竹粉的多元醇液化及其在半硬质聚氨酯泡沫中的应用

Liquefaction of Bamboo Powder in Polyols and Its Application in Preparation of Semi-rigid Polyurethane

研究了竹粉在多元醇中的液化反应,讨论了不同液化试剂,不同催化剂和不同反应条件对液化效果的影响,并分析探讨了各种条件下液化效率和液化产物的基本性质。实验结果表明:竹粉在聚乙二醇400中液化,当催化剂浓H2SO4质量分数为3%、液固质量比为5∶1,反应温度150℃时液化效率较高,液化反应180 min后其残渣率仅为0.8%,所得液化产物具有良好的流动性,液化生物质多元醇酸值为41 mg/g,羟值为178 mg/g。以液化竹粉多元醇和异氰酸酯(TDI)为原料,催化剂和助剂存在下,以NCO/OH为1.4制备了半硬质聚氨酯泡沫材料,所制备的聚氨酯泡沫材料的表观密度为69 kg/m3,50%永久压缩形变(22 h,70℃)为14.0%,泡沫体回弹性较好,为竹粉残材的应用提供了新途径。

Liquefaction of bamboo powder was conducted in polyols such as poly ethyleneglycol （PEG400）,ethylene glycol or glycerol using sulfuric acid catalyst.Effects of liquefying agents,types of catalyst and reaction conditions on the liquefaction procedure,were investigated in detail.The results showed thatthe yield of liquefied bamboo power was obtained when PEG400 was used as liquefaction solvent and 98 ％ sulfuric acid as catalyst.The residue rate for this case is low to 0.8 ％ in 180 min when the liquefaction was performed at 150 ℃ with 3 ％ catalyst and the ratio of PEG 400 to bamboo powder by weight of 5 ∶ 1.The resulting liquefaction bamboo products（LB） shows a hydroxy value of 178 mg/g,an acid value of 41 mg/g and excellent flowing property.Additionally,the abundant--OH groups that further conformed by infrared absorption spectrum,allowed this resulting LB to be used to prepare semi-rigid polyurethane （PU） foam.A semi-rigid polyurethane foam from LB and TDI （Toluylene Diisocyanate）（LB-PU） was then prepared using water as vesicant.These LB-PU forms had an apparent density of 69 kg/m3.In conclusion,our work on a new application of bamboo powder material has provided a novel way to develop the ＂green＂ polyurethane products.