Polyamides based on a partially bio-based spirodiamine

In this study novel, fully and partially bio-based polyamides containing spiroacetal moieties in the backbone derived from bio-glycerol and bio-ethanol were prepared and characterized. The renewable diamine employed to obtain a series of polyamides was synthesized by means of thiolene click chemistry and therefore contains flexible thioether as well as rigid spiroacetal moieties. Two different chemical pathways for the polymerization were investigated and evaluated. The polymerization of polyamide salts proved to be the most promising method and therefore salt polymerization was applied in the synthesis of polyamides with aliphatic and aromatic di-carboxylic acids. Subsequently, the structure of the polymers was confirmed by Maldi-ToF analysis and additionally thermal and mechanical properties were investigated revealing T-g's between 24 and 80 degrees C and ductile materials with moduli between 1.0 and 1.5 GPa. Both semicrystalline and amorphous polyamides were thermally stable and therefore suitable for thermal processing. In the end, degradation studies were performed on the acetal containing polyamides which showed that the polymers were stable at pH 3 and higher

MacroRAFT agents from renewable resources and their use as polymeric scaffolds in a grafting from approach

Amphiphilic graft copolymers, based on renewable resources, were synthesized via a "grafting from" strategy. First, a linear hydroxyl functionalized aliphatic polyester, the monomer of which was a fatty acid derivative, was synthesized by a stepwise polymerization. Secondly, trithiocarbonate side groups were attached to the prepared polymer. Finally, a grafting from reversible addition-fragmentation chain transfer (RAFT) polymerization was executed on the macroRAFT agent with the aim to introduce poly(acrylic acid) grafts. The polymers prepared thereof were characterized by nuclear magnetic resonance spectroscopy, size exclusion chromatography and Fourier transform infrared spectroscopy. In order to show the amphiphilic character of those graft copolymers, micelle formation tests were carried out and measured with dynamic light scattering while emulsifying properties were studied via an emulsion stabilization test

High molecular weight poly(cycloacetals) towards processable polymer materials

Processable poly(cycloacetals) with high molar masses (M-n) up to 38 kDa were synthesized in a systematic manner. Di-trimethylolpropane (Di-TMP) was used as tetravalent alcohol and was combined with a series of available dialdehydes, after a model reactivity study. These polymers have a high thermal stability with degradation temperatures (T-d) up to 370 degrees C while the glass transition temperatures (T-g) ranged from room temperature to 115 degrees C. Trends in T-g modulation were confirmed by a theoretical simulation. Moreover, the poly(cycloacetals) showed favourable mechanical and optical properties. (C) 2016 Elsevier Ltd. All rights reserved