomers from Renewable Resources

et al. 2013

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Bio-based commercially available succinate, itaconate and 1,4-butanediol are enzymatically co-polymerized in solution via a two-stage method, using Candida antarctica Lipase B (CALB, in immobilized form as Novozyme® 435) as the biocatalyst. The chemical structures of the obtained products, poly(butylene succinate) (PBS) and poly(butylene succinate-co-itaconate) (PBSI), are confirmed by 1H- and 13C-NMR. The effects of the reaction conditions on the CALB-catalyzed synthesis of PBSI are fully investigated, and the optimal polymerization conditions are obtained. With the established method, PBSI with tunable compositions and satisfying reaction yields is produced. The 1H-NMR results confirm that carbon-carbon double bonds are well preserved in PBSI. The differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) results indicate that the amount of itaconate in the co-polyesters has no obvious effects on the glass-transition temperature and the thermal stability of PBS and PBSI, but has significant effects on the melting temperature.

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“…These requirements are often difficult to fulfill with solvent‐intensive dispersion preparation methods. Therefore, thermomechanical dispersion preparation methods that do not require organic solvents have been developed . Under mild conditions, temperatures below 100 °C and ambient pressure, dispersions can be prepared from low‐molecular‐weight PLA‐based polymers .…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, thermomechanical dispersion preparation methods that do not require organic solvents have been developed . Under mild conditions, temperatures below 100 °C and ambient pressure, dispersions can be prepared from low‐molecular‐weight PLA‐based polymers . With higher molecular weights (weight‐average molecular weight = 16,000 g/mol), dispersion preparation is more tedious because of the high melt viscosity of the polymer .…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, low‐molecular‐weight PLA lacks the mechanical properties required to form and maintain a uniform coating layer in barrier applications. These obstacles can be overcome by the crosslinking of low‐molecular‐weight PLA after dispersion preparation . With crosslinking reactions, an enhanced performance of the polymer can be achieved; this can create new applications for low‐molecular‐weight PLA and, thus, increase its value chain.…”

Section: Introductionmentioning

confidence: 99%

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Crosslinkable poly(lactic acid)‐based materials: Biomass‐derived solution for barrier coatings

Mehtiö

Anghelescu-Hakala

Hartman

et al. 2016

J of Applied Polymer Sci

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The demand for biobased barrier packaging alternatives is constantly growing. Poly(lactic acid) (PLA)-based polymers are one of the most extensively studied biomass-derived synthetic polymers; however, they typically lack water-barrier properties. We synthesized a copolymer of D,L-lactic acid, 1,4-butanediol, and itaconic acid [poly(D,L-lactic acid-1,4-butanediol-itaconic acid) (PLAB-DIA)] via bulk polycondensation. The radical crosslinking reactions of the synthesized polymer were investigated with bulk crosslinking trials to find a formulation that was suitable for a rapidly crosslinkable barrier coating. The crosslinking efficiency was tested with methacrylate and acrylate crosslinkers together with peroxide radical initiators. Poly(ethylene glycol) diacrylate (numberaverage molecular weight 5 250 g/mol) together with dilauroyl peroxide proved to be the best crosslinker-initiator combination. An aqueous dispersion of PLABDIA was prepared with a thermomechanical method and applied to commercial boxboard on a pilotscale line coater. With a coating weight of 10 g/m 2 , a water vapor transmission rate of 22.8 g/m 2 d was achieved, and this coating outperformed commercial extruded PLA coatings. The samples also showed very good grease resistance and would, therefore, be a good solution for the packaging of dry and fatty goods.

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Preparation of aqueous crosslinked dispersions of functionalized poly(d,l-lactic acid) with a thermomechanical method

Cited by 12 publications

References 14 publications

Thermo‐responsive polyurethane hydrogels based on poly(ethylene glycol) and poly(caprolactone): Physico‐chemical and mechanical properties

Thermo‐responsive polyurethane hydrogels based on poly(ethylene glycol) and poly(caprolactone): Physico‐chemical and mechanical properties

Enzyme-Catalyzed Synthesis of Unsaturated Aliphatic Polyesters Based on Green Monomers from Renewable Resources

Crosslinkable poly(lactic acid)‐based materials: Biomass‐derived solution for barrier coatings

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