Biodegradable Polylactide‐Based Composites

The aim of this chapter is to introduce to the use and possible applications of polylactide‐based composites. Polylactides are biodegradable aliphatic polyesters, which are widely used in medical and ecological‐friendly fields. First of all, a deep description of main characteristics of polylactides is shown. This chapter summarizes many concepts, which comprehend a general view of polylactide biopolymers such as synthesis and structures, physical‐chemical and mechanical characterization and possible applications of final products. Then, an overview of composites based on polylactides and their benefits compared with bare polylactides are described

The conformation of chloramphenicol in the ordered and disordered phases

The conformational behavior of chloramphenicol (CHL) in the solid, liquid and vapor phases is revisited here by means of FTIR spectroscopy and QM methods. In the crystalline phase, both the IR analysis and QM computations discard the conformer proposed by Acharya et al. (Acta Cryst., 1979, B35:1360–1363) and support the one proposed by Chatterjee et al. (J. Cryst. Mol. Struct., 1979, 9:295–304), characterized by an intramolecular O–H⋯O hydrogen bond in which the primary hydroxyl group acts as hydrogen bond donor. The conformational behavior of CHL in the liquid and gas phases has been analyzed using QM calculations. The Self-Consistent Reaction Field (SCRF) method with the Onsager solvation model has been used for the initial optimizations in solution, and the lowest energy conformers have been refined using the Solvation Model based on Density (SMD). In solution environment the intramolecular O–H⋯O hydrogen bond in CHL is reversed so that the secondary hydroxyl group acts as hydrogen bond donor. In addition, the dichloroacetamide group folds back further over the phenyl ring to form an intramolecular C–Cl⋯π halogen bond. Two different halogen bonds are actually observed (each one with a different chlorine atom) resulting in two different stable conformers, that can be detected by FTIR spectroscopy due to the conformational sensitivity of the C[dbnd]O group to the conformation of the dichloroacetyl group. Finally, the stability of the conformers with the polarity of the medium is also discussed.The authors are thankful for funds from the Spanish Ministry of In-novation and Competitiveness MINECO (MAT2016-78527-P), theBasque Government, Department of Education (IT-927-16) and the EUiPROMEDAI COST Action TD1305

Síntesis de mono y diitaconatos de alquilo y arilo

Se presenta una técnica para la síntesis en laboratorio de mono y diitaconatos y la separación de los mismos por extracción selectiva con solventes orgánicos. La pureza de los productos se determina por cromatografía en capa fina y por espectroscopia infrarroja

Síntesis de mono y diitaconatos de alquilo y arilo

Se presenta una técnica para la síntesis en laboratorio de mono y diitaconatos y la separación de los mismos por extracción selectiva con solventes orgánicos. La pureza de los productos se determina por cromatografía en capa fina y por espectroscopia infrarroja

Novel Hydrogels of Chitosan and Poly(vinyl alcohol) Reinforced with Inorganic Particles of Bioactive Glass

Chitosan (CS) and poly(vinyl alcohol) (PVA) hydrogels, a polymeric system that shows a broad potential in biomedical applications, were developed. Despite the advantages they present, their mechanical properties are insufficient to support the loads that appear on the body. Thus, it was proposed to reinforce these gels with inorganic glass particles (BG) in order to improve mechanical properties and bioactivity and to see how this reinforcement affects levofloxacin drug release kinetics. Scanning electron microscopy (SEM), X-ray diffraction (XRD), swelling tests, rheology and drug release studies characterized the resulting hydrogels. The experimental results verified the bioactivity of these gels, showed an improvement of the mechanical properties and proved that the added bioactive glass does affect the release kinetics.Funds from the Spanish Ministry of Innovation and Competitiveness MINECO (MAT2016- 78527-P) and the Basque Government Department of Education, Language Policy and Culture (IT-927-16) are gratefully acknowledged.Peer reviewe

Predicting miscibility in polymer blends using the Bagley plot: Blends with poly(ethylene oxide)

This paper explores the different methods currently available to obtain the partial solubility parameters of polymers in order to apply them for the prediction of miscibility in polymer/polymer blends. Blends based on poly(ethylene oxide) (PEO) have been chosen because its miscibility has been reported with a large number of polymeric counterparts (miscible or not), allowing the representation of its miscibility map with the required detail. The solubility parameters of PEO and 55 blending partners have been obtained using the most widely used group contribution (GC) methods, namely the ones proposed by Hoy, Hoftyzer-Van Krevelen, Stefanis-Panayiotou and Yamamoto (Y-MB), and have been used to build a Bagley plot. In addition, the miscibility map based on experimental data obtained from solubility tests has been also obtained and compared with the calculated ones. The clouds of points obtained around the point corresponding to PEO show different shapes, that can be used to obtain conclusions about the coherence and the accuracy of each of the different methods used to obtain the solubility parameters of polymers.The authors are thankful for funds from the Spanish Ministry of Innovation and Competitiveness MINECO (MAT2013-45559-P), the Basque Government, Department of Education, Universities and Research (GIC12/161-IT-632-13) and the European COST Action TD1305 - iPROMEDAI.Peer reviewe