Purity, content of propionaldehyde and colourity in PDO are main factors to yellowish and intrinsic viscosity of PTT resin.是什么意思_Purity, content of propionaldehyde and colourity in PDO are main factors to yellowish and intrinsic viscosity of PTT resin.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句