摘要:
The oligomer content in crude polydichlorophosphazene polymer is reduced to less than about 7% by a continuous process wherein the crude polymer in solution is introduced into an extruder along with solvent selective for the oligomer whereby polymer coagulates and liquid phase rich in oligomer is formed and is prevented from exit at the polymer discharge end of the extruder by the concentration and coagulation of the polymer and is separated from the concentrated polymer upstream of the polymer discharge end by mechanical filtering.
摘要:
Low or no chlorine content poly(aryloxyphosphazene) copolymers useful for fireproof foams are surprisingly produced in a one step process without use of excess phenoxide reactant over a shorter than conventional time period by (a) adding linear (NPCl 2 ) n to a mixture of phenoxides comprising alkali or alkaline earth metal phenoxide, alkylphenoxide and allylphenoxide in quantities such that the total of the phenoxides is the equivalent of the total chlorine atoms in the (NPCl 2 ) n and allylphenoxide is present in an amount equivalent to from about 2% to about 10% of the chlorine atoms in the (NPCl 2 ) n ; and (b) reacting the admixture formed in step (a) at a temperature ranging from about 280°F. to about 320°F. for a time period ranging from about 7 hours to about 10 hours.
摘要:
The oligomer content in crude polydichlorophosphazene polymer is reduced to less than about 7% by a continuous process wherein the crude polymer in solution is introduced into an extruder along with solvent selective for the oligomer whereby polymer coagulates and liquid phase rich in oligomer is formed and is prevented from exit at the polymer discharge end of the extruder by the concentration and coagulation of the polymer and is separated from the concentrated polymer upstream of the polymer discharge end by mechanical filtering.