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A technique for poly-3-hydroxybutyrate (P(3HB)) extraction with safer, non-chlorinated solvents, was developed, aiming to attain high recovery yields and purities. A wide range of solvents was selected from the GlaxoSmithKline guide as sustainable industrial solvents and the solubility of P(3HB) on those solvents calculated using predictive equations from literature. Anisole, * Corresponding author: Tel.: +351 21 8419137; Fax: +351 21 8419062. e-mail address: teresa.cesario@tecnico.ulisboa.pt + Current address: Politecnico di Milano, Dipartimento di Chimica Materiali e Ingegneria Chimica "Giulio Natta". Via Mancinelli, 7 -20131 Milano MI 2 cyclohexanone and phenetole were used as extraction solvents and the relevant process variables (extraction temperature, extraction time and mass of cells/solvent volume ratio) were optimized.Polymer recovery yields of 97% and 93% were obtained with anisole and cyclohexanone, respectively, at 120-130°C using a cell/solvent ratio of 1.5% (w/v). Maximum polymer purities using these experimental conditions were 98% for both solvents. Recovery yields and polymer purity attained with chloroform (reference solvent) were 97 and 98%, respectively. Higher cell/solvent ratios of 6.0 % (w/v) showed slightly lower recovery yields and purities The average molecular weight and the thermal properties of the polymers extracted with the alternative solvents were comparable to those of the polymers obtained by chloroform extraction, showing that the applied conditions did not significantly alter the properties of the extracted P(3HB).

Hydrogels of mono‐n‐alkyl itaconate/N‐acrylamide have been synthesised. The swelling process at three different pH values (acid, neutral and basic) has been studied. The experimental data indicate that our hydrogels follow second‐order swelling kinetics. According to this, the kinetic constant, K∞, and the swelling capacity at equilibrium, W∞, have been calculated. The influence of the solvent pH and the molar mass of the mono‐n‐alkyl itaconate monomeric unit has been analysed. It seems that the general balance between the hydrogen bonding and the hydrophobic interactions regulates the swelling process of these hydrogels.

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Films of chitosan and chitosan-oligosaccharide neutralized and thermally treated: Effects on its antibacterial and other activities, LWT -Food Science and Technology (2016), doi: 10.1016/j.lwt.2016 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT ABSTRACT: 16The present study focuses on the effects of heat and neutralization treatments on 17 solubility, water vapour permeability and antimicrobial activity of chitosan (Ch) and 18 chitosan/chitooligosaccharide (ChO)-based films. ChO films showed stronger 19 antimicrobial activity against Escherichia coli, Bacillus cereus, Staphylococcus aureus, 20 Serratia liquefaciens and Lactobacillus plantarum than Ch films, indicating that this 21effect is attributed to the presence of chitooligosaccharides (COS) in the films. Heat 22 and neutralization treatments decreased significantly the solubility of chitosan films and 23 gave rise to a sharp loss in their antimicrobial activity. The incorporation of COS in 24 chitosan films increased the inhibitory effect against the studied microorganisms 25 without affecting significantly the water vapour permeability of the films. Thus, it is 26 possible to get a more insoluble chitosan film with high antimicrobial activity by means 27 of incorporation of COS combined with heat or neutralization treatments.