Mechanical properties of polystyrene-ethylene-propylene copolymer blends

Some mechanical properties of blends of polystyrene (PS) and ethylene-propylene-rubber (EP) were derived from stress-strain and impact measurements. The strength and impact properties are improved by adding EP-g-PS graftcopolymer, prepared by reacting PS with EP, to the blends. It is assumed that the EP-g-PS graftcopolymer acts as an adhesive at the interface between the thermoplast and the rubber phases. The addition of the graftcopolymer reduces the dimensions of the dispersed rubber particles. High values of impact strength at reasonable values of tensile moduli could be reached by replacing EP for a smaller or larger part by EP-g-PS copolymer. These kinds of EP-modified PS blends had much higher impact values than those of comparable PS blends containing low density polyethylene (I dPE) and 1 dPE-g-PS graftcopoly mer or this graftcopolymer only. It seems attractive to ascribe these results to the noncrystallinity of the PE-g-PS as compared with the crystallinity of ldPE in ldPE and in ldPE-g-PS. However some caution seems recommendable as EP-modified PS fractures with microshear whereas, the PE-modified PS shows crazing

Synthesis and structure of [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl] methylphenyltin bromide : A novel triorganotin halide having a configurationally stable chiral tin center

Reaction of [2-(4, 4-dimethyl-2-oxazoline)-5-methylphenyl]copper with dimethyltin dibromide or methylphenyltin dibromide affords [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]dimethyltin bromide (1) and [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]methylphenyltin bromide (2), respectively. The crystal structure of 2 has been determined by X-ray diffraction methods. C{1}{9}H{2}{2}BrNOSn is monoclinic, space group P2{t}/a with a = 18.1258(9), b = 11.5704(11), c = 9.5315(6) @9, @b = 95.143(6)}o{ and Z = 4, final R = 0.038 for 2760 observed reflections. As a result of intramolecular coordination of the nitrogen atom of the oxazoline ring to the tin atom, the geometry about tin in 1 is trigonal bipyramidal. The carbon ligands are at the equatorial sites, while the more electronegative nitrogen and bromine atoms are at the axial positions. An }1{H NMR spectroscopic study showed that in solution the chiral tin center is configurationally stable up to 120}o{C )the highest temperature studied)

Synthesis and structure of [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl] methylphenyltin bromide : A novel triorganotin halide having a configurationally stable chiral tin center

Reaction of [2-(4, 4-dimethyl-2-oxazoline)-5-methylphenyl]copper with dimethyltin dibromide or methylphenyltin dibromide affords [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]dimethyltin bromide (1) and [2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl]methylphenyltin bromide (2), respectively. The crystal structure of 2 has been determined by X-ray diffraction methods. C{1}{9}H{2}{2}BrNOSn is monoclinic, space group P2{t}/a with a = 18.1258(9), b = 11.5704(11), c = 9.5315(6) @9, @b = 95.143(6)}o{ and Z = 4, final R = 0.038 for 2760 observed reflections. As a result of intramolecular coordination of the nitrogen atom of the oxazoline ring to the tin atom, the geometry about tin in 1 is trigonal bipyramidal. The carbon ligands are at the equatorial sites, while the more electronegative nitrogen and bromine atoms are at the axial positions. An }1{H NMR spectroscopic study showed that in solution the chiral tin center is configurationally stable up to 120}o{C )the highest temperature studied)

8-(Dimethylamino)naphthylcopper(I), a novel stable organocopper compound with unusual structural features. A study concerning its synthesis, structure (X-ray) and reactivity. Its synthesis, crystal structure (X-ray) and reactivity

The synthesis and isolation of a hydrocarbon- and ether-insoluble organocopper compound containing the rigid 8-(dimethylamino)naphthyl group is described. An X-ray determination of its structure revealed a tetranuclear copper aggregate, in which the Cu atoms are arranged in a parallelogram (Cu...Cu 2.407(2) and 2.430(2) @9) and are three-center, two-electron bridged by C(ipso) (Cu-C 2.025(6) @9 mean) of the naphthyl group. The amine ligands coordinate pairwise to opposite copper atoms. The copper aggregate thus contains two distinct types of Cu atoms, involving two nucleophilic two-coordinate and two electrophilic four-coordinate sites, pointing to a strong cuprate character. Reaction of the organocopper compound with several copper(I) salts resulted either in the formation of binaphthyl and dimethylaminonaphthalene or a stable mixed copper cluster, depending on the anion in the copper salt. With dimethyl acetylenedicarboxylate the copper compound, without added lithium or magnesium salts, gave the (syn) addition product 8-Me{2}NnaphthylC(CO{2}Me)=C(CO{2}Me)Cu. These reactions are discussed in relation to the structural features of the tetranuclear organocopper compound