D,L-乳酸聚合工艺研究

Study on polymerization process of D,L-lactic acid

以D,L-乳酸为原料,采用直接熔融聚合法制备聚乳酸(PDLLA),研究了催化剂种类、用量,聚合时间和温度等工艺条件对PDLLA相对分子质量的影响,并对PDLLA的性能进行了表征。结果表明,以质量分数0．5％(相对D,L-乳酸)氯化亚锡为催化剂,在175℃下反应10 h时,可得到相对分子质量较高的PDLLA。差示扫描量热测试表明,PDLLA无熔点,其玻璃化转变温度为52．72℃,属无定型结构。

Poly-D,L-lactic acid （PDLLA） was prepared from D,L-lactic acid via direct melt polymerization process. The effects of catalyst variety and amount and polymerization time and temperature on the relative molecular weight of PDLLA were studied. The properties of PDLLA were characterized. The results showed that the PDLLA with high relative molecular weight can be prepared by using 0.5% stannous chloride catalyst by mass fraction based on D ,L-lactic acid and reacting for 10 h at 175℃. The differential scanning calorimetric curves showed that PDLLA exhibited an amorphous structure with no melting point and glass transition temperature of 52.72℃.