We report a systematic FTIR study of the perturbation of water “sorbed” into the polymers PET and PVC as a function of crystallinity (PET) or plasticizer content (PVC). Band shapes of the composite ν(OH) band of H2O obtained by the ATR technique have been fitted to individual components,corresponding to those recently found for pure water itself. A detailed quantitative analysis of the frequency shifts and relative intensties has led to conclusion that these component bands show direct evidence for the breaking of the water network in the polymer matrix and that this process depends on the polymer chemical and/or physical properties. Evidence is also found for interactions of water with the polymer at the lower end of the hydrogen bond interaction scale. The component band relative intensities (compared with those of pure water) have been used to compute an intensity enhancement parameter, P, which is a measure of the perturbation of a particular water distribution due to dissolution in the polymer matrix. For PET, P varies systematically with density, reflecting the ability of water to penetrate the polymer microstructure. For PVC the plasticizer content (and hence T g) has a considerable influence on the sorption (and swelling) process and on the equilibrium content and state of water. Thus, ATR-FTIR has been used for the first time to demonstrate,via intensity enhancement, the extent of electronic perturbation at a polymer/water interface.

Highly sustainable composites were produced by melt compounding polylactide (PLA) with almond shell flour (ASF), a processed byproduct of the food industry, at a weight content of 30 wt.-%. However, due to the lack of miscibility between PLA and ASF, both being raw materials obtained from crops, resultant green composite presented poor ductility and low thermal stability. To overcome this limitation, maleinized linseed oil (MLO), a multi-functionalized plant-derived additive, was originally incorporated as a reactive compatibilizer during the extrusion process. Both chemical and physical characterizations showed that 1-5 parts per hundred resin (phr) of MLO successfully serve to function as a novel compatibilizer on the PLA/ASF composites, leading to highly sustainable materials with balanced mechanical, thermal, and thermomechanical properties. Achieved compatibilization was particularly related to a dual effect of plasticization in combination with grafting. The latter effect was ascribed to the formation of new carboxylic ester bonds through the reaction of the multiple maleic anhydride groups present in MLO with the hydroxyl terminal groups of both PLA chains and lignocellulose on the ASF surface. The fully bio-based and 2 biodegradable composites described herein give an efficient sustainable solution to upgrade agrofood wastes as well as contributing to reducing the cost of PLA-based materials.

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Progress in mesenchymal stem cell (MSC) based therapies for nucleus pulposus (NP) regeneration are hampered by a lack of understanding and consensus of the normal NP cell phenotype. Despite the recent consensus paper on NP markers, there is still a need to further validate proposed markers. This study aimed to determine whether an NP phenotypic profile could be identified within a large population of mature NP samples.qRT-PCR was conducted to assess mRNA expression of 13 genes within human non-degenerate articular chondrocytes (AC) (n=10) and NP cells extracted from patients across a spectrum of histological degeneration grades (n=71). qRT-PCR results were used to select NP marker candidates for protein expression analysis.Differential

9Poly lactide-co-glycolide (PLGA) is an important polymer matrix used to provide sustained 10 release across a range of active pharmaceutical ingredients (APIs) and works by hydrolytic 11 degradation within the body, thereby releasing entrapped drug. Processing and sterilisation 12 can impact on the morphology and chemistry of PLGA therefore influencing the hydrolysis 13 rate and in turn the release rate of any entrapped API. This paper has looked at the effect of 14 supercritical carbon dioxide (scCO 2 ) processing, gamma irradiation, comonomer ratio and 15 temperature on the hydrolysis of individual PLGA microparticles, using a combination of 16 Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) imaging, Scanning 17 Electron Microscopy (SEM), Differential Scanning Calorimetery (DSC) and Gel Permeation 18 chromatography (GPC) to facilitate a better understanding of the physiochemical factors 19affecting the hydrolysis rate. This work has shown that scCO 2 processing influences 20 hydrolysis rates by increasing the porosity of the PLGA microparticles, increasing the lactide 21 comonomer ratio decreases hydrolysis rates by reducing the hydrophilicity of the PLGA 22 microparticles and increasing the gamma irradiation dose systematically increases the rate of 23 hydrolysis due to reducing the overall molecular weight of the polymer matrix via a chain 24 scission mechanism. Moreover this work shows that ATR-FTIR imaging facilitates the 25 determination of a range of physicochemical parameters during the hydrolysis of a single 26 PLGA microparticle including water ingress, water/polymer interface dimensions, 27 degradation product distribution and hydrolysis rates for both lactide and glycolide 28 copolymer units from the same experiment. 29