SynopsisInvestigations were undertaken of the structure and rheological properties of mixtures consisting of one crystallizing and one amorphous polymers. It was established that mixtures of poly(ethylene adipate) and poly(vinyl acetate); of poly(ethylene adipate) and poly(methyl methacrylate); and of poly(ethylene sebacinate) and poly(methyl methacrylate) can form amorphous solid solutions with one another or can crystallize without any apparent division of the two components. The phase condition of the mixture is determined by the nature of the two polymers, by the ratio between them, and by their molecular weights. The melting point of these mixtures drops in proportion to the content of the amorphous component. The assumption is made on the basis of the results obtained that the amorphous component occupies the defective areas in the crystal grating. The fluidity of the mixtures was measured by means of a capillary viscosimeter. I t was established in all cases that there appear deviations from the proportional change of the effective viscosity between the viscosities of the components. These deviations are explained by the change in the energy of activation of the viscous flow of the melts which was also subject to determination.In recent years there has been a steadily growing interest in polymer mixtures. This interest is due to the fact that there is no simpler, more accessible, and sometimes more effective way of modifying the properties of polymers than by mixing two or more of them. The properties of the mixture change slowly within certain limits, depending on the composition of the solid dispersion system. Sometimes, however, the mixtures reveal properties which none of the components possesses. The wide application of polymer mixtures has been achieved so far along practical lines. It is still not known what connection there is among the properties, structure, and composition of the mixtures. Furthermore, an investigation of polymer mixtures should permit us to broaden and supplement the data we have on individual polymers. They are highly convenient models for the purpose.Of greatest interest are the systems composed of amorphous and crystallizing polymers. These are characterized by two opposing trends: the crystal formation of the crystallizing components, on the one hand, and the formation of an amorphous solution between the components, on the 4197

ZUSAMMENFASSUNGDie rheologischen Eigenschaften von mit unterschiedlichen Mengen Holzmehl gefulltem Polypropylen, von mit 1 ,4-cis-Polyisoprena elastifiziertem Polypropylen und von ternaren Blends aus Polypropylen, Polyisopren und Holzmehl wurden untersucht. Die FlieBkurven der Schmelzen wurden rnit einem Kapillarviskosimeter erhalten, und daraus wurden der FlieBindex, der Konsistenzkoeffizient und die Stromungsgeschwindigkeit durch die Kapillare bestimmt. Die Schmelzen zeigen einen pseudoplastischen Stromungscharakter, wobei am leichtesten die Blends rnit 7 bis 15 Gew.-% Elastomeranteil stromen. Aus der ScherviskositPt wurde rnit der Gleichung von FrenkelEyring die Aktivierungsenergie der viskosen Strdmung berechnet. Das elastifizierte Polypropylen zeigt eine erhdhte Schlagfestigkeit, ein holzartiges Aussehen und eine grol3ere Wetterbestandigkeit als das rnit Holzmehl gefullte Polypropylen ohne Elastomeranteil. SUMMARY:The rheological properties of polypropene containing various amounts of woodflour, of polypropene elastified with 1 ,4-poly-cis-isoprene and of the ternary composite material based on polypropene, elastified polypropene and wood-flour were studied. The flow curves (viscosity curves) of the melts were obtained by means of a capillary viscosimeter, and the melt flow index, the consistency index and the melt flow rate through the capillary were determined from these curves. A pseudo-plastic nature of the flow was established, the compositions containing 7 to 15 wt.-% of elastomer

A study has been made of an unsaturated polyester resin prepared from maleic anhydride, phthalic anhydride and 1,a-propene glycol. The resin is transformed by alkalization with ammonia into a water-soluble emulsion, which was polymerized with initiators and accelerators. It was found that water acts as an inert diluent in the emulsion. By measuring the temperature of the reaction mass during polymerization, the actual conversion has been estimated. The latter is lower than literature values. A correction of the method of A. Rojas et a1 for the determination of the actual conversion is proposed, and the polymerization heat is thus determined. A value of 478 J/g is obtained, which is higher than reported. The apparent order of the polymerization reaction has also been determined: it changes from 5 to 18 with reaction progress.

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