How the Aliphatic Glycol Chain Length Determines the Pseudoeutectic Composition in Biodegradable Isodimorphic poly(alkylene succinate--caprolactone) Random Copolyesters.

We synthesize four series of novel biodegradable poly(alkylene succinate--caprolactone) random copolyesters using a two-step ring-opening/transesterification and polycondensation process with ε-caprolactone (PCL) as a common comonomer. The second comonomers are succinic acid derivatives, with variations in the number of methylene groups () in the glycol segment, = 2, 4, 8, and 12. The obtained copolyesters were poly(ethylene succinate--PCL) (ESCL), poly(butylene succinate--PCL) (BSCL), poly(octamethylene succinate--PCL) (OSCL), and poly(dodecylene succinate--PCL) (DSCL).

Scleroderma: oral, maxillofacial and radiographic manifestations for dental practitioners.

Scleroderma is an autoimmune condition of unknown aetiology with a range of manifestations, which can be limited to the skin or can extend to be multisystemic. It is characterised by fibrosis, microangiopathy and dysregulation of the immune system and commonly affects the oral cavity. Frequent oral and maxillofacial features include fibrosis of the face, circumoral furrows and reduced oral aperture.

Sequential Crystallization and Multicrystalline Morphology in PE--PEO--PCL--PLLA Tetrablock Quarterpolymers.

We investigate for the first time the morphology and crystallization of two novel tetrablock quarterpolymers of polyethylene (PE), poly(ethylene oxide) (PEO), poly(ε-caprolactone) (PCL), and poly(l-lactide) (PLLA) with four potentially crystallizable blocks: PE PEO PCL PLLA (Q1) and PE PEO PCL PLLA (Q2) (superscripts give number average molecular weights in kg/mol, and subscripts give the composition in wt %). Their synthesis was performed by a combination of polyhomologation (C1 polymerization) and ring-opening polymerization techniques using a ″catalyst-switch″ strategy, either ″organocatalyst/metal catalyst switch″ (Q1 sample, 96% isotactic tetrads) or ″organocatalyst/organocatalyst switch″ (Q2 sample, 84% isotactic tetrads). Their corresponding precursors-triblock terpolymers PEPEOPCL, diblock copolymers PEPEO, and PE homopolymers-were also studied.

Structure and Properties of Reactively Extruded Opaque Post-Consumer Recycled PET.

The recyclability of opaque PET, which contains TiO nanoparticles, has not been as well-studied as that of transparent PET. The objective of this work is to recycle post-consumer opaque PET through reactive extrusion with Joncryl. The effect of the reactive extrusion process on the molecular structure and on the thermal/mechanical/rheological properties of recycling post-consumer opaque PET (r-PET) has been analyzed.

Crystallization and Morphology of Triple Crystalline Polyethylene--poly(ethylene oxide)--poly(ε-caprolactone) PE--PEO--PCL Triblock Terpolymers.

The morphology and crystallization behavior of two triblock terpolymers of polymethylene, equivalent to polyethylene (PE), poly (ethylene oxide) (PEO), and poly (ε-caprolactone) (PCL) are studied: PE--PEO--PCL (T1) and PE--PEO--PCL (T2) (superscripts give number average molecular weights in kg/mol and subscripts composition in wt %). The three blocks are potentially crystallizable, and the triple crystalline nature of the samples is investigated. Polyhomologation (C1 polymerization), ring-opening polymerization, and catalyst-switch strategies were combined to synthesize the triblock terpolymers.