Synthesis and characterization of high grafting density bottle-brush poly(oxa)norbornene-g-poly(ε-caprolactone)

Abstract

The synthesis and the ring-opening metathesis polymerization of well-defined poly(ε-caprolactone)-based (oxa)norbornene macromonomers bearing two poly(ε-caprolactone) chains on the polymerizable entity are reported.

Polynorbornene‐g‐poly(ethylene oxide) Through the Combination of ROMP and Nitroxide Radical Coupling Reactions

“…PNB 100 ‐ g ‐PEO 45(through) had a 49% crystallinity (Table , Run 5), which is in accordance with values reported in the literature for bottlebrush PNB‐ g ‐PEO . The substantial reduction of crystallinity of the PEO grafts in PNB 100 ‐ g ‐PEO 45(through) compared to the commercially available PEO (Table , Run 1) and to PNB 100 ‐ g ‐PEO 45(onto) (Table , Run 4) is attributed to the brush structure of the copolymer, where the PEO grafts adopt a stretched, less flexible rod‐like conformation . Nevertheless, it is worth mentioning that the 43% crystallinity of the PEO macromonomer M1 cannot be attributed to a restriction of conformational freedom, but seems to be the result of the reaction conditions.…”

“…Graft copolymer PNB 100 ‐ g ‐PEO 45(onto) showed an increase in thermal stability compared to the polynorbornene backbone P1 with a 5% weight loss decomposition of 293°C instead of 220°C (Table , Run 5 vs. Run 4). Such a behavior could be attributed to the strong intramolecular van der Waals interactions among the PEO side chains of the bottlebrush polymer …”

High Molar Mass Poly(1,4-butadiene)-graft-poly(ε-caprolactone) Copolymers by ROMP: Synthesis via the Grafting-From Route and Self-Assembling Properties

“…25 The characteristics thermal temperatures of PBu-g-PCL graft copolymers are similar to those of PNB-g-PCL graft copolymers reported in the literature. [16][17][18]26,27 The crystallinities of the linear PCL-based MMs (Table 3, runs 3 and 4) and PBu-g-PCL graft copolymers (Table 3, runs 5−8) were calculated by comparison with the reported enthalpy of fusion for the parent polymer crystal (ΔH f 100% crystalline PCL = 140 J g −1 ). 28 The results show a significant decrease of the enthalpy of fusion of the PBu 198 -g-PCL 48 compared to the linear PCL 38 homopolymer (91 J g −1 for PCL 38 and 64 J g −1 for PBu 198 -g-PCL 48 ), resulting in a lower crystallinity.…”

“…This low mobility and capability for crystallization can be explained by the specific architecture of graft copolymers, resulting in a restriction of conformational freedom, compared to free chains of PCL. 27 Morphology of Diluted PBu 198 -g-PCL 48 Particles. Small-angle X-ray scattering (SAXS) intensity curves were collected from PBu 198 -g-PCL 48 batch at a concentration of 10 g L −1 in toluene.…”

Cationic Bottlebrush Polymers from Quaternary Ammonium Macromonomers by Grafting‐Through Ring‐Opening Metathesis Polymerization

“…Different polymerizable terminal norbornene or anchor groups of MMs influence the ROMP propagation rate due to steric and electronic effects 39–41. For example, heteroatoms present in (oxa)norbornene anchor group can partially interfere with the Grubbs catalyst to slow the ROMP propagation rate 42. Modification of the anchor group to a exo‐norbornene structure can significantly increase the ROMP rate of MMs, while yielding a narrow molecular weight distribution 40…”