摘要:
The heat distortion resistance and the molecular weight of polypropylene terephthalate and polybentylene terephthalate can be increased by cocondensing up to 10 mol-% of aliphatic diols containing 5 to 10 carbon atoms or of cycloaliphatic diols containing 8 to 12 carbon atoms.
摘要:
The present invention relates to an improved continuous process for the preparation of polyurethane elastomers which are distinguished from the products produced by known processes by increased elasticity, reduced shrinkage, higher rigidity (limit bending stress), improved cold notched bar impact resistance and good thermal stability.
摘要:
Composite materials are formed by subjecting a highly elastic material to a plasma treatment and then allowing a polyurethane foam forming mixture to foam on the plasma treated surface. These composites are particularly useful as shoe soles and as insulating materials.
摘要:
A homopolymer or copolymer which contains, as a monomer unit, at least one styrene of the formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 independently of one another denote hydrogen, fluorine or partly or completely fluorinated alkyl or alkoxy andR.sup.4 and R.sup.5 independently of one another represent hydrogen or fluoride, the total number of fluorine atoms in the radicals R.sup.1 to R.sup.5 being at least 3 and the total number of carbon atoms in the radicals R.sup.1 to R.sup.3 being at most 8. The homo- or copolymers can be prepared by vinyl polymerization. They are useful as lenses or other components in an optical system where they have a refractive index n.sub.D of 1.42 to 1.55 with an Abbe number v.sub.D of 30 to 50.
摘要:
Thermoplastic aromatic polyesters comprising cocondensed bisphenol residues generally have a refractive index n.sub.d of from 1.60 to 1.66, an Abbe coefficient v.sub.d of from 27 to 21 and a color triplet of about 5.1, 0.1, O and are excellent starting materials for the production of optical components, particularly high quality lenses for still and cine cameras.