Rewritable Shape-Memory Polylactic Acid Fabricated by Thermo-Reversible Cross-Linking Based on the Diels-Alder Reaction

new thermoset has been prepared from a bismaleimidic terminated polycaprolactone polyester and a tris-furan compound acting as a crosslinker via the Diels-Alder reaction between the furan and maleimide functionalities. Owing to the reversibility of the Diels-Alder chemistry and the increased mobility of the crosslinked polyester chains, this material had the ability to mend scratches under mild temperature conditions. The synthesized precursors and resulting crosslinked material were characterized using 1H NMR, FT-IR, GPC, TGA and DSC methods. The scratch mendability of the material was investigated using optical microscopy.

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3D printed remendable polylactic acid blends with uniform mechanical strength enabled by a dynamic Diels–Alder reaction

Polymer Chemistry ◽

10.1039/c7py00310b ◽

2017 ◽

Vol 8 (13) ◽

pp. 2087-2092 ◽

Cited By ~ 30

Author(s):

Gayan A. Appuhamillage ◽

John C. Reagan ◽

Sina Khorsandi ◽

Joshua R. Davidson ◽

Walter Voit ◽

...

Keyword(s):

Mechanical Properties ◽

Mechanical Strength ◽

Polymer Blends ◽

Polylactic Acid ◽

Alder Reaction ◽

Diels Alder ◽

Diels Alder Reaction ◽

3D Printed

We demonstrate that uniform mechanical properties can be achieved in 3D printed polymer blends by using a dynamic Diels–Alder reaction.

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Towards Thermally Reversible Networks Based on Furan-Functionalization of Jatropha Oil

Molecules ◽

10.3390/molecules25163641 ◽

2020 ◽

Vol 25 (16) ◽

pp. 3641

Author(s):

Frita Yuliati ◽

Peter J. Deuss ◽

Hero J. Heeres ◽

Francesco Picchioni

Keyword(s):

Ring Opening ◽

Alder Reaction ◽

Diels Alder ◽

Epoxide Ring ◽

Cross Linking ◽

Jatropha Oil ◽

Optimum Conditions ◽

Epoxide Ring Opening ◽

Diels Alder Reaction ◽

Ring Opening Reaction

A novel biobased monomer for the preparation of thermally reversible networks based on the Diels-Alder reaction was synthesized from jatropha oil. The oil was epoxidized and subsequently reacted with furfurylamine to attach furan groups via an epoxide ring opening reaction. However, furfurylamine also reacted with the ester groups of the triglycerides via aminolysis, thus resulting in short-chain molecules that ultimately yielded brittle thermally reversible polymers upon cross-linking via a Diels-Alder reaction. A full-factorial experimental design was used in finding the optimum conditions to minimize ester aminolysis and to maximize the epoxide ring opening reaction as well as the number of furans attached to the modified oil. The optimum conditions were determined experimentally and were found to be 80 °C, 24 h, 1:1 molar ratio, with 50 mol % of LiBr with respect to the modified oil, resulting in 35% of ester conversion, 99% of epoxide conversion, and an average of 1.32 furans/triglyceride. Ultimately, further optimization by a statistical approach led to an average of 2.19 furans per triglyceride, which eventually yielded a flexible network upon cross-linking via a Diels-Alder reaction instead of the brittle one obtained when the furan-functionalization reaction was not optimized.

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New insights into the cross-linking and degradation mechanism of Diels–Alder hydrogels

Journal of Materials Chemistry B ◽

10.1039/c4tb01680g ◽

2015 ◽

Vol 3 (3) ◽

pp. 449-457 ◽

Cited By ~ 30

Author(s):

Susanne Kirchhof ◽

Andrea Strasser ◽

Hans-Joachim Wittmann ◽

Viktoria Messmann ◽

Nadine Hammer ◽

...

Keyword(s):

Ring Opening ◽

Degradation Mechanism ◽

Alder Reaction ◽

Diels Alder ◽

Cross Linking ◽

Diels Alder Reaction ◽

Maleamic Acid ◽

The Cross ◽

Hydrolysis Of

Degradation of Diels–Alder hydrogels occurs by retro-Diels–Alder reaction followed by OH−-catalyzed ring-opening hydrolysis of maleimide groups to unreactive maleamic acid derivatives.

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