不同液化条件对毛竹粉多元醇液化产物分子量的影响

Effects of Various Reaction Parameters during Bamboo Powder Liquefaction with Polyhydric Alcohols on Molecular Weight and Polydispersity

以PEG400/Glycerin为液化剂,硫酸为催化剂,研究液化反应条件对竹粉液化产物分子量的影响。结果表明:液化反应体系中液固质量比从2∶1增加到4∶1时,液化产物的重均分子量Mw和分散度Mw/Mn逐渐减小;催化剂硫酸用量从2%增加到3%时,液化产物的重均分子量Mw和分散度Mw/Mn先减小,硫酸用量达到4%时又增大;液化反应温度从130℃升高到140℃时,液化产物的重均分子量Mw和分散度Mw/Mn先减小,到150℃又增大,160℃开始逐渐减小;随着液化反应时间的延长,液化产物的重均分子量Mw和分散度Mw/Mn先减小后增大直到120min时又减小。这说明液化反应时间、温度、液固比、催化剂用量对竹粉降解产物分子量及其分布均有影响。

The effects of the liquefying condition on molecular weight of bamboo powder liquefaction product which liquefying with polyalcohol400 and glycerin as liquefier and sulfuric acid as catalyst were studied. Experiments showed that ：the weight-average molecular weight （Mw） and polydispersity （Mw/Mn） decreased firstly and increased with enhancing of H2SO4 until H2SO4 concentration reached 4% where Mw and polydispersity decreased continuously. As the ratio of liquid to solid increased,Mw and polydispersity decreased continuously; the weight-average molecular weight （Mw） and polydispersity （Mw/Mn） of copolymer decreased firstly and increased when the reaction temperature reached 150 ℃ and then decreased till the temperature reached 160 ℃; the weight-average molecular weight （Mw） and polydispersity decreased firstly and then increased until the reaction duration reached 120 min. The results indicated that the weight-average molecular weight （Mw） and polydispersity （Mw/Mn） were influenced by reaction time,temperature,the ratio of liquid to solid and H2SO4.