The esterification of polyvinyl alcohol (PVA) and phosphoric acid to prepare polyanionic in the presence of urea as a catalyst is studied in this paper.是什么意思_The esterification of polyvinyl alcohol (PVA) and phosphoric acid to prepare polyanionic in the presence of urea as a catalyst is studied in this paper.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句