This paper describes the Fourier-transform infrared (FTIR) spectroscopy of a series of polyanhydrides made of the following diacids: sebacic acid (SA); 1,3-bis@-carboxyphenoxy)propane (CPP); 1,6-bis@-carboxyphenoxy)hexane (CPH); (carboxyphenoxy)methane (CPM); fumaric acid (FA); 5-@-carboxyphenoxy)valeric acid (CPV). All the polymers revealed typical anhydride peaks corresponding to aliphatic-aliphatic, aliphaticaromatic, and aromaticaromatic diads in the wavenumber range 1820-1710 cm-l. Additional paired peaks corresponding to SA-SA diads were identified in the fingerprint region at 1382,1360 and 1307,1286 cm-I. The second pair was assigned to the crystalline regions of the copolymers. This information allows easy identification of bond distribution in a variety of polyanhydrides, and correlates well with information previously presented using nuclear magnetic resonance (NMR) spectroscopy and X-ray powder diffraction.

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ABSTRACT:The phenomenon of enthalpic relaxation was evaluated for poly(lactide-co-glycolide) (PLGA, 50:50), in terms of storage of nanospheres for use as a controlled drug delivery system. Samples were stored for different times and temperatures below the glass transition temperature (T g ). Relaxation occurred at a significant rate up to 15 degrees below the T g of 39.2°C. The effect of polymer morphology was considered by comparing the relaxation kinetics of the raw polymer with that of nanospheres formed using a novel technique. The nanospheres were shown to have a larger change in heat capacity at the glass transition and a longer average relaxation time than that of the raw polymer, and the relationship between these two parameters was discussed. For both the raw polymer and the nanospheres, relaxation was found to occur at a significant rate at room temperature. The storage of this system at subambient temperatures was therefore deemed important for maintaining the physicochemical properties of the system.

Security is a non-functional requirement difficult-to-handle during software development. However, it appears to be common in software engineering, that security is taken care of during the design- and test-phase only. If security is neglected during the implementation phase, flaws will be introduced. Those may be - if at all - found during testing where the cost-to-fix is higher as if found during the implementation phase. Hence, this research proposal suggests to investigate the extent to which code analysis tools can be used as a step towards continuous security inspection in software engineering projects. By automating security testing in development flaws can be found as soon as they are introduced. This could greatly reduce the cost to fix flaws and help building more secure software.