The reaction pathways of several Friedel-Crafts acylations involving phenyl aromatic compounds were studied using density functional theory. The reactions were related to the Friedel-Crafts polycondensation of polyaryletherketones. In particular, the acylation of benzene with benzoyl chloride to form benzophenone and variations on this reaction were investigated. The acylation of benzene by one molecule of terephthaloyl chloride or isophthaloyl chloride as well as acylations at the m-, o-, and p-positions of diphenyl ether with one molecule of benzoyl chloride were studied. Adding an additional acyl chloride group to the electrophile appeared to have little influence on the reaction pathway, although the activation energy for the C-C bond-forming steps that occurred when isophthaloyl choride was used was different to the activation energy observed when terephthaloyl chloride was used. Upon changing the nucleophile to diphenyl ether, the reactivity changed according to the trend predicted on based on the o-, p-directing effects of the ether group. The deprotonation step that restored aromaticity varied widely according to the reaction. The rate-determining step in all of the studied reactions was the formation of the acylium ion, followed in importance by either the formation of the Wheland intermediate or the abstraction of hydrogen, depending on the reactivity of the nucleophile.

Known since antiquity, Castor Oil has been first used in medicine. Now, even if it remains present in small quantities as an excipient in many pharmaceutical specialties, it finds a lot of applications in cosmetics, industrial applications and chemical industry. Castor Oil specificity comes from its high content of ricinoleic acid (up to 85%) that combines a double bond and an hydroxyl function in the heart of a 18 carbons linear chain. This particular structure is the key of an unique chemistry developed by ARKEMA that gives by thermal cracking a wide range of compounds with either 7 or 11 carbon atoms. A whole range of innovative chemistries and end use products are generated from these base reaction products. They are used in every-day life, to improve our comfort and safety but also in very specific applications with very high technical requirements. Synthesized from undecylenic acid, 11-amino-undecanoic acid, 100% based on renewable resources, is the precursor to biobased polymers combining high performance and sustainability: Rilsan

Two ways to obtain aliphatic polyesters (PEs) from dimethylketene and acetaldehyde were investigated. On the one hand, a direct anionic copolymerization was carried out in toluene at À60 C. The resulting polymer was mainly composed of PE units. On the other hand, a two-step process involving the synthesis of 3,3,4-trimethyl-2-oxetanone by [2þ2] cycloaddition, followed by its ring-opening polymerization, with various initiators and solvents, led to the expected PE. Molecular weights up to 9000 g mol À1 (measured by nuclear magnetic resonance (NMR)), with narrow polydispersity around 1.2, were obtained. These polymers were found stable up to 274 C under nitrogen and a broad and complex endothermic peak attributed to crystallinity was observed near 139 C by differential scanning calorimetry (DSC). The crystallinity, measured by X-ray diffraction, was close to 0.45.

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High-temperature laser sintering (HT-LS) is a very promising additive manufacturing process for the production of parts of complex geometry for highly demanding applications. Poly(aryl ether ketone) polymers such as poly(ether ketone), poly(ether ether ketone), and poly(ether ketone ketone) (PEKK) have attracted increasing interest during the last decade for use in HT-LS. Among them, PEKK offers the advantage of exhibiting tunable melting temperature and crystallization rate due to its copolymer structure. Indeed, PEKK is synthesized by Friedel−Crafts polyacylation condensation of diphenyl ether with terephthaloyl chloride (T units) and isophthaloyl chloride (I units). In this work, we focus on a specific member of the PEKK family having a regular alternated T/I structure, PEKK 50/50, and study its isothermal crystallization from the melt at various crystallization temperatures (T C ), from 200 °C to 290 °C. A quantitative analysis based on X-ray scattering and differential scanning calorimetry experiments is performed. Primary crystallization dominates the process with a half-time of crystallization higher than 6 min and an Avrami exponent between 2.2 and 3. Stacks of periodic crystalline lamellae are first created, followed by lateral growth of these crystalline lamellae, leading to a gradual increase of the weight crystallinity. Crystalline form I, with traces of form III, is mostly observed regardless of T C . The amount and perfection of the crystalline phase increase with T C . The crystalline state achieved, as well as the thermal and rheological behavior of PEKK 50/50 during crystallization at high T C (∼280−290 °C), are promising for use in HT-LS manufacturing.