US 9,097,971 B2  270  269  -continued  Synthesis of Polymeric Compound (47)  13.2 g of y-butyrolactone (GBL) was added to a flask  equipped with a thermometer, a reflux tube, a stirrer and a  nitrogen inlet tube under a nitrogen atmosphere, and the  internal temperature was raised to 85°  C. while stirring.  Separately from the above, 5 .0 g (15 .8 mmol) of monomer  (18), 4.6 g (19.5 mmol) of monomer (19), and 1.9 g (8.2  mmol) of monomer (20) were dissolved in 79.6 g ofy-buty› rolactone (GBL). Then, 0.72 g of dimethyl 2,2’-azobis(isobu- tyrate) (product name: V-601, manufactured by Waka Pure  Chemical Industries, Ltd.) as a radical polymerization initia› tor was added and dissolved in the obtained solution.  The mixed solution was added to the flask in a dropwise  manner at a constant rate over 4 hours, and then heated while  stirring for 1 hour, and the reacting solution was cooled to  room temperature.  The obtained reaction polymer solution was added to an  excess amount of a methanol/water mixed solution in a drop› wise manner so as to deposit a polymer. Thereafter, the pre› cipitated white powder was separated by filtration, followed  by washing with a methanol/water mixed solution and drying  under reduced pressure, thereby obtaining 8.1 g of a poly› meric compound (47) as an objective compound.  With respect to the polymeric compound, the weight aver› age molecular weight (Mw) and the dispersity (Mw/Mn)  were determined by the polystyrene equivalent value as mea› sured by gel permeation chromatography (GPC). As a result,  it was found that the weight average molecular weight was  6,900, and the dispersity was 1. 73.  Further, as a result of an analysis by  $^{13}$C-NMR, it was  found that the copolymer compositional ratio (ratio (molar  ratio) of the respective structural units within the structural  formula) was l/m/n=40/40/20.  Polymeric compounds ( 48) to ( 54) were produced in the  same manner as in Comparative Polymer Synthesis Example  1, except that the following monomers (18) to (29) which  derived the structural units constituting each polymeric com› pound were used with a molar ratio indicated in Table 24.  The weight average molecular weight (Mw) and the  molecular weight distribution (Mw/Mn) of the obtained poly› meric compounds ( 48) to (54) are shown in Table 24.  POLYMERIC COMPOUND (47)  Comparative Polymer Synthesis Example 1  Comparative Polymer Synthesis Examples 2 to 9  Synthesis of Polymeric Compounds ( 48) to ( 54)  [Chemical Formula 108]  [Chemical Formula 109]  (19)  (18)  ~o  0~  ~  0--s:::::::, 0  II  0  (18)  (V-601)  RADICAL POLYMERIZATION  (20)  ~o ~o ~o  0  0  0  O~  1G  0-S  11~0  0 