Facile synthesis of 1,4-cis-polyisoprene–polypeptide hybrids with different architectures

Abstract

2-Pot synthesis of a number of amino-hydroxy macroinitiators for living NCA ROP allowed to obtain polyisoprene–polypeptide hybrids of different architecture.

New Epoxy Thermosets Derived from a Bisimidazolium Ionic Liquid Monomer: An Experimental and Modeling Investigation

“…At the later stage of cross-linking, when the concentration of remaining amines (primary and secondary) is already low, viscosity and cross-linked medium prevent free diffusion of unreacted components, and side reactions corresponding to the peak at 199 °C (Figure ) become more preferable. Hydroxy groups linked to a tertiary amine by two carbon atoms are known to be stronger nucleophiles than other aliphatic alcohols due to hydrogen bonding with nitrogen atom. , That is why it can be suggested that OH-groups formed at the first stage of reaction may react with remaining epoxy groups (Scheme , OH- ring opening). The previous tertiary amine is also a nucleophile which can also participate in epoxide ring-opening forming an ammonium salt .…”

Unprecedented coupling of natural rubber and ELP: synthesis, characterization and self-assembly properties

“…This reaction was performed as already described. 8 Briefly, 10 g of NR were cut into small pieces and dissolved overnight at RT in 500 mL of THF in round-bottom flask under stirring. In parallel, 550 mg (3.2 mmol) of mCPBA were dissolved in 50 mL of THF, and then added dropwise into the NR solution to epoxidize the PI.…”

“…This reaction was performed under argon atmosphere as already described. 8 Briefly, 6 g of purified PIEG 5500 g mol −1 (equivalent to 1.2 mmol of aldehyde groups) were dissolved in 25 mL of dry THF. Then, 1.02 g (4.8 mmol, 4 eq.)…”

“…The polyisoprene originally found in natural rubber (NR) is of high molar mass (>500 kg mol −1 ), and to reduce it a partial epoxidation of NR by m-CPBA followed by cleavage with periodic acid of the formed epoxy units was carried out. 8,21 The final purified product heterotelechelic keto/aldehyde PI (PIEG) was characterized by 1 H NMR and size exclusion chromatography (SEC) (Fig. S1 and S2 †).…”

“…Polypeptide-block-PI copolymers can be obtained by ring opening polymerization of the N-carboxyanhydride of the selected amino acid using the PI as a macroinitiator. This approach was successfully used to synthesize poly(γ-benzylglutamate), 7,8 poly(L-lysine), 9 and poly(ε-tert-butyloxycarbonyl-L-lysine 8 onto polyisoprene. However, a limitation of this approach is that the polypeptide blocks were always based on a single amino acid, which is obviously not representative of the complex protein structures.…”