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Reactive blending is the preferred route for obtaining rubber-toughened engineering plastics. In this study the chemistry and morphology of in-situ compatibilised PA-6/EPM-g-MA blends and PBT/E-MA-GMA blends are compared. Despite the different chemical structures formed (PA-6: cyclic imide; PBT: ester), the different side-reactions that take place (PA-6: chain scission; PBT: rubber crosslinking) and the different reaction rates (PA-6: very fast; PBT: rather slow), a general description of reactive blending is proposed. First, a very fast physics-controlled dispersion of the rubber phase into the polycondensate matrix occurs (from milimeter to micrometer scale). Then the interface, thus generated, is covered via graft-copolymer formation. This results in a stabilisation against coalescence and in a reduction of the interfacial tension, enabling further dispersion of the rubber phase. In the case of PA-6/EPM-g-MA blends the graft formation occurs so quickly that when the physics-controlled dispersion is completed, the final dispersion is achieved. In the case of PBT/E-MA-GMA blends the graft formation is much slower and the chemistry-controlled dispersion can hence be considered as a secondary process, yielding the final morphology.

A series of aromatic liquid-crystalline polyesters with different composition have been synthesized to adjust transition temperatures and molecular weight. Miscibility of polyesters with bisphenol-A-diglycidyl ether (DEGBA), 4,4'-methylene-bis(3-chloro-2,6-dimethylaniline) (MCDEA) and the influence on transition temperatures has been studied. Miscibility of binary and ternary mixtures was found over the whole range of composition depending on the temperature. Thermoset formation by curing of LC-polyester / DEGBA / MCDEA mixtures containing different amounts of polyester resulted in reaction-induced phase separation with polyester content from 30 to 50 wt.%. Cloud point techniques, scanning electron microscopy (SEM) and dynamic mechanical thermal analysis (DMTA) have been applied.

The fractionation of a statistical copolyester made of poly(ethylene terephthalate- isophthalate) has been performed using Temperature Rising Elution Fractionation (TREF). TREF fractions were analyzed by size exclusion chromatography, thermal analysis, H-1-nuclear magnetic resonance and small angle X-Ray diffractometry. Results show that the fractions exhibit both interchain and intrachain defect distribution. As the intrachain defect distribution can not be determined by experimental techniques, a computer simulation based on the determination of terephthalic sequences length in a virtual polymeric distribution was performed. The simulated chains were constructed using a stochastic process. The analysis of the results obtained on the distribution of the simulated sequences in the polymer correlates quantitatively well between the new fractionation mechanism proposed for copolyesters and the experimental results.

Thin polymeric films are assembled by the alternating adsorption of oppositely charged polyelectrolytes. The polyions are functionalized by azobenzenes, typically carrying donor-acceptor substituents. The azobenzene chromophores are exploited as versatile analytical tools, to study the assembling process, and to control the film quality. A high concentration of ionic groups does not seem to be advantageous per se for good film growth, but rather the matching of the charge densities of the polyelectrolyte pair used seems to be important. Also, the influence of the strongly interacting, form-anisotropic character of the azobenzenes on the internal film structure was investigated. Although even high concentrations of azobenzenes and of other mesogens do not induce particular ordering, a few polymer pairs allowed the construction of real multilayer films, exhibiting e.g. Bragg peaks.

The effect of the chemical and morphological modifications of the surface of poly(hydroxybutyrate-hydroxyvalerate) (92/8) (PHB/HV) films induced by an alkaline hydrolysis on the adsorption of three proteins known to modify cell behavior, namely albumin, collagen and fibronectin and on the adhesion and proliferation of monocytes-macrophages of the J774 cell line, has been studied. Before treatment, the water contact angle theta of the face that went through a corona pretreatment was higher than the other one. It increases with hydrolysis to equal the value of theta angle of the other face after 2 hours. The XPS analysis revealed that all the impurities present on the native material have been eliminated after hydrolysis leading to a similar chemical composition on both faces. The surface concentrations of -COOH functions accessible to [H-3]-lysine increases sharply with the duration of hydrolysis. The sharpest increase is observed at the very beginning of hydrolysis. The surface morphology of the polymer is also modified by hydrolysis. The adsorption of the three proteins increases when the polymer is hydrolyzed as well as the adhesion and proliferation of the monocytes-macrophages, no matter which protein was adsorbed. There are some evidence suggesting that the protein conformation is different on both substrates. Collagen has a drastic repulsive effect on the cells on the native polymer but this repulsive effect disappeared on the hydrolysed one. Accordingly, it clearly appears that it is possible to modulate the biocompatibility of PHB/HV by either chemical hydrolysis or protein adsorption.