| 摘要 |
A process for purifying a polyol(per)fluoropolyether derivative [polyol (P)] from a mixture (M) of hydroxyl(per)fluoropolyether derivatives, such polyol (P) comprising one or more hydroxyl(per)fluoropolyether derivatives [PFPEs (OH)] comprising at least one (per)fluoropolyoxyalkylene chain (chain Rf) and at least one end-group having formula (t3): —CF2CH2OCH2CH(OH)CH2OCH2CH(OH)CH2OH, such mixture (M) comprising said polyol (P) and at least one hydroxyl(per)fluoropolyether derivative [PFPE (OH)] different from polyol (P) and comprising at least one chain Rf and at least one end-group selected from end-groups having formula (t1): —CF2CH2OH and formula (t2): —CF2CH2OCH2CH(OH)CH2OH. The process comprises the following steps: 1) reacting the mixture (M) with a ketone, an aldehyde, or a combination thereof to yield corresponding mixture of cyclic ketal/acetal(per)fluoropolyether derivatives [PFPEs (OH)p] [protected mixture (P)]; 2): submitting the protected mixture (P) to adsorption on silica gel to yield an adsorbed protected product [adsorbed product (Pp)] and then recovering a desorbed protected product [desorbed product (Pp)] by subsequent desorption from silica gel of the adsorbed product (Pp); 3) distilling the desorbed product (Pp) under reduced pressure to isolate a protected product residue [product (Pr)]; and 4) hydrolyzing the product (Pr) to obtain polyol (P). |
