A compound that is of the formula (FX1): ** Formula ** where: R1 and R3 are each independently -H, - (CH2) to (CH2CH2O) 5 bR5, - (CH2CH2O) bR5, -CH (COOH ) CH2OH or - (CH2) aY1； each Y1 is independently -OR6, - (CHOH) cR7, -NR8R9, -CONR8R9, -NHCO (CHOH) cR7 or - NHCO (CH2) to (CH2CH2O) bR5； each of R2, R4, R5, R6 and R7 are independently -H or C1-C6 alkyl； R8 and R9 are independently -H, C1-C3 alkyl, - (CH2) to (CHOH) cR7, or - (CH2) to (CH2CH2O) bR5； each a and c is independently an integer selected from the range of 0 to 6； each b is independently an integer selected from the range of 1 to 120； each p and q is independently an integer selected from the range of 0 to 120； each of m and n is independently an integer selected from the range of 3 to 6.Un compuesto que es de la fórmula (FX1):**Fórmula** en donde: R1 y R3 son cada uno independientemente -H, -(CH2)a(CH2CH2O)5 bR5, -(CH2CH2O)bR5, -CH(COOH)CH2OH o - (CH2)aY1； cada Y1 es independientemente -OR6, -(CHOH)cR7, -NR8R9, -CONR8R9, -NHCO(CHOH)cR7 o - NHCO(CH2)a(CH2CH2O)bR5； cada uno de R2, R4, R5, R6 y R7 son independientemente -H o alquilo C1-C6； R8 y R9 son independientemente -H, alquilo C1-C3, -(CH2)a(CHOH)cR7, o -(CH2)a(CH2CH2O)bR5； cada a y c es independientemente un número entero seleccionado del intervalo de 0 a 6； cada b es independientemente un número entero seleccionado del intervalo de 1 a 120； cada p y q es independientemente un número entero seleccionado del intervalo de 0 a 120； cada uno de m y n es independientemente un número entero seleccionado del intervalo de 3 a 6.
