Mechanical Behaviour and Biocompatibility of Poly(1-Vinyl-2-Pyrrolidinone)-Gelatin IPN Hydrogels
Lopes CMA, Felisberti MI

24 (7): 1279-1284 MAR 2003


IPN hydrogels based on poly(1-vinyl-2-pyrrolidinone) and gelatin were obtained by casting of aqueous solution using potassium persulphate and glutaraldehyde as respective crosslinking agents. Studies of swelling and mechanical behaviour showed that the samples of different composition can incorporate high content of water and still exhibit high compression strength. The composition has influence at the global crosslinking density what affects the mechanical performance. In vitro biocompatibility and hemocompatibility were also investigated. The materials do not interfere on the cellular functions and neither induce platelet adhesion. From this preliminary evaluation, it is possible to conclude that these hydrogels have potential for applications in the biomedical field.



Blends of i-PP and SBS. II. Influence of in situ Compatibilization on the Mechanical Properties
Wilhelm HM, Felisberti MI

87 (3): 516-522 JAN 18 2003


This article concerns the in situ compatibilization of immiscible isotatic polypropylene/ styrene-butadiene-styrene triblock copolymer blends (i-PP/SBS) by use of a reactive mixture. For this purpose, maleated PP (PP-MAH) and SBS (SBS-MAH) were used as functionalized polymers and 4,4'-diaminediphenylmethane was used as a coupling agent between maleated polymers, resulting in a graft copolymer. Binary blends of i-PP/SBS, nonreactive ternary blends of i-PP/PP-MAH/SBS, and reactive ternary blends of i-PP/PP-MAH/SBS-MAH with varying diamine/anhydride molar ratios were prepared. The mechanical properties of the blends were determined by tensile and impact-resistance tests. The optimum improvement in the mechanical properties was found when the diamine/anhydride molar ratio in the ternary reactive blends was 0.5/1. (C) 2002 Wiley Periodicals, Inc.