A solvent-free process for preparing a copolymer (P1) of formula (L): wherein - each R 1 is independently selected from the group consisting of a halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium; - each i is independently selected from 0 to 4; - T is selected from the group consisting of a bond, -CH 2 -; -O-; -SO 2 -; -S-; -C(O)-; -C(CH 3 ) 2 - ;-C(CF 3 ) 2 -; -C(=CCl 2 )-; -C(CH 3 )(CH 2 CH 2 COOH)-; -N=N-; -R a C=CR b -, where each R a and R b , independently of one another, is a hydrogen or a C1-C12-alkyl, C1-C12-alkoxy, or C6-C18-aryl group; -(CH 2 ) m - and -(CF 2 ) m -with m being an integer from 1 to 6; an aliphatic divalent group, linear or branched, of up to 6 carbon atoms; and combinations thereof; - n p and n r are respectively the moles % of each recurring units p and r; recurring units p and r are arranged in blocks, in alternation or randomly; 5 ≤ n p < 100 ; 5 ≤ n r < 100 ; - q 1 and q 2 independently vary between 2 and 14, inclusive, comprising reacting via melt hydrosilylation, in a reaction mixture, a poly(aryl ether sulfone) (PAES) polymer (P0) comprising: - recurring units p of formula (N): and - at least one terminal group of formula (M): wherein R 1 , i and T are as above-mentioned and s varies between 0 and 12, inclusive; with a compound of formula (I): wherein m varies between 1 and 200; wherein the molar ratio of compound (I)/polymer (P0) is 0.5:1 and 1:0.5; optionally in the presence of a metal based catalyst; at a temperature ranging from 150 and 450°C, in the absence of a solvent selected from the group consisting of anisole, dimethylformamide, dimethyl sulfoxide, sulfolane, N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, or in the presence of less than 5 wt.% of said solvent based on the total weight of the reaction mixture. - each R 1 is independently selected from the group consisting of a halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium; - each i is independently selected from 0 to 4; - T is selected from the group consisting of a bond, -CH 2 -; -O-; -SO 2 -; -S-; -C(O)-; -C(CH 3 ) 2 - ;-C(CF 3 ) 2 -; -C(=CCl 2 )-; -C(CH 3 )(CH 2 CH 2 COOH)-; -N=N-; -R a C=CR b -, where each R a and R b , independently of one another, is a hydrogen or a C1-C12-alkyl, C1-C12-alkoxy, or C6-C18-aryl group; -(CH 2 ) m - and -(CF 2 ) m -with m being an integer from 1 to 6; an aliphatic divalent group, linear or branched, of up to 6 carbon atoms; and combinations thereof; - n p and n r are respectively the moles % of each recurring units p and r; recurring units p and r are arranged in blocks, in alternation or randomly; 5 ≤ n p < 100 ; 5 ≤ n r < 100 ; - q 1 and q 2 independently vary between 2 and 14, inclusive, - recurring units p of formula (N): and - at least one terminal group of formula (M): wherein m varies between 1 and 200; wherein the molar ratio of compound (I)/polymer (P0) is 0.5:1 and 1:0.5; optionally in the presence of a metal based catalyst; at a temperature ranging from 150 and 450°C, in the absence of a solvent selected from the group consisting of anisole, dimethylformamide, dimethyl sulfoxide, sulfolane, N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, or in the presence of less than 5 wt.% of said solvent based on the total weight of the reaction mixture. <EOS>