摘要:
Process for the preparation of copolyamides from adipic acid, terephthalic acid and hexamethylene diamine containing 25-48% by weight of units of hexamethylene terephthalamide, by precondensing the monomers at a temperature of at least 250.degree. C. and a pressure of at least 35 bar and completing the polycondensation in the usual manner.
摘要:
Low-molecular polyesters prepared by the condensation of diols and dicarboxylic acid dialkyl esters show a substantially improved capactiy to undergo polycondensation in a susequent polycondensation below the melting point if said low-molecular polyesters are prepared from pressure trans-esterification products by polycondensation in the melt.
摘要:
Block copolyesters based on polyalkylene terephthalates which contain polyene blocks show an extremely low deformation even when they are processed into thin articles. They still have a crystallinity which is decreased by less than the ratio corresponding to the polyene portion.
摘要:
Process for the preparation of polyamides from 1,4-diaminobutane and adipic acid, wherein a 40 to 70% strength aqueous solution of the monomers is heated at 280.degree.-320.degree. C., preferably 290.degree.-310.degree. C., for a period of 5 to 30 minutes under a pressure of less than 8 bar, to give a precondensate having a relative viscosity of 1.05 to 2.0, and solid phase after-condensation at 180.degree.-260.degree. C.
摘要:
A process for the production of copolyamides from aromatic dicarboxylic acids, adipic acid, and hexamethylene diamine having from 30 to 51.5% by weight of units of the hexamethylene adipic acid amide, the monomers being precondensed at at least 250.degree. C. and under a pressure of at least 35 bars and the polycondensation being conducted in a conventional manner to completion.
摘要:
Block copolyesters based on polyalkylene terephthalates which contain polydiene blocks show an extremely low deformation even when they are processed into thin articles. They still have a crystallinity which is decreased by less than the ratio corresponding to the polydiene portion.
摘要:
A block copolymer is produced fromI. 1 to 60% by weight of at least one telechelic diene polymer containing terminal carbonate ester, --OH--, --NH.sub.2 --, carboxylic acid or carboxylic acid ester groups and having a molecular weight M.sub.n of from about 400 to 1300, andII. 99 to 40% by weight of at least one polyamide or polyamide-forming component.
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:
Trialkylsilyloxy-1,1-diphenyl ethylenes corresponding to general formula I, new polymers produced therewith terminated by aryl trialkylsilyl ether groups or by phenolic hydroxyl groups and a process for the production of these polymers by anionic polymerization ##STR1## in which R.sup.1, R.sup.2 .dbd.H, C.sub.1 -C.sub.4 alkyl, OCH.sub.3,R.sup.3 .dbd.H, C.sub.1 -C.sub.4 alkyl, O--C.sub.1 -C.sub.4 alkyl,R.sup.4 .dbd.H, C.sub.1 -C.sub.4 alkyl,R.sup.5 .dbd.C.sub.1 -C.sub.4 alkyl,R.sup.6 .dbd.H, C.sub.1 -C.sub.4 alkyl.