基于响应面法的菌草重组材制备工艺优化

Preparation process optimization for Juncao scrimber via response surface methodology

菌草资源是目前世界上最丰富的农业资源之一,具有广阔的发展前景。以菌草绿洲一号为原料,制备菌草重组材,采用响应面Box-Behnken试验设计方法研究不同浸胶时间、热压时间、热压温度对菌草重组材主要物理力学性能的影响。在响应面试验结果基础上增加碱处理和帚化处理,探究改性对菌草表面结构及物理力学性能的影响。结果表明,菌草重组材的较佳制备工艺参数为浸胶时间33 min,热压时间1.12 min/mm,热压温度155℃。帚化制备的菌草重组材浸胶时间降低至15 min,其静曲强度(MOR)136.56 MPa和弹性模量(MOE)14.80 GPa比未帚化制备的菌草重组材分别提高154%和14%;吸水厚度膨胀率(TSR)5.84%和吸水宽度膨胀率(WSR)0.93%分别比未帚化制备的菌草重组材降低7和1.82个百分点,均达到GB/T 40247—2021《重组竹》的要求。碱处理试验结果显示,在NaOH质量分数为2%时MOR和MOE最佳,分别143.13 MPa和15.05 GPa;在NaOH质量分数1%时TSR和WSR最低,分别为1.85%和0.30%。通过扫描电镜分析可知,碱处理后菌草表面蜡质层出现降解,粗糙度增加;帚化处理产生的裂隙有利于酚醛树脂胶黏剂渗透到菌草内部,有利于菌草重组材的胶合,提高了力学性能和耐水性。本研究制备的菌草重组材为菌草新材料的开发提供新途径,对加快推进菌草重组材产业发展具有重要意义。

Juncao resources are one of the most abundant agricultural resources in the world,which have broad prospects for development,but there is a lack of research for reasonable and effective application strategies.The response surface Box-Behnken design methodology was used to study the effects of different impregnation time,hot-pressing time and hot-pressing temperature on the main physical and mechanical properties of the Juncao(Arund donax cv.lvzhou No.1) scrimber.Based on the design methodology test results,alkali and brooming treatment were added to explore the different effect of modification on the surface structure and main physical and mechanical properties of the Juncao.The results showed that the best preparation process parameters were the impregnation time of 33 min,hot-pressing time of 1.12 min/mm and hot-pressing temperature of 155 ℃.With the decrease of the impregnation time,the modulus of rupture(MOR) and modulus of elasticity(MOE) of the broomed Juncao scrimber showed a parabolic change trend,with few changes in width swelling rate(WSR).The impregnation time of the broomed Juncao scrimber was reduced to 15 min.MOR and MOE were 136.56 MPa and 14.80 GPa,respectively,which were 154% and 14% higher than those of non-broomed Juncao scrimber.TSR and WSR were 5.84% and 0.93%,which were decreased by 7 and 1.82 percentage points,respectively.Both properties met requirements of the standard GB/T 40247-2021 “Bamboo scrimber”.Brooming treatment enables the Juncao scrimber to have a denser laminated structure.The results of alkali treatment showed that MOR(143.13 MPa) and MOE(15.05 GPa) were the best when they were treated by the alkali solution with 2% NaOH mass ratio.The optimal TSR(1.85%) and WSR(0.30%) were obtained at the solution with 1% NaOH mass ratio.Scanning electron microscope(SEM) analysis showed that the surface wax layer of Juncao was degraded and the roughness increased after the alkali treatment,and it did not have da-mage to the internal fibers of Juncao.After the brooming treatment,the phenol formaldehyde resin can penetrate the fiber inside the Juncao through the cracks generated.The cracks caused by brooming were conducive to the penetration of the phenolic resin into the interior of the Juncao,which was advantageous to the bonding of the Juncao scrimber and improved the main physical mechanical properties and water resistance.The Juncao scrimber prepared in this study provides a new way for the development of new Juncao materials and is of great significance to accelerate the development of the Juncao scrimber industry.