质量标准: |
聚乙烯醇1788型(average M.W. 88000 ): 外观Appearance 微黄色至乳白色粉末 醇解度degree of hydrolysis,%(mol/mol) 87.0~89.0 粘度Viscosity,mPa·s 20.5~24.5(4% 水溶液, 20°C) 乙酸钠Sodium acetate ,% ≤ 1.0 挥发分Volatile matter ,% ≤ 5.0 灰分Ash,% ≤ 0.4 PH值 5~7 聚乙烯醇1788低粘度型(average M.W. 22000 ):
外观Appearance 类白色至微黄色粉末 醇解度degree of hydrolysis,%(mol/mol) 87.0~89.0 粘度Viscosity,mPa·s 4.6-5.4(4% 水溶液, 20°C) 挥发分Volatile matter ,% ≤ 5.0 灰分Ash,% ≤ 0.4 PH值 5~7 聚乙烯醇1799型:
外观Appearance 白色至微黄色颗粒或颗粒粉末 醇解度degree of hydrolysis,%(mol/mol) 98~99 粘度Viscosity,mPa·s 22.0~28.0(4% 水溶液, 20°C) 乙酸钠Sodium acetate ,% ≤ 1.0 挥发分Volatile matter ,% ≤ 8.0 灰分Ash,% ≤ 0.7 聚乙烯醇1797型:
外观Appearance 白色至微黄色颗粒、结晶或粉末 醇解度degree of hydrolysis,%(mol/mol) 96.0~98.0 粘度Viscosity,mPa·s 23.0~29.0(4% 水溶液, 20°C) 乙酸钠Sodium acetate ,% ≤ 1.5 挥发分Volatile matter ,% ≤ 7.0 灰分Ash,% ≤ 0.7 PH值 5~7 |