Preparation of polytrimethylene ether glycol and copolymers thereof

A process for producing polytrimethylene ether glycol comprising:

• A) forming a reaction mixture comprising (1) a 1,3-propanediol reactant selected from the group consisting of 1,3-propanediol, oligomers of 1,3-propanediol having a degree of polymerization of 2-9, and mixtures of the 1,3-propanediol and said oligomers, (2) at least one polycondensation catalyst and (3) at least one ionic liquid comprised of an ammonium cation and an anion having the Formula:
• wherein:
• (i) Z is —(CH2)n—, wherein n is an integer from 2 to 12;
• (ii) R2, R3 and R4 taken independently are H, —CH3, —CH2CH3 or C3 to C6 straight-chain or branched monovalent alkyl;
• and
• (iii) A− is R5—SO3− or (R6—SO2)2N−;
• wherein R5 and R6 are independently selected from the group consisting of:
• (a) —CH3, —C2H5, or C3 to C25 straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH2 and SH;
• (b) —CH3, —C2H5, or C3 to C25 straight-chain, branched or cyclic alkane or alkene comprising one to three heteroatoms selected from the group consisting of O, N and S, and optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH2 and SH;
• (c) C6 to C25 unsubstituted aryl or unsubstituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N and S;
• and
• (d) C6 to C25 substituted aryl or substituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N and S;
• and wherein said substituted aryl or substituted heteroaryl has one to three substituents independently selected from the group consisting of:
• (1) —CH3, —C2H5, or C3 to C25 straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH2 and SH,
• (2) OH,
• (3) NH2, and
• (4) SH;
• thereby forming a polyether phase comprising at least one polytrimethylene ether glycol and an ionic liquid phase that comprises the at least one polycondensation catalyst;
• and
• B) separating the polyether phase from the ionic liquid phase, thereby forming a separated ionic liquid phase.