Phosphorus-containing cellulose esters, methods for their preparation, their use, and flame retardants

A cellulose derivative of the general Formula I

• wherein
• R is the same or different on each occurrence and is selected from the group consisting of hydroxyl groups, moieties of the general formula II, and moieties of the general formula III
• wherein R1 is identical or different on each occurrence and is of the formula IV:
• wherein R3, R4, R5, and n are the same or different at each occurrence,
• R3 is selected from the group consisting of hydrogen or linear or branched alkyl moieties having 1 to 36 carbon atoms, and
• R4 and R5 are independently selected from the group consisting of alkyl moieties, aryl moieties, alkyl aryl moieties, arylalkyl moieties, O-alkyl moieties, O-aryl moieties, O-alkyl aryl moieties, N-alkyl moieties, N-aryl moieties, N-arylalkyl moieties, and N-alkyl aryl moieties, wherein R4 and R5 and the phosphorus atom can also be part of heterocyclic ring systems, which can be single or multi-membered, and wherein the heterocyclic ring system is selected from the group consisting of the following moieties:
• wherein
• R6 is independently selected from the group consisting of alkyl moieties, aryl moieties, alkyl aryl moieties, arylalkyl moieties, O-alkyl moieties, O-aryl moieties, O-alkyl aryl moieties, N-alkyl moieties, N-aryl moieties, N-arylalkyl moieties, and N-alkyl aryl moieties;
• and
• n is 0 or an integer from 1 to 3, and
• R2 is identical or different on each occurrence and is selected from the group consisting of linear or branched alkyl moieties having 1 to 36 carbon atoms and linear or branched arylalkyl moieties having 7 to 36 carbon atoms,
• with the proviso that in formula I, at least one R is a moiety according to formula II.