Design and characterisation of novel blends of poly(lactic acid)

This thesis is concerned with the effect of polymer structure on miscibility of the three component blends based on poly(lactic acid) (PLA) with using blending techniques. The examination of novel PLA homologues (pre-synthesised poly(a-esters)), including a range of aliphatic and aromatic poly(a-esters) is an important aspect of the work. Because of their structural simplicity and similarity to PLA, they provide an ideal system to study the effect of polyester structures on the miscibility of PLA polymer blends. The miscibility behaviour of the PLA homologues is compared with other aliphatic polyesters (e.g. poly(e-caprolactone) (PCL), poly(hydroxybutyrate hydroxyvalerate) (P(HB-HV)), together with a series of cellulose-based polymers (e.g. cellulose acetate butyrate (CAB)). The work started with the exploration the technique used for preliminary observation of the miscibility of blends referred to as “a rapid screening method” and then the miscibility of binary blends was observed and characterised by percent transmittance together with the Coleman and Painter miscibility approach. However, it was observed that symmetrical structures (e.g. a1(dimethyl), a2(diethyl)) promote the well-packing which restrict their chains from intermingling into poly(L-lactide) (PLLA) chains and leads the blends to be immiscible, whereas, asymmetrical structures (e.g. a4(cyclohexyl)) behave to the contrary. a6(chloromethyl-methyl) should interact well with PLLA because of the polar group of chloride to form interactions, but it does not. It is difficult to disrupt the helical structure of PLLA. PLA were immiscible with PCL, P(HB-HV), or compatibiliser (e.g. G40, LLA-co-PCL), but miscible with CAB which is a hydrogen-bonded polymer. However, these binary blends provided a useful indication for the exploration the novel three component blends. In summary, the miscibility of the three-component blends are miscible even if only two polymers are miscible. This is the benefit for doing the three components blend in this thesis, which is not an attempt to produce a theoretical explanation for the miscibility of three components blend system.

Territory and party:explaining public policy variation in the German Länder

This paper discusses in way in which partisan influence upon public policy, and wider historical, political and institutional pressures, can operate on a regional level and can lead to divergent policies existing within a nation-state. It offers an empirical discussion of two policy areas (education and childcare) at the regional Level (the level of the Länder) in Germany, confirming that both the partisan composition of regional government, and also wider institutional and historical pressures, exert a clear influence upon policy, lead to sharply variations in policy within the nation state. Two conclusions can be drawn: that the region cab be an important unit of analysis in Political Science and Public Policy, and that scholars of policy change may find the regional level fertile ground in analysing wider political phenomena.

Novel three-component blends based on poly(L-lactide)

A significant number of poly a-ester homologues of poly(L-lactide) (PLLA) have been synthesized and used in miscibility studies together with conventional isomeric diacid-diol polyester variants, poly ß-esters (based on ß-hydroxybutyrate (HB) and ß-hydroxyvalerate (HV)), poly e-caprolactone (PCL), poly e-caprolactone copolymers (e.g. poly(L-lactide-co-caprolactone), and a series of cellulose-based polymers (e.g. cellulose acetate butyrate (CAB), cellulose acetate propionate (CAP)). A combinatorial approach to rapid miscibility screening using 96-well plates and a uv-visible multi-wavelength plate reader has been developed enabling the clarity of PLLA-based multi-component blend films to be observed. Using these techniques and materials, the ternary phase compatibility diagrams of a range of three-component blend films was prepared, illustrating ranges of behavior varying from miscible blends giving rise to clear films to immiscible blends which are opaque. In this way, novel three-component blends of PLLA/CAB/PCL were developed which are miscible when the CAB content is more than 30%, PLLA less than 80% and PCL less than 60%.

Basisdiskothek Rock und Pop:Essential collection rock and pop

Was darf in einem gutsortierten Plattenschrank aus den Bereichen Rock und Pop nicht fehlen? Uwe Schütte beantwortet diese drängende Frage. Inzwischen hat er seine erfolgreiche Empfehlungsliste überarbeitet und den Band um fünf Klassiker sowie Entdeckungen in neuen Einzelartikeln ergänzt: von Abba über Burial, Death Cab For Cutie und Tocotronic bis hin zu Wilco. Register der Platten und Gruppen erleichtern die Orientierung in diesem für den Musikfan unentbehrlichen Band. What may be missing in a well-stocked record collection from the fields of rock and pop not? Uwe Schütte answers this pressing question. Since then he has revised his successful referral list and the band around five classics and new discoveries, supplemented in individual articles: Abba on Burial, Death Cab For Cutie and Plumb to Wilco. Register of the panels and groups to facilitate the orientation in this indispensable volume for the music lover.