I intend to achieve a lipophilic balance in polyvinyl alcohol so that in an aqueous solution of polyvinyl alcohol, the solution does not become so viscous to apply in a research of Solution Blow Spinning.
No, it is not possible. An esterfication reaction , by default, requires a strong acidic catalyst, heating, and a long time to give a reasonable yield for simple organic molecules.
In polymer analogous conversion (i.e. from polymer to another polymer), there are complications that arise from chain entanglements plus the intra- & inter- molecular attractive forces.
The norm is to apply stirring as the reaction proceeds but the polymer chemist expects a low degree of conversion. When PVA is subjected to heat, its color changes from whitish to yellowish which is indicative of an undesired internal reaction.
Schotten-Baumann reaction could be used to convert an acyl halide or anhydride to an ester if reacted with an alcohol and base.
Oleic acid chloride will be prepared first by reacting the fatty acid with a chlorinating agent such as PCl3 or PCl5 or SOCl2 or oxalyl chloride. I do not recommend phosgene, at all, in this chlorination.
After obtaining oleic acid chloride, it has to be reacted at once with poly(vinyl alcohol). A base (such as pyridine or triethylamine) may be used as scavenger for the side product (HCl).
I think that this reaction pathway is good to follow since there is no need for heating or catalysis & there will be no equilibrium. It will be interesting to know what will be the degree of conversion or the percentage yield.