改性木质纤维土壤保水材料的制备及性能研究

Study on Preparation and Performances of Modified Wood Fiber Soil Water Retention Materials

关键词:  木粉  聚谷氨酸  紫外光聚合  复合土壤保水材料

Key Words:wood powder  polyglutamic acid  UV polymerization  composite soil water retention material

摘要:本研究以木材加工过程中产生的木粉为纤维来源，通过化学热磨机械制浆法预处理及碱性过氧化氢漂白后，经TEMPO氧化及胶体磨处理得到改性木质纤维（CRF）。随后与聚谷氨酸（PGA）、丙烯酸（AA）和丙烯酰胺（AM）通过紫外光聚合，制备复合土壤保水材料（PGA-CRF/SWR）。结果表明，添加6%的CRF可显著提高土壤保水材料的力学性能，压缩强度由0.010 8 MPa提高到0.035 1 MPa。并且随着PGA用量由3%增加到12%时，压缩强度进一步提高到0.046 7 MPa。在水温为30 ℃、pH值为7时，PGA-CRF /SWR的吸水倍率和保水倍率达到最佳，并且当CRF和PGA用量均为6%时，PGA-CRF /SWR在去离子水和自来水中的最佳吸水倍率分别为688.5和298.7 g/g，保水倍率为655.7和277.9 g/g；经过5次吸水润胀循环后吸水倍率仍能达到初始的62.2%；土壤掩埋60天后剩余质量为79.2%；在温度低于309.1 ℃时表现出良好的热稳定性。

Abstract:In this study， wood powder produced during wood processing was used as the fiber source. After pretreatment by chemical thermomechanical pulping and alkaline hydrogen peroxide bleaching， modified wood fiber （CRF） was obtained by TEMPO oxidation and colloid milling. Subsequently， the composite soil water retention material （PGA-CRF/SWR） was prepared by ultraviolet polymerization with polyglutamic acid （PGA）， acrylic acid （AA）， and acrylamide （AM）. The results showed that adding CRF with the dosage of 6% could significantly improve the mechanical properties of the soil water retention material， and the compressive strength increased from 0.010 8 MPa to 0.035 1 MPa. As the dosage of PGA increased from 3% to 12%， the compressive strength further increased to 0.046 7 MPa. When the pH value was 7 and the water temperature was 30 ℃， the water absorption rate and water retention rate of PGA-CRF/SWR reached the best， and when the dosages of CRF and PGA were both 6%， the best water absorption rate of PGA-CRF /SWR in deionized water and tap water were 688.5 and 298.7 g/g， respectively， and the water retention rate were 655.7 and 277.9 g/g. After 5 cycles of water absorption and swelling， the water absorption rate could still reach 62.2% of the initial value， the residual mass after soil burial for 60 days was 79.2%， which showed good thermal stability before 309.1 ℃.