Anionic polymerization of biomass‐derived furfuryl methacrylate: Controlling polymer tacticity and thermoreversibility

Abstract

Biomass‐derived furfuryl methacrylate (FMA) has been successfully polymerized for the first time by anionic polymerization to produce atactic (at‐), isotactic (it‐), or syndiotactic (st‐) poly(furfuryl methacrylate) (PFMA), depending on initiator structure and reaction conditions. Thermal properties of the PFMA materials are strongly affected by the polymer tacticity. Most notably, while both isotactic and syndiotactic polymers can undergo inter‐ or intrachain crosslinking reactions when heated to 290 °C, there is no evidence for the atactic polymer to perform the same reaction. Furthermore, the PFMA tacticity also greatly affects the amount of stable carbonaceous materials it produces when heated to 650 °C, with st‐PFMA forming the largest amount of such materials (26.9%), as compared to only 5.6% by at‐PFMA. Using the Diels–Alder (DA) “click reaction” between the reactive furfuryl group within the PFMA polymers as the diene equivalent and a bismaleimide as the dienophile, thermoreversible smart polymers have been successfully prepared. Thermoreversibility of the preformed crosslinked polymers has been demonstrated, thanks to the facile retro‐DA reaction upon heating and the DA reaction upon cooling of such self‐healing materials. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2793–2803

Organocatalytic Polymerization of Furfuryl Methacrylate and Post‐Diels–Alder Click Reaction to Cross‐Linked Materials

“…It is noted here that the endothermic peak observed on the DSC curve, here taken as T g , is in the similar temperature range to that of the retro‐DA reaction of PFMA‐BM materials. [4c], Hence, they could be overlapping with each other in the current case (i.e., softening of the chain facilitates the retro‐DA, vice versa), although the characteristic of the thermal transition resembles more like T g , as also shown by DMA curves (vide infra).…”

“…To investigate the crosslinking behavior of PFMA with C 60 , we employed the pristine PFMA prepared by KH in THF, due to its relative low molecular weight ( M n = 8.48 kg mol −1 ) and narrow molecular weight distribution ( Đ = 1.40) as well as its near perfect atactic microstructure ( mr = 53.0%). After varying the reaction conditions, it was found that the reaction attaches C 60 to PFMA took place only under visible light irradiation but not in dark.…”

“…[4f], Singha and co‐workers employed the atom‐transfer radical polymerization of FMA or copolymerization of FMA with MMA to produce gel‐free polymers with controlled molecular weights. [4c,d], Interestingly, anionic polymerization of FMA, either by the classical anionic polymerization method using common organolithium initiators or by the group‐transfer polymerization method, was not successful, presumably due to the reactive furfuryl group in FMA . Nevertheless, we recently reported the first successful anionic polymerization of FMA, achieving the synthesis of atactic at ‐PFMA ( mr = 48%) by KH at ambient temperature in toluene or THF, highly isotactic it ‐PFMA ( mm = 97%) by lithium ester enolate LiOC(O i Pr) = CMe 2 at −78 °C in toluene, and moderately syndiotactic st ‐PFMA ( rr = 70%) by LiOC(O i Pr) = CMe 2 in the presence of an aluminum Lewis acid at −78 °C in THF .…”

“…[4c,d], Interestingly, anionic polymerization of FMA, either by the classical anionic polymerization method using common organolithium initiators or by the group‐transfer polymerization method, was not successful, presumably due to the reactive furfuryl group in FMA . Nevertheless, we recently reported the first successful anionic polymerization of FMA, achieving the synthesis of atactic at ‐PFMA ( mr = 48%) by KH at ambient temperature in toluene or THF, highly isotactic it ‐PFMA ( mm = 97%) by lithium ester enolate LiOC(O i Pr) = CMe 2 at −78 °C in toluene, and moderately syndiotactic st ‐PFMA ( rr = 70%) by LiOC(O i Pr) = CMe 2 in the presence of an aluminum Lewis acid at −78 °C in THF . Regarding organopolymerization methods, we reported zwitterionic polymerization of FMA at ambient temperature initiated by an N ‐heterocyclic carbene, 1,3‐di‐ tert ‐butylimidazolin‐2‐ylidene, forming a syndio‐biased atactic PFMA material with mm = 4.7%, mr = 35.1%, rr = 60.2% …”

Upgrading the chemistry of π-conjugated polymers toward more sustainable materials

“…109 Furanbased polymers can also be obtained by polymerizing a methacrylate furan-based compound, leading to polymers with furan as a pendant group. 110 5-HMF can be derivatized as a dicarboxylic furan (Furan-2,5-dicarboxylic acid, FDCA, in Figure 12); 111 the latter led to various polyesters with promising properties that rival those of petroleumbased plastics. 112,113,114 However, in these examples the πconjugated structure of furan is not fully exploited.…”