摘要:
Mixtures of aromatic polycarbonates and aromatic polyester-carbonates having a specific polycarbonate/polyester-carbonate ratio and a defined ester content in the polyester-carbonates, at least one of the polycondensates containing C.sub.8 -C.sub.9 -alkylated phenyl end groups, possess a reduced tendency to stress cracking.
摘要:
This invention relates to optionally branched polyarylene sulphides and a process for the production thereof in a polar solvent, from 0.2 to 100 mole %, based on the aromatic dihalogen compounds, of an amino acid being added to the reaction mixture.
摘要:
This invention relates to a process for the production of high molecular weight, optionally branched polyarylene sulphides from alkali metal sulphides and halogenated aromatic compounds in the presence of from 0.5 to 100 mol %, based on the molar quantity of aromatic dihalogen compounds, of an ester or anhydride of a carboxylic acid.
摘要:
Thermotropic fully-aromatic polyesters which contain radicals of 3,4'- and/or 4,4'-dihydroxybenzophenone in addition to radicals of p-hydroxybenzoic acid, iso- and optionally terephthalic acid, hydroquinone and/or 4,4'-dihydroxydiphenyl, have good rigidity and toughness and yet are easily processible.
摘要:
The invention relates to a process for the preparation of aromatic polyester-carbonates wherein, in a first stage, aromatic oligo-esters or oligo-ester-carbonates having hydroxyl end groups are prepared from diaryl esters of aromatic dicarboxylic acids (or their starting materials) and diphenols and, optionally, a diaryl carbonate, by trans-esterification in the melt, and in a second stage these oligo-esters or oligo-ester-carbonates are condensed with phosgene by the phase boundary process to give the polyester-carbonate.
摘要:
Process for the preparation of pure aromatic dicarboxylic acid dichlorides which comprises reacting an aromatic dicarboxylic acid or an aromatic dicarboxylic acid mixture with phosgen in one stage and in the presence of an N--C.sub.1 --C.sub.6 -alkyl-pyrrolidine, -piperidine or -morpholine as a catalyst and optionally in a solvent or diluent.
摘要:
This disclosure relates to the processes for producing polycarbonates from specific crude bisphenols. The bisphenols are characterized in that immediately after their preparation they are subjected to (i) separation, of excess phenols and low-boiling substances, by means of an evaporator, and (ii) removal of monophenols by desorption.The invention also relates to high-molecular weight aromatic polycarbonates made of crude bisphenols and their use in a variety of applications.
摘要:
This development is concerned with aromatic thermoplastic polycarbonates with special chain terminators which give the polymers enhanced hydrolysis resistance and impact toughness. These chain terminators are alkyl substituted monohydroxy phenyls in which each phenyl is substituted by one alkyl group having 8 or 9 carbon atoms and about 47 to 89% of its hydrogen atoms trisubstituted on carbon atoms with up to about 20% of the substituents in the ortho position and the balance at the para position. This development is also concerned with a process for synthesizing such polymers by using such chain terminators as reactants in generically known synthesis methods for polycarbonates.
摘要:
Resins having a softening point of from 50.degree. to 130.degree. C., an OH-number of from 250 to 400 and an iodine number of from 90 to 160, obtainable by reacting an alkyl phenol-formaldehyde novolak or an alkyl phenol mixture-formaldehyde novolak under acid-catalysed conditions with a polunuclear phenol or polynuclear phenol mixture and formaldehyde and/or an aliphatic aldehyde or aliphatic aldehyde mixture, the ratio by weight of the alkyl phenol or alkyl phenol mixture to the polynuclear phenol or polynyclear phenol mixture being from 2.2:1 to 1:10.