Isophthalic anhydride

Example 6

13.6 g of a PEG-PPG-PEG block copolymer with —OH group functionality at each terminal end and having 1100 Daltons Mw (0.0124 moles) that is obtained from Sigma-Aldrich, 33.2 g of neopentyl glycol (0.31 moles, Sigma-Aldrich), and 54.5 g of isophthalic anhydride (0.33 moles, Sigma-Aldrich) were weighed into a 250 ml 4-necked round bottom flask equipped with a heating mantle, overhead stirrer, temperature sensor, gas inlet, and a Dean-Stark trap with a condenser. The reaction was heated to 100° C. under a nitrogen atmosphere and 0.4 g p-toluene sulfonic acid monohydrate (0.002 moles, Sigma-Aldrich) as catalyst was added. The reaction was heated to 170-180° C. for 7 hours. The alkoxylated polymer resin that was produced was soft and tacky and had Mw of 2210 Daltons.

Example 7

13.6 g of a PEG-PPG-PEG block copolymer with —OH group functionality at each terminal end and having 1100 Daltons Mw (0.0124 moles) that is obtained from Sigma-Aldrich, 54.1 g of neopentyl glycol (0.52 moles, Sigma-Aldrich), 54.5 g of isophthalic anhydride (0.33 moles, Sigma-Aldrich), and 29.6 g of phthalic anhydride (0.20 moles, Sigma-Aldrich) were weighed into a 250 ml 4-necked round bottom flask equipped with a heating mantle, overhead stirrer, temperature sensor, gas inlet, and a Dean-Stark trap with a condenser. The reaction was heated to 100° C. under a nitrogen atmosphere and 0.4 g p-toluene sulfonic acid monohydrate (0.002 moles, Sigma-Aldrich) as catalyst was added. The reaction was heated to 170-180° C. for 7 hours. The alkoxylated polymer resin that was produced had Mw of 3660 Daltons. Example 7 represents a lower percentage of propoxylation (lower weight % of polypropylene glycol in the starting block copolymer, and conversely, greater weight % of polyethylene glycol).