Cellulose acetate phthalate (CAP)/hydroxypropyl cellulose (HPC) blends were investigated by means of attenuated total reflection‐Fourier transform infrared spectroscopy, thermogravimetry/differential thermal analysis, shear viscosity, oscillatory shear tests, and atomic force microscopy (AFM). Effect of solution concentrations in 2‐methoxyethanol, blend compositions, and shear rate on the rheological functions reflects the mobility of the chain segments or their orientation—with thinning behavior in the shear field. Specific interactions, such as the hydrogen bonds between polymer components and 2‐methoxyethanol used in casting solutions of films, influence the resulting morphology. Supernodular aggregates with different intensities and dimensions, which involve the coexistence of an isotropic and an anisotropic phase, typical for lyotropic cellulosic derivative liquid crystals at low concentrations, are evidenced by AFM images. This study is useful for applications of CAP/HPC blends in pharmaceutical domains.POLYM. COMPOS., 33:2072–2083, 2012. © 2012 Society of Plastics Engineers

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Surface wettability trends, and blood component adhesion of some cellulose acetate phthalate/hydroxypropyl cellulose blend films are analyzed in view of adapting the system to biomedical applications. The results show that intermediate blend compositions of the corresponding films influence the surface tension parameters-controlled by the interactions occurring in the system. Increasing hydrophobicity and, implicitly, decreasing the polar surface tension components, are correlated with the adhesion/cohesion of blood components and plasma proteins. Thus, the work of spreading proteins on the hydrophobic blend surfaces indicated that albumin is not absorbed preferentially, while fibrinogen is characterized by a higher degree of adhesion on the surfaces, and also that selective adsorption of plasma proteins modifies blood compatibility. In addition, the obtained results and the ascertained antimicrobial activity of the studied blends contribute to the development of new applications in the biomedical field.

The Canadian Highway Bridge Design Code (CHBDC) does not permit the use of glass-fibre-reinforced polymer (GFRP) for primary reinforcement or prestressing tendons in concrete components. The restriction on the use of GFRP in concrete was based on published laboratory studies indicating that GFRP is not stable in the alkaline environment of concrete. In 2004, ISIS Canada sponsored an extensive study of the durability of GFRP in concrete by removing cores from GFRP-reinforced concrete components of five 5-to 8-year-old structures from across Canada. Three teams working independently at several Canadian universities used a variety of analytical methods to (i) investigate whether the GFRP in concrete field structures had been attacked by alkalis and (ii) compare the composition of GFRP removed from in-service structures with the composition of control specimens that were saved from the projects and not exposed to the concrete environment. The analytical results have confirmed that the GFRP in concrete did not suffer any damage during the 5-8 years of exposure. As a result of this study, the CHBDC in its forthcoming (second) edition has permitted the use of GFRP for both primary reinforcement and prestressing tendons in concrete components, provided the maximum stress level in GFRP at the serviceability limit state is kept at or below 25% of its ultimate strength. It was also found that, contrary to some claims, concrete over GFRP bars does not crack even if the depth of cover is as thin as 28 mm. 366Key words: alkali attack, barrier wall, crack, deck slab, depth of cover, fibre-reinforced polymer (FRP), glass-fibrereinforced polymer (GFRP). (2000) ne permet pas l'utilisation de polymères renforcés de fibres de verre (« GFRP ») comme armature principale de renforcement ou de précontrainte dans les composantes en béton. La restriction de l'utilisation des « GFRP » dans le béton était basée sur des études en laboratoire publiées qui indiquaient que les « GFRP » n'étaient pas stables dans l'environnement alcalin du béton. En 2004, ISIS Canada a parrainé une étude détaillée sur la durabilité des « GFRP » dans le béton en prélevant des carottes de composantes en béton armé de « GFRP » de structures âgées de 5 à 8 ans de divers endroits au Canada. Trois équipes indépendantes dans plusieurs universités canadiennes ont utilisé diverses méthodes pour (i) examiner si les alcalis avaient attaqué ou non les « GFRP » dans les structures de béton sur le terrain et (ii) comparer la composition des « GFRP » prélevés des structures en utilisation par rapport aux échantillons de référence qui avaient été mis de côté lors des projets et non exposés au béton. Les résultats analytiques ont confirmé que les « GFRP » dans le béton n'ont subi aucun dommage durant les cinq à huit années d'exposition. Grâce aux résultats de la présente étude, le Code canadien sur le calcul des ponts routiers permettra, dans sa seconde édition à paraître bientôt, l'utilisation des « GFRP » comme armature de renforcement principale et de précontrainte dans les c...

The chapter overviews recent progress made in the area of cellulose acetate nanocomposites, considering their high-volume applications and easy processing ability. Based on their structural details, the review provides data concerning the manufacturing, characterization, and new developments in this area, with particular emphasis on biomedical applications. Stress is laid on the importance of antimicrobial activity, correlated with different bacteria characteristics, on also considering that their interaction mechanisms create inhibitory effects against microbial growth in a solid medium, and decide their areas of applicability. In this context, the presented aspects show that cellulosic materials can be designed and fine-tuned to acquire certain properties required in different biomedical areas.

The current paper presents a strategic way to design and develop materials with properties adapted for various applications from biomedicine to environmental applications. In this context, blends of (hydroxypropyl)methyl cellulose (HPMC) and poly(vinylpyrrolidone) (PVP) were obtained to create new materials that can modulate the membrane properties in various fields. Thus, to explore the possibility of using the HPMC/PVP system in practical applications, the solubility parameters in various solvents were initially evaluated using experimental and theoretical approaches. In this frame, the study is aimed at presenting the background and steps of preliminary studies to validate the blends behavior for targeted application before being designed. Subsequently, the analysis of the behavior in aqueous dilute solution of HPMC/PVP blend offers information about the conformational modifications and interactions manifested in system depending on the structural characteristics of polymers (hydrophilicity, flexibility), polymer mixtures composition, and used solvent. Given this background, based on experimental and theoretical studies, knowledge of hydrodynamic parameters and analysis of the optimal compositions of polymer mixtures are essential for establishing the behavior of obtained materials and validation for most suitable applications. Additionally, to guarantee the quality and functionality of these composite materials in the targeted applications, e.g., biomedical or environmental, the choice of a suitable solvent played an important role.