The synthesis of a series of vinylbenzyl ether macromonomers of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO–VBE) with number average molecular weights between 1,000 and 27,000 and narrow molecular weight distribution is presented. The reactivity ratio r1 was determined for the comonomer pairs methyl methacrylate (MMA) and butyl methacrylate (BMA), respectively (M1), and PPO–VBE (M2) over the entire range of molecular weights of the macromonomer. r1 was determined by the single experiment intergrated equation. Since both the monomer and macromonomer present an induction period, it has been shown that the determination of r1 from one single point experiment is not correct. Accurate r1 values can be obtained from one single copolymerization experiment only when the comonomer conversions are determined at several different reaction times. The macromonomer reactivity (1/r1) increases with its molecular weight up to about 5,000–7,000. Above these values its reactivity decreases. An attempt to explain this behavior based on the kinetic excluded free volume effect is presented.
Binary blends of poly(2,6-dimethyl-l,4-phenylene oxide) (PPE) with various styrene copolymers were investigated. Poly(styrene-co-acrylonitrile) ( S A N ) , poly[styrene-co-(methyl methacrylate)] (SMMA), poly[styrene-co-(acrylic acid)] (SAA) and poly[styrene-co-(maleic anhydride)] (SMA) are only miscible with PPE when the amount of comonomer is rather small. From calculated binary interaction densities it can be concluded that the strong repulsion between PPE and comonomer limits miscibility. In blends of PPE with SAN, as well as with ABS, the interfacial tension between the blend components is significantly reduced upon addition of polystyrene-block-poly-(methyl methacrylate) diblock copolymers (PS-b-PMMA) and polystyrene-block-poly(ethylene-co-butylene)-block-poly-(methyl methacrylate) triblock copolymers (PS-b-PEB-b-PMMA). They show a profound influence on morphology, phase adhesion and mechanical blend properties.
INTRODUmION
The structure of I-azabicyclo[4.2.0]octane (1) was evaluated by NMR spectroscopy. It was found that the six-membered ring has a chair conformation with the four membered ring in the N-axial and C-dequatorial position, and as a consequence, the monomer allows neither a ring inversion nor a nitrogen inversion. It possesses two centers of chirality, one at the nitrogen atom and one at C-6. Homopolymerization was carried out in methanol at 60°C with N-alkyl ammonium salts of 1 affording the polymer in high yield within a few hours. Its NMR spectra reveal that the polymer chain is preferably arranged in the biequatorial position of the sixmembered ring. As a polybase the polymer can be titrated quantitatively with acids. Its glass transition temperature is 8 "C, the decomposition starts at 320°C.
Synthesis and properties of cis‐and trans‐methoxyvinyl chloride (MVC) are described. magnified imageBoth of these monomers can be polymerized with cationic initiators. From the 13C‐NMR spectra it was concluded, that poly‐(trans‐MVC) is mainly threo‐diisotactic. Copolymerization of cis‐MVC with for instance trans‐MVC or styrene or 1,3‐dioxolane is also described.The ring‐opening polymerization of 2‐phenyl‐2‐oxazoline under different conditions was investigated. magnified imageThe molecular weights, determined by light‐scattering and GPC are in the range between 10 000 and 350 000. A[η] ‐M‐ equation was derived. By hydrolysis with hydrochlorid acid high molecular weight poly(iminoethylene) was obtained.The ring‐opening polymerization of 1‐azabicyclooctane [4.2.0] (conidine) with different catalysts as well as the properties of the polymers were studied in detail. magnified imageBy means of a “mixed‐mechanism technique” well defined styrene‐conidine diblock copolymers are available.
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