Isomerizing alkoxycarbonylation of methyl oleunsaturated fatty acids ~ ~ ate and ethyl erucate, respectively, yielded dimethyl 1,19-~gH R /1 " "-. R nonadecanedioate and diethyl 1,23-tricosanedioate in >99% ./' ""'purity. With [K 2-(PP)Pd(OTf)][OTf] as a defined catalyst 0 0 A HO~OH H~H precursor (pp = 1,2-bis[(di-tert-butylphosphino)methyl]ben-t=~ II zene) the reaction can be carried out without the need for ~ • + additional added diphosphine. Saponification of the diesters H2N~NH2 yielded 1,19-nonadecanedicarboxylic acid and 1,23-tricosane-E3. I dicarboxylic acid in >99% purity. By ruthenium-catalyzed reduction of the diesters with H 2 , 1,19-nonadecanediole and 1,23-tricosanediole were formed in high yield and purity (>99%). From the latter, 1,19-nonadecanediamine and 1,23-tricosanediamine were generated. Polyesters with commercially available shorter-chain petrochemical or renewable diols exhibit high melting points due to the crystallizable long-chain methylene segments from the dicarboxylic acid component, e.g., poly[ 1,6-hexadiyl-1,23-tricosanedioate] Tm 92, Tc 7S 0c, Thermal properties of novel long-chain polyamides are reported .

The passage of time from laboratory demonstration of a technology-enabling efficiency value and until methodology and preparative means are in place is explored in this work for the polymer solar cell. Long technical strides need to be taken and efforts much beyond the laboratory solar cell need to be dedicated to bringing new solar cell material discoveries to service as an industrial technology. This includes scaled materials preparation, scaled manufacturing platforms, scaled installation platforms, as well as scaled electronics, monitoring, and control systems. We epitomize this as the ''scaling lag'' and highlight its importance when wishing to progress new solar cell materials from science to technology. The scaling gap is an observable element that can be extracted directly from experimental data and can be taken as a sign of technological maturity that can aid early-phase investors in their decision of when to invest in product development based on new technology.

Long-chain polyacetals and polycarbonates were prepared by polycondensation of α,ω-diols (C 18 , C 19 , C 23 ) derived from fatty acids as a renewable feedstock with diethoxymethane and dimethyl carbonate, respectively, in one step. Studies of hydrolytic degradation of the solid polymers show a much higher stability compared to their shorter-chain counterparts. Long-chain polyacetals were found to degrade slowly under acidic conditions, while the long-chain polycarbonates also degraded in a basic environment. To rationalize the impact of acetal and carbonate groups on the thermal and crystalline properties of polyacetals and polycarbonates, additional model polymers with a further reduced and systematically varied functional group density were generated by ADMET copolymerization of the unfunctionalized undeca-1,10-diene with bis(undec-10-en-1-yloxy)methane or di(undec-10-en-1-yl) carbonate, respectively, followed by exhaustive hydrogenation. Long-chain polycarbonates possess polyethylene-like solid state structures. By comparison to polyesters, a given density of carbonate groups in the polymer chain reduces melting and crystallization temperatures significantly more strongly. By contrast, long-chain polyacetals possess more complex non-uniform crystal structures, and only adopt a polyethylene-like structure at very low densities of acetal groups. Also, acetal groups more strongly impact melting and crystallization temperatures vs. carbonates. † Electronic supplementary information (ESI) available: Details on synthetic procedures and degradation studies, characterization methods and DSC, IR and WAXD data for long-chain polyacetals (PA-18, PA-19, PA-23) and polycarbonates (PC-18, PC-19, PC-23) as well as for randomly long-spaced polyacetals (PA-50.0H to PA-0.0H) and polycarbonates (PC-50.0H to PC-0.0H) are given. See

The results presented demonstrate how the screening of 104 light‐absorbing low band gap polymers for suitability in roll coated polymer solar cells can be accomplished through rational synthesis according to a matrix where 8 donor and 13 acceptor units are organized in rows and columns. Synthesis of all the polymers corresponding to all combinations of donor and acceptor units is followed by characterization of all the materials with respect to molecular weight, electrochemical energy levels, band gaps, photochemical stability, carrier mobility, and photovoltaic parameters. The photovoltaic evaluation is carried out with specific reference to scalable manufacture, which includes large area (1 cm2), stable inverted device architecture, an indium‐tin‐oxide‐free fully printed flexible front electrode with ZnO/PEDOT:PSS (poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate), and a printed silver comb back electrode structure. The matrix organization enables fast identification of active layer materials according to a weighted merit factor that includes more than simply the power conversion efficiency and is used as a method to identify the lead candidates. Based on several characteristics included in the merit factor, it is found that 13 out of the 104 synthesized polymers outperformed poly(3‐hexylthiophene) under the chosen processing conditions and thus can be suitable for further development.

This review summarizes the recent progress in the stability and lifetime of organic photovoltaics (OPVs). In particular, recently proposed solutions to failure mechanisms in different layers of the device stack are discussed comprising both structural and chemical modifications. Upscaling is additionally discussed from the perspective of stability presenting the challenges associated with device packaging and edge protection. An important part of device stability studies is the characterization and the review provides a short overview of the most advanced techniques for stability characterization reported recently. Lifetime testing and determination is another challenge in the field of organic solar cells and the final chapters discuss the testing protocols as well as the generic marker for device lifetime and the methodology for comparing all the lifetime landmarks in one common diagram. These tools were used to determine the baselines for OPV lifetime tested under different ageing conditions. Finally, the current status of lifetime for organic solar cells is presented and predictions are made for the progress in near future.

The identification of a unique set of advanced materials that can bear extraordinary loads for use in bone and tooth repair will inevitably unlock unlimited opportunities for clinical use. Herein, the design of high‐performance thermosets is reported based on triazine‐trione (TATO) monomers using light‐initiated thiol‐yne coupling (TYC) chemistry as a polymerization strategy. In comparison to traditional thiol‐ene coupling (TEC) systems, TYC chemistry has yielded highly dense networks with unprecedented mechanical properties. The most promising system notes 4.6 GPa in flexural modulus and 160 MPa in flexural strength, an increase of 84% in modulus and 191% in strength when compared to the corresponding TATO system based on TEC chemistry. Remarkably, the mechanical properties exceed those of polylactide (PLA) and challenge poly(ether ether ketone) PEEK and today's methacrylate‐based dental resin composites. All the materials display excellent biocompatibility, in vitro, and are successfully: i) molded into medical devices for fracture repair, and ii) used as bone adhesive for fracture fixation and as tooth fillers with the outstanding bond strength that outperform methacrylate systems used today in dental restoration application. Collectively, a new era of advanced TYC materials is unfolded that can fulfill the preconditions as bone fixating implants and for tooth restorations.

The stability of polymer solar cells (PSCs) can be influenced by the introduction of particular moieties on the conjugated polymer side chains. In this study, two series of donor-acceptor copolymers, based on bis(thienyl)dialkoxybenzene donor and benzo[c][1,2,5]thiadiazole (BT) or thiazolo[5,4-d]thiazole (TzTz) acceptor units, were selected toward effective device scalability by roll-coating. The influence of the partial exchange (5% or 10%) of the solubilizing 2-hexyldecyloxy by alternative 2-phenylethoxy groups on efficiency and stability was investigated. With an increasing 2-phenylethoxy ratio, a decrease in solar cell efficiency was observed for the BT-based series, whereas the efficiencies for the devices based on the TzTz polymers remained approximately the same. The photochemical degradation rate for PSCs based on the TzTz polymers decreased with an increasing 2-phenylethoxy ratio. Lifetime studies under constant sun irradiance showed a diminishing initial degradation rate for the BT-based devices upon including the alternative side chains, whereas the (more stable) TzTz-based devices degraded at a faster rate from the start of the experiment upon partly exchanging the side chains. No clear trends in the degradation behavior, linked to the copolymer structural changes, could be established at this point, evidencing the complex interplay of events determining PSCs’ lifetime.

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