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Cell attachment after 1 day and after 2 days (above, left, and right) as well as viability tests (below) of HaCat cells on different PinA6/ PEG surfaces (blends). For further figures see Supporting Information.
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Sustainable lactams, which are derived from terpenes, are used for the synthesis of different novel copolymers via ring‐opening polymerization. Different conditions are tested and the incorporation of the different monomers into the polymers is elucidated. This gives access to a variety of new polymer structures and their application range is thus...
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... HaCat cells were seeded onto them, incubated for a certain time (1 and 2 days) and then investigated via, for example, light microscopy and viability assays (e.g., with MTT, a tetrazolium salt (dye) which is metabolized to the corresponding formazan compound only by living cells; hence, absorption directly correlates with cell viability). Interestingly, cell attachment and viability on the PinA6/ PEG blends are very good, get better with increasing PEG content and can also be influenced via surface composition and roughness ( Figure 3 and Figure S96, Supporting Information). ...
Citations
... Due to their structure, PEAs have the characteristics of being both biodegradable and biocompatible, in addition to their elevated robustness resulting from their improved mechanical and thermal properties provided by the polyamide (PA) portions. These copolymers meet the leading requirements in terms of applications, which are of excellent value, particularly in the biomedical field, where they can be used to produce drug support matrices [12,13]. ...
The synthesis of polyesters and polyamides by enzyme-catalyzed processes in vitro was developed in the last decades as a green alternative to obtain biodegradable synthetic polymers with various applications, such as nanoparticle-sized carriers for drug delivery. Polyesteramides were much less studied in this respect, although having the presumable advantage of increased mechanical and thermic resistance brought by the amide moieties. In this work, polyesteramides were synthesized for the first time employing as raw materials ε-caprolactam and a hydroxy acid. L-malic, 3-hydroxybutyric, 12-hydroxystearic and 16-hydroxyhexadecanoic acid, respectively, were investigated as co-monomers in solventless or organic medium, using the immobilized lipase Novozyme 435 as catalyst. The short chain hydroxy acids holding secondary hydroxyl groups yielded oligomers with average degree of polymerization no higher than 4, while in the case of the long-chain 12-hydroxystearic acid this value increased to 7. The best results were achieved by using 16-hydroxyhexadecanoic acid in 2:1 M excess at 80 °C, yielding a product with 75% copolymer content and average molecular weight higher than 3000 Da. The emulsion-solvent evaporation method allowed the efficient production of nanoparticles based on this copolymer, with sizes around 230 nm, used for the encapsulation of a model bioactive compound, the anticancer drug sorafenib. Production yields of >70% and encapsulation efficiencies of around 60% are very promising for further development of this approach.
... Especially, the synthesized sustainable polymers could be precisely constructed at a molecular level in a way similar to their analogues derived from petroleum chemicals, and has been an active topic in both industry and academia. [12][13][14][15][16] Conjugated dienes (alkenes with two double bonds separated by a single bond) can be polymerized to form essential compounds like rubber which are involved in a broad range of applications. For example, polydienes, especially polyisoprene rubber (PI) is a synthetic analogue of nature rubber, while copolymers consisted of 1,3-butadiene and styrene is the most prevalent synthetic rubber SBR. ...
The reliance of both our life and industry on fossil resource and the alarming accumulation of polymeric materials in the environment have presented huge challenges to sustainable society. Nowadays, utilization of renewable monomers as building blocks for polymeric materials has emerged as a hot topic and increasingly gained attention from chemists. As a class of biomass with abundance and low cost, terpenes are typical hydrocarbon‐rich natural compounds, and some of them, such as myrcene and farnesene, are inherently suitable for coordination polymerization. In this review, we focus on the rare‐earth metal catalyzed highly regio‐ and stereoselective polymerization of bio‐based conjugated dienes, especially the ones from terpene‐derived compounds with or without modifications. This review also discusses the future direction on the modification of these bio‐based conjugated dienes.
... These lactams can also be copolymerized with other lactams to obtain copolyamides or e.g., with lactones to obtain polyesteramides [313][314][315]. Therefore, the properties of these polymers can be finely tuned via the copolymer composition and chain length. ...
Polyamides are very important polymers for a wide range of applications. In the context of Green Chemistry and the development of sustainable polymers from renewable resources, many polyamides have meanwhile been developed that are derived from natural building blocks. In addition to sustainability, biobased polyamides can have special structures and properties that cannot be obtained so easily via fossil-based pathways. This article gives an overview over the recent developments in this field and elucidates the potential of these polymers for different applications.KeywordsHigh-performance polymersPolyamidesPolycondensationRing-opening polymerizationSustainable polymers
... 30,34 Using anionic ring-opening polymerization (aROP) those lactams can be converted to the respective polyamides, which have been described thoroughly in recent years. 30,[33][34][35][36] A similar pathway can be selected to generate the lactones, involving a Baeyer-Villiger oxidation of ketones, targeting polyester synthesis via catalytic ring-opening polymerization (cROP). However, compared to the lactams, the lactones are far from being described entirely, mainly due to difficulties regarding the Baeyer-Villiger oxidation as key step. ...
Utilizing renewable feedstocks for the synthesis of biobased and preferrable biodegradable polyesters as substitute for fossile-based polymers remains one of the major challenges towards a sustainable polymer economy. One such...
... Fortunately, nature offers many different compounds, which are excellent building blocks for constructing advanced materials: polysaccharides and their derivatives, lignin, suberin, vegetable oils, tannins, monomers originating from sugars, furan derivatives, lactic acid and fatty acid, which are just a few examples [5,6]. In this context, the large family of terpenes represents a natural, potentially important source of unsaturated hydrocarbons, useful in producing polymers [7][8][9][10][11]. Terpenes are ubiquitous molecules, characterized by the presence of one or more double bonds, found in many plants (mainly conifers), fungi and even some insect, which have both linear and cyclic structures and share 2methyl-1,4-butadiene (isoprene) (C5) as an elementary unit [12]. ...
... Head-to-head and tail-to-tail enchainments bridge of 1,4-cis M additions (see Figure S3 in detail, SI), previously observed in the PM, were also visible in all 13 C { 1 H} spectra of PMS copolymers. Glass transition temperatures of PMS (runs [10][11][12][13][14] lie between that of the homopolymers (−76.5 and 105.5 °C for polymyrcene and atactic polystyrene, respectively) and are listed in Table 2. All the copolymers, with the exception of run 21, showed a single Tg value which decreased with increasing amount of M incorporated in the copolymers. ...
... Head-to-head and tail-to-tail enchainments bridge of 1,4-cis M additions (see Figure S3 in detail, SI), previously observed in the PM, were also visible in all 13 C { 1 H} spectra of PMS copolymers. Glass transition temperatures of PMS (runs [10][11][12][13][14] lie between that of the homopolymers (−76.5 and 105.5 • C for polymyrcene and atactic polystyrene, respectively) and are listed in Table 2. All the copolymers, with the exception of run 21, showed a single T g value which decreased with increasing amount of M incorporated in the copolymers. ...
Soluble heterocomplexes consisting of sodium hydride in combination with trialkylaluminum derivatives have been used as anionic initiating systems at 100 °C in toluene for convenient homo-, co- and ter-polymerization of myrcene with styrene and isoprene. In this way it has been possible to obtain elastomeric materials in a wide range of compositions with interesting thermal profiles and different polymeric architectures by simply modulating the alimentation feed and the (monomers)/(initiator systems) ratio. Especially, a complete study of the myrcene-styrene copolymers (PMS) was carried out, highlighting their tapered microstructures with high molecular weights (up to 159.8 KDa) and a single glass transition temperature. For PMS copolymer reactivity ratios, rmyr = 0.12 ± 0.003 and rsty = 3.18 ± 0.65 and rmyr = 0.10 ± 0.004 and rsty = 3.32 ± 0.68 were determined according to the Kelen–Tudos (KT) and extended Kelen–Tudos (exKT) methods, respectively. Finally, this study showed an easy accessible approach for the production of various elastomers by anionic copolymerization of renewable terpenes, such as myrcene, with commodities.
... Further to that, the interaction of human keratinocytes (HaCat cells) with films of poly-j blended with poly-ethylene glycol has been examined, demonstrating the potential of biobased polyamides in biomedical applications such as regenerative skin replacement. 177,178 In 2019, Sieber and co-workers achieved the ROP of β-lactams k2 and k3, and ε-lactams k1-4 obtained from α-pinene and (+)-carene, respectively (Fig. 29). 179 The β-lactams k2 and k3 were synthesised by [2 + 2] cycloaddition of chlorosulfonyl isocyanate to either α-pinene or (+)-carene. ...
Our dependence on fossil-fuel based raw materials and alarming plastics accumulation in the environment has inspired many scientists to design and implement more sustainable approaches for polymer synthesis. The identification and assessment of new and renewable biobased monomers has become a major topic of interest en route to a circular economy. In this respect, terpenes and terpenoid scaffolds have attracted much attention due to their ubiquitous nature and high functionality. This minireview uncovers recent advancements in the synthesis of terpene-based polymers, and specifically discusses the formation of terpene-derived polycarbonates, polyesters, polyurethanes and polyamides. The potential of these polymers in post-synthetic curing and modifications is also highlighted to illustrate the opportunities that exist to develop new polymer formulations beyond bench scale.
Polyamides (PA) are among the most essential and versatile polymers due to their outstanding characteristics, e.g., high chemical resistance and temperature stability. Furthermore, nature‐derived monomers can introduce hard‐to‐synthesize structures into the PAs for unique polymer properties. Pinene, as one of the most abundant terpenes in nature and its presumable stability‐giving bicyclic structure, is therefore highly promising. This work presents simple anionic ring‐opening polymerizations of β‐pinene lactam (AROP) in‐bulk and in solution. PAs with high molecular weights, suitable for further processing, were produced. Their good mechanical, thermal (T d s up to 440°C), and transparent appearance render them promising high‐performance biomaterials. In the following, the suitability of different initiators is discussed. Thereby, it was found that NaH was the most successful for in‐bulk polymerization, with a degree of polymerization (DP) of 322. For solution‐AROP, i PrMgCl·LiCl was successfully used for the first time, achieving DPs up to 163. The obtained PAs were also hot‐pressed, and the dynamic mechanical properties were analyzed.
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Polyamides are very important polymers, with applications from commodities up to high‐performance materials for, for example, fibers or for the biomedical sector. Nowadays, still most of them are synthesized from fossil resources. With regards to sustainability and bioeconomy, and especially regarding the new structures and properties that can thus be achieved, the preparation of polyamides (PAs) from natural precursors is getting more and more important. For this, especially the utilization of terpenes, a large and important group of natural products with different functions in nature (regulators, defense signals, etc.), is important, which is described herein. Similar approaches are interesting from a scientific point of view regarding, for example, structure‐function‐relations, but also with regards to different applications as, for example, high‐performance or biomedical materials.
Practical applications : Terpene‐based polyamides can find many applications, from commodities up to high‐performance fibers and special materials in (bio)medicine, for example, drug delivery, tissue engineering, etc.
The field of sustainable polymers from renewable feedstocks is a fast-reviving field after the decades-long domination of petroleum-based polymers. Amide-containing polymers exhibit a wide range of properties depending on the type of amide (primary, secondary, and tertiary), amide density, and other molecular structural parameters (co-existing groups, molecular weight, and topology). Engineering amide groups into sustainable polymers via the "monomer approach" is an industrially proven strategy, while bio-based monomers are of enormous importance to bridge the gap between renewable sources and amide-containing sustainable polymers (AmSPs). This feature article aims at conceptualizing the monomer-design philosophy behind most of the reported AmSPs and is organized by discussing di-functional monomers for step-growth polymerization, cyclic monomers for ring-opening polymerization and amide-containing monomers for chain-growth polymerization. We also give a perspective on AmSPs with respect to monomer design and performance enhancement.
