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In the continuing effort towards reducing reliance on fossil resources, the transition to biobased materials is of utmost importance, together with the adoption of more sustainable and safe production processes. This work focuses on the implementation of renewable resources and greener protocols for the synthesis of a bio-based amino crosslinker and its subsequent use in non-isocyanate polyurethane (NIPU) synthesis. NIPUs are a new class of materials, analogous to isocyanate derived polyurethanes (PUs), that avoid hazardous chemicals in their production process, such as phosgene and isocyanates, that raise high concern in the PU manufacturing processes. Vegetable oils and lignin are two abundant renewable feedstocks largely investigated during the last decade. In this paper, we study the synthesis of a high oleic sunflower oil derived polyamine (PA) via thiol–ene photoreaction in batch and in flow. Additionally, cyclic carbonate functionalized lignin (CCLF) was synthesized and reacted with PA to create fully bio-based NIPU networks with different lignin contents. The curing behavior as well as the characterization of the obtained thermosets is described. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) foams are key players within the large foam market, with applications such as thermal insulating materials, cushioning, protective equipment, etc. With the current regulatory constraints on the use of toxic isocyanates and the ambitious goals to increase the renewable content of plastics while valorizing waste, isocyanate-free liquid formulations containing biofillers that are able to easily self-foam are needed for more sustainable PU foams in the future. Herein, we incorporate various abundant waste stream-sourced biofillers (proteins, lignin derivatives, and polysaccharides) into isocyanate-free PU formulations composed of CO2-based poly(cyclic carbonate)s, diamines and a catalyst. The formulations containing up to 30 wt% of biofillers are foamed at 100 °C without adding any external foaming agent. Moisture naturally present in the biofillers partially hydrolyses the cyclic carbonates, which generates the blowing agent (CO2). The biofiller, even at a low content (1 wt%), stabilizes the growing cells, providing homogeneous foams. Although the nature of the biofiller does not significantly affect the foams' density and morphology, their mechanical properties are strongly affected, for example from a rigid foam with 10 wt% keratin (compression modulus (E) = 21.9 MPa) to a flexible one with chitosan (E = 0.2 MPa). Preliminary studies indicate that the biofiller does not prevent the foam recycling into polymer films by hot pressing. Virtually any kind of moisture-containing biowaste can be used as a water reservoir to foam the formulations while increasing the bio-based content of the material, which reaches 97% when selecting bio-based monomers. This process valorizes abundant waste stream-sourced biofillers for producing more sustainable PU foams. [ABSTRACT FROM AUTHOR]

Widely available vegetable oils were readily derivatized into chemically pure ABn-type monomers (n = 2 or 3). Their polymerization led to unprecedented hyperbranched polyesters. Four different AB2/AB3-type monomers bearing one A-type methyl ester and two or three B-type alcohol functions were purposely synthesized via two elementary steps, i.e. epoxidation of the internal double bond of the vegetable oil precursors followed by ring-opening of the epoxy groups under acidic conditions. The polycondensation of these bio-sourced monomers was performed in bulk, in the presence of an appropriate catalyst, giving access to modular hyperbranched polyesters with tunable properties. Among the catalysts tested, zinc acetate, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and sodium methoxide proved the most effective, allowing the achievement of molar masses in the range 3000–10 000 g mol−1 and dispersities varying from 2 to 15, depending on the initial conditions. The degree of branching, DB, as determined by 1H NMR spectroscopy, was found to be between 0.07 and 0.45. The as-devised hyperbranched polyesters displayed either amorphous or semi-crystalline properties, as a function of the selected AB2/AB3-type initial monomers, with a glass transition temperature, Tg, ranging from −33 to 9 °C and a decomposition temperature at 5 wt% of the sample, Td5%, varying from 204 to 340 °C. [ABSTRACT FROM AUTHOR]

Selective catalytic carbonylation of the trisubstituted double bond of citronellic acid is enabled via an isomerization-functionalization approach. Alkoxycarbonylation with [{1,2-(tBu2PCH2)2C6H4}- Pd(OTf) 2] as a catalyst precursor occurs with >97% selectivity for the terminal diester dimethyl-3,7-dimethylnonane-dioate. This prevails much over the typical cationic methoxyaddition. The reactive primary carboxy group formed allows for e.g. the preparation of the high molecular weight novel polyester poly[3,7-dimethylnonanediyl- 3,7-dimethylnonanedioate]. [ABSTRACT FROM AUTHOR]

Castor oil and vernonia oil platforms were used to synthesize two linear and branched α,ω-diene monomers. ADMET copolymerization conducted in bulk yielded a series of copolyesters with various degrees of branching with respect to the feed ratio between the two α,ω-dienes. After hydrogenation, these copolyesters showed thermo-mechanical properties in accordance with the ones of LLDPE and VLDPE with tunable melting points between 50 °C and 90 °C. As expected, and similarly to the "PElike" polyesters reported in the literature, the presence of ester functions distributed along the polyethylene backbone slightly lowered the crystalline ability of the so-formed polyesters. Nevertheless, these novel bio-based polyesters constitute a good sustainable alternative to olefin-based elastomers (LLDPE and VLDPE), especially for specific applications which require degradability. [ABSTRACT FROM AUTHOR]