摘要:
The present invention relates to a method for performing a polymerization process in a stirred reactor, wherein a critical time window is determined by means of a monitor of at least one polymerization process parameter and an associated process window, and when a critical time window is present, an adaptation of process conditions is made in order to configure the polymerization process to conform to the process window.
摘要:
The present invention relates to a process for the preparation of polysulfones having a yellowness index according to DIN 6167 of less than 19 and polyether sulfones having a yellowness index according to DIN 6167 of less than 30, wherein the polymerization is carried out in basic, aprotic solvents with the use of a positively conveying stirrer passing close to the wall. The present invention also relates to the polyether sulfones and polysulfones obtainable for the first time by this process and to the use of such polymers for the production of moldings, films, membranes and foams.
摘要:
The present invention relates to a method for performing a polymerization process in a stirred reactor, wherein a critical time window is determined by means of a monitor of at least one polymerization process parameter and an associated process window, and when a critical time window is present, an adaptation of process conditions is made in order to configure the polymerization process to conform to the process window.
摘要:
The invention relates to expandable styrene polymers for elastic polystyrene foams, comprisinga) from 75 to 98% by weight of polystyrene and/or a styrene copolymer containing at least 50% by weight of copolymerized styrene,b) from 2 to 25% by weight of at least one styrene-soluble elastomer,c) from 1 to 15% by weight, based on the sum of a) and b), of a low-boiling blowing agent, and, if desired,d) conventional additives in effective amounts,where the unfoamed beads have a structure in which the elastomer phase is dispersed in the polystyrene phase in the form of cell particles, and to foams and foam moldings produced therefrom.
摘要:
Provided is a method for performing a polymerization process in a stirred reactor, wherein a critical time window is determined by means of a monitor of at least one polymerization process parameter and an associated process window, and when a critical time window is present, an adaptation of process conditions is made in order to configure the polymerization process to conform to the process window.
摘要:
An expandable styrene polymer comprisinga) from 0 to 90% by weight of a styrene polymer or styrene copolymer other than b) contains at least 50% by weight of copolymerized styrene,b) from 10 to 100% by weight of a styrene/methacrylamide copolymer comprising from 0.5 to 50% by weight of at least one copolymerized N-substituted methacrylamide of the formula I ##STR1## where R.sup.1 and R.sup.2 are identical or different and are hydrogen, C.sub.1 - to C.sub.15 -alkyl, C.sub.6 - to C.sub.16 -cycloalkyl or C.sub.6 - to C.sub.20 -aryl, it being possible, if R.sup.1 and R.sup.2 contain at least 2 carbon atoms, for at least 2 carbon atoms to be linked via hetero atoms, andc) from 1 to 15% by weight, based on the sum of a) and b), of an aliphatic C.sub.3 - to C.sub.9 -hydrocarbon and/or carbon dioxide as blowing agent.
摘要:
The invention relates to expandable styrene polymers for elastic polystyrene foams, comprisinga) from 50 to 75% by weight of polystyrene and/or a styrene copolymer containing at least 50% by weight of copolymerized styrene,b) from 5 to 30% by weight of a styrene-soluble elastomer,c) from 5 to 20% by weight of at least one block copolymer containing styrene as one component,d) from 15 to 50% by weight of at least one polyolefin,e) from 1 to 15% by weight, based on the sum of a) and b), of a low-boiling blowing agent, and, if desired,f) conventional additives in effective amounts,and to foams produced therefrom.