77871-55-7Relevant academic research and scientific papers
Vinylogous urethane vitrimers
Denissen, Wim,Winne, Johan M.,Du Prez, Filip E.,Rivero, Guadalupe,Nicola, Renaud,Leibler, Ludwik
, p. 2451 - 2457 (2015)
Vitrimers are a new class of polymeric materials with very attractive properties, since they can be reworked to any shape while being at the same time permanently cross-linked. As an alternative to the use of transesterification chemistry, we explore catalyst-free transamination of vinylogous urethanes as an exchange reaction for vitrimers. First, a kinetic study on model compounds reveals the occurrence of transamination of vinylogous urethanes in a good temperature window without side reactions. Next, poly(vinylogous urethane) networks with a storage modulus of ≈2.4 GPa and a glass transition temperature above 80 °C are prepared by bulk polymerization of cyclohexane dimethanol bisacetoacetate, m-xylylene diamine, and tris(2-aminoethyl)amine. The vitrimer nature of these networks is examined by solubility, stress-relaxation, and creep experiments. Relaxation times as short as 85 s at 170 °C are observed without making use of any catalyst. In addition, the networks are recyclable up to four times by consecutive grinding/compression molding cycles without significant mechanical or chemical degradation. Catalyst-free vitrimers based on the transamination of vinylogous urethanes are prepared from readily accessible chemicals. These high Tg, cross-linked materials exhibit excellent mechanical properties, while the exchangeable bonds enable full stress-relaxation on short time scales and recycling over many cycles.
COMPOSITIONS COMPRISING A POLYMERIC NETWORK
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Paragraph 0532, (2017/12/15)
The present invention relates to a composition comprising a polymeric network having at least one unit of formula (I), (II), and/or (III); (I) (II) (III) wherein said composition is obtained by contacting at least one compound A comprising at least two functions selected from the group of function of formula X—C(═O)—CHR1—C(═O)—R2, —C(═O)—C—R2; or —C(═O)—CR1═CR2—NR4R5; wherein at least 25% by weight of compounds A have a functionality ≦5, with % by weight relative to the total weight of compounds A; with at least one compound B comprising at least one NH2, or NH3+ groups; wherein X, R1, R2, R3, R4, R5, L1 and L2 have the same meaning as that defined in the claims. The present invention also relates to a compound comprising at least two units and at most 5 units of formula (I), (II), and/or (III); wherein R1, R2, R3, X, L1 and L2 have the same meaning as that defined in the claims. The present invention also relates to processes for preparing said composition and said compounds, to material, articles, and polymers comprising or using said compositions and compounds, and the use thereof.
