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Bonding Capacity (bonding + capacity)
Selected AbstractsPorous Structures: In situ Porous Structures: A Unique Polymer Erosion Mechanism in Biodegradable Dipeptide-Based Polyphosphazene and Polyester Blends Producing Matrices for Regenerative Engineering (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Mater. Abstract Synthetic biodegradable polymers serve as temporary substrates that accommodate cell infiltration and tissue in-growth in regenerative medicine. To allow tissue in-growth and nutrient transport, traditional three-dimensional (3D) scaffolds must be prefabricated with an interconnected porous structure. Here we demonstrated for the first time a unique polymer erosion process through which polymer matrices evolve from a solid coherent film to an assemblage of microspheres with an interconnected 3D porous structure. This polymer system was developed on the highly versatile platform of polyphosphazene-polyester blends. Co-substituting a polyphosphazene backbone with both hydrophilic glycylglycine dipeptide and hydrophobic 4-phenylphenoxy group generated a polymer with strong hydrogen bonding capacity. Rapid hydrolysis of the polyester component permitted the formation of 3D void space filled with self-assembled polyphosphazene spheres. Characterization of such self-assembled porous structures revealed macropores (10,100 ,m) between spheres as well as micro- and nanopores on the sphere surface. A similar degradation pattern was confirmed in vivo using a rat subcutaneous implantation model. 12 weeks of implantation resulted in an interconnected porous structure with 82,87% porosity. Cell infiltration and collagen tissue in-growth between microspheres observed by histology confirmed the formation of an in situ 3D interconnected porous structure. It was determined that the in situ porous structure resulted from unique hydrogen bonding in the blend promoting a three-stage degradation mechanism. The robust tissue in-growth of this dynamic pore forming scaffold attests to the utility of this system as a new strategy in regenerative medicine for developing solid matrices that balance degradation with tissue formation. [source] In situ Porous Structures: A Unique Polymer Erosion Mechanism in Biodegradable Dipeptide-Based Polyphosphazene and Polyester Blends Producing Matrices for Regenerative EngineeringADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Meng Deng Abstract Synthetic biodegradable polymers serve as temporary substrates that accommodate cell infiltration and tissue in-growth in regenerative medicine. To allow tissue in-growth and nutrient transport, traditional three-dimensional (3D) scaffolds must be prefabricated with an interconnected porous structure. Here a unique polymer erosion process through which polymer matrices evolve from a solid coherent film to an assemblage of microspheres with an interconnected 3D porous structure is demonstrated for the first time. This polymer system is developed on the highly versatile platform of polyphosphazene-polyester blends. Co-substituting a polyphosphazene backbone with both hydrophilic glycylglycine dipeptide and hydrophobic 4-phenylphenoxy group generates a polymer with strong hydrogen bonding capacity. Rapid hydrolysis of the polyester component permits the formation of 3D void space filled with self-assembled polyphosphazene spheres. Characterization of such self-assembled porous structures reveals macropores (10,100 ,m) between spheres as well as micro- and nanopores on the sphere surface. A similar degradation pattern is confirmed In vivo using a rat subcutaneous implantation model. 12 weeks of implantation results in an interconnected porous structure with 82,87% porosity. Cell infiltration and collagen tissue in-growth between microspheres observed by histology confirms the formation of an in situ 3D interconnected porous structure. It is determined that the in situ porous structure results from unique hydrogen bonding in the blend promoting a three-stage degradation mechanism. The robust tissue in-growth of this dynamic pore forming scaffold attests to the utility of this system as a new strategy in regenerative medicine for developing solid matrices that balance degradation with tissue formation. [source] Studies on synthesis and characterization of a novel acrylic aromatic amide oligomer of aminolysed endproducts generated from pet waste with hydrazine monohydrate and its photocuring with acrylate monomersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2010R. K. Soni Abstract A novel acrylic aromatic amide oligomer was synthesized by using depolymerized end product of PET waste with hydrazine monohydrate. The end product of aminolysed PET waste was synthesized under ambient conditions and was used in the preparation of novel acrylic oligomer with the reaction of acryloyl chloride prepared from acrylic acid. The acrylic oligomer was characterized by spectroscopic techniques, such as FTIR, 1H-NMR, UV, Mass spectrometry, and by other analytical techniques such as, Iodine value, TGA, and DSC. The proposed structure of the oligomer is supported by its spectral analysis and the same is inferred from other techniques. The acrylic oligomer mixed with other acrylate monomers such as methylmethacrylate, ethylhexylacrylate, acrylic acid, and photoinitiator, can be cured by UV radiation and can thus be used as an adhesion promoter on metal/glass surface. This article presents the possibility of using a difunctional aromatic amide oligomer with excellent hydrogen bonding capacity as an alternative to urethane acrylates in radiation curable formulations. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] The effects of surface lactone hydrolysis and temperature on the specific and nonspecific interactions between phenobarbital and activated carbon surfacesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2006Dale Eric Wurster Abstract The effect of hydrolyzing lactone functional groups on the surfaces of different activated carbons upon the specific and nonspecific interactions between phenobarbital and activated carbon surfaces was studied. The effect of temperature on both specific and nonspecific interactions was also studied. The increase in OH groups on the surfaces of activated carbons, as a result of hydrolyzing surface lactone groups, caused an increase in the specific adsorption capacity (K2) for phenobarbital without having a significant effect on the hydrophobic bonding capacity (KHB). Increasing the temperature at which the adsorption experiment was carried out, on the other hand, resulted in a decrease in KHB without having a significant effect on K2. The decrease in KHB per unit temperature increase was the same regardless of the activated carbon. These results are in very good agreement with the modified-Langmuir-like equation (M-LLE). © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95: 1540,1548, 2006 [source] | ||||||||||