To facilitate the ongoing transition toward a circular economy, the availability of renewable materials for additive manufacturing becomes increasingly important. Here, we report the successful fabrication of complex shaped prototypes from biobased acrylate photopolymer resins, employing a commercial stereolithography apparatus (SLA) 3D printer. Four distinct resins with a biobased content ranging from 34 to 67% have been developed. All formulations demonstrated adequate viscosity and were readily polymerizable by the UV-laser-based SLA process. Increasing the double-bond concentration within the resin results in stiff and thermally resilient 3D printed products. High-viscosity resins lead to high-resolution prototypes with a complex microarchitecture and excellent surface finishing, comparable to commercial nonrenewable resins. These advances can facilitate the wide application of biobased resins for construction of new sustainable products via stereolithographic 3D printing methods.

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SYNOPSISPoly(ethylene-2,6-naphthalenedicarboxylate)(PEN) has been prepared from commercial dimethyl-2,6-naphthalenedicarboxylate (DM-2,6-NDC) and ethylene glycol (EG) according to the well-known transesterification/polycondensation route. P E N fibers, intended for industrial yarn applications, were obtained by melt spinning and drawing high molecular weight PEN. The properties of these yarns were measured in detail and compared with those of P E T industrial yarns. The development of molecular orientation in the spinline is more pronounced for PEN than for PET. Because the yield stress is lower, P E N yarns can more easily be drawn. Breaking tenacities of PEN yarns are comparable with those of P E T yarns, but the modulus is much higher and the thermal shrinkage is lower. Therefore, P E N yarns have a better dimensional stability than PET yarns. In addition, it was demonstrated that the thermal resistance of P E N yarns is better. 0 1995 John Wiley & Sons, Inc.

Please cite this article as: Jäger, J., Sause, M.G.R., Burkert, F., Moosburger-Will, J., Greisel, M., Horn, S., Influence of plastic deformation on single-fiber push-out tests of carbon fiber reinforced epoxy resin, Composites: Part A (2015), doi: http://dx. AbstractIn our study we present a procedure to measure and analyze single-fiber push-out force-displacement curves on carbon fiber reinforced polymers using a cyclic loading-unloading scheme. The measured cyclic force-displacement curves allow an energy-based evaluation of the interfacial failure, taking into account elastic, plastic and other dissipative energy contributions. Experimental and modeling results demonstrate that a deviation of the push-out curve from linear behavior does not correspond to crack opening but to a plastic deformation of the matrix. Evaluating the plastic energy yields a linear increase of the total plastic energy after a certain indenter displacement. This linear increase is attributed to stable crack propagation.Back-extrapolation of the linear part to zero total plastic energy using a linear regression yields the initiation of crack growth. It is concluded that for ductile matrix materials like polymers, a reliable interpretation of push-out data has to take into account plastic material deformation.

Rate constants for neutral hydrolysis of p-methoxyphenyl dlchloroacetate in aqueous solutions are sensitive to the molality of added urea and alkyl-substituted ureas. These dependences are considered in the light of pairwise Gibbs function parameters describing interaction between solutes in aqueous solutions. In the next stage these interactions are examined by using the Savage-Wood additivity principle for pairwise group interaction parameters involving organic solutes and both initial and transition states for the hydrolysis reaction. The basis of the approach is described showing how kinetic and thermodynamic data are drawn together and used to comment on mechanisms of reaction in aqueous solutions. For the hydrolysis of the dlchloroacetate ester, we account for the observed dependence of rate constant on solvent in terms of a reaction that is second order with respect to water, where the transition state exposes three OH groups to the aqueous solution, and in terms of derived group interaction parameters involving these OH groups and both CH2 and CONH groups in added solutes.

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o, 2017. Impact of coupled support for sugar beet growing in the EU: More sugar beets and lower sugar beet price. Wageningen, Wageningen Economic Research, Report 2017-114. 62 pp.; 12 fig.; 11 tab.; 16 ref. Sinds de onderhandelingen over het 'nieuwe GLB' (Gemeenschappelijk Landbouwbeleid van de EU) is het mogelijk vrijwillige gekoppelde steun (voluntary coupled support, VCS) aan de teelt van suikerbieten te geven. Sinds 2015 maken tien en sinds 2017 elf EU-lidstaten daar gebruik van. In 2017 werd het EU suikerquotasysteem afgeschaft. Dat is een grote verandering voor de EU suikersector, die tot meer concurrentie tussen suikerbedrijven leidt en tot sterker variërende suikerprijzen dan voorheen. In een dergelijke dynamische context zijn vragen gesteld over de mogelijke productie-en marktverstorende effecten en de legitimiteit van een VCS-regeling.In the 2013 negotiations on the 'new CAP' (Common Agricultural Policy), the option of voluntary coupled support (VCS) for sugar beet growing was introduced, which has been implemented from 2015 onwards by ten and from 2017 by eleven Member States. In 2017, a great change took place in the EU sugar sector through the abolishment of the sugar quota system, leading to an increase of competition between sugar companies and more fluctuating sugar prices than before. In such a dynamic context, questions were raised about potentially destabilising production and market effects of a VCS-regulation and about its legitimacy.