Feb.28,2019  56  US 2019/0064665 Al  a non-aromatic ring with the carbon atoms to which they are  attached. In this event,  Re 4 ,  Res and the carbon atoms to  which they are attached together represent a trivalent  organic group of3 to 12 carbon atoms in total.  Re $^{6 }$is a single  bond or a C$_{1 }$-C$_{4 }$ alkylene.  [0208]  Re $^{7 }$is each independently a single bond, ---0-, or  -CRe$^{1}$Re 1 -. Re 8  is a straight or branched C$_{1}$-C$_{4 }$ alkylene  group, or may bond with Re $^{2 }$within a common unit to form  a C$_{3}$ -C$_{6 }$ non-aromatic ring with the carbon atom to which  they are attached.  [0209]  Re $^{9 }$is methylene, 1,2-ethylene, 1,3-propylene or  1,4-butylene. Re 10  is a C$_{3}$ -C$_{6 }$ linear perfluoroalkyl group,  typically 3H-perfluoropropyl, 4H-perfluorobutyl, 5H-per› fluoropentyl or 6H-perfluorohexyl.  [0210]  U  is each independently ----C(=0)---0-, ---0-,  or -C(=0)-Re $^{11}$-C(=0)-0- wherein Rell is a  straight, branched or cyclic C$_{1 }$-C$_{10 }$ alkylene group. The  subscripts are in the range: 0s(a’-l)sl, 0s(a’-2)sl, 0s(a’-3)  sl, 0sb’sl, 0sc’sl, and 0s(a’-l)+(a’-2)+(a’-3)+b’+c’sl.  [0211]  Examples of these recurring units are shown below,  but not limited thereto. Herein  Re 1  is as defined above.  [0212]  The polymeric surfactant has a Mw of preferably  1,000 to 50,000, more preferably 2,000 to 20,000 as mea› sured by GPC versus polystyrene standards. A surfactant  with a Mw within the range may be effective for surface  modification and cause no development defects.  (++)  H  ’)==a  - TF3 oh  HO/V  F3C  (++)  H  ’)==a  0  \  (++)  H  ’)==a  0  (++)  H  ’)==a  0  >-CF3  F3C 