Dear Monireh Alizadeh,

well, the question is not really clear. Even though, polyesterification reactions are acid catalyzed. Other catalysts include triphenylphosphine and derivatives, picryl chloride, DBU, and others. Regards

It depends on your reactants. Generally, Zn, Co, Mn acetates or tin organics such as di-n-butyl tin diacetate are recommended. Further information maybe obtained from Ullmann's Encyclopedia of technical chemistry.

 p-toluene sulfonic or methane sulfonic acids are often used at industrial scale. 

As stated in the previous comment, tributyltin may also be used to finish the reaction off

Best regards

one of the best kind of catalyst can be Ti-alcoxylates like Ti-n-butilate.With them there is no need to neutralize like with the acids.

Greetings,