生物质改性淀粉基木材胶粘剂制备及性能研究

以玉米淀粉为原料,H_2O_2为氧化剂,利用新型生物质花生蛋白作为改性剂制得花生粕改性淀粉基胶黏剂。通过单因素实验及正交设计实验进行优化,得到最佳实验条件为:淀粉氧化剂双氧水含量1%、花生粕占比10%(相对于淀粉的质量分数)、pH值为9.0、反应温度为40℃。在该实验条件下得到胶黏剂的胶合强度为4.58 kg/m~2,耐水时间为20 h。实验结果表明:花生粕改性淀粉基胶黏剂的胶合强度和耐水性能均明显好于纯氧化淀粉胶黏剂。     

环氧化合物改性大豆蛋白胶黏剂制备工艺与性能研究

通过三羟甲基丙烷三缩水甘油醚(THPTG)交联聚合大豆蛋白降解液制备低黏度大豆蛋白胶黏剂,研究THPTG用量、反应时间、反应温度等工艺参数对大豆蛋白胶黏剂黏度、耐水胶合强度和固化性能的影响,优化大豆蛋白胶黏剂制备工艺条件。结果表明:THPTG用量与反应时间对大豆蛋白胶黏剂黏度、耐水胶合强度均有显著影响,而反应温度仅对黏度影响较大;THPTG用量为9%时,大豆蛋白胶黏剂固化温度为130.20℃,固化反应热达到最大值199.7 J/g。大豆蛋白胶黏剂优化的制备工艺条件为THPTG 9%、反应时间50 min、反应温度70℃,制备的胶黏剂黏度为106 mPa·s,耐水胶合强度达到0.76 MPa,满足GB/T 9846—2015对于Ⅱ类胶合板标准要求。     

利用脱脂豆粉制备木材胶黏剂合成工艺初探

由于世界范围内石油资源的紧缺和传统木材用胶黏剂引发的环境问题,使得木材胶黏剂工业重新重视研发豆基胶黏剂。笔者以脱脂豆粉为原料,以尿素、戊二醛为改性试剂制备复合改性木材胶黏剂。分别探讨了尿素浓度、反应温度、反应时间以及戊二醛添加量对改性胶黏剂胶合性能及耐水性的影响,并采用FT-IR分析复合改性胶黏剂样品中活性基团的变化,探索耐水胶合强度增强机理。通过试验结果分析,在试验研究范围内较优合成工艺参数为:尿素浓度为2.0M、反应时间1.0h、反应温度40℃、戊二醛添加量为2.0%(以脱脂豆粉质量为基准)。经30℃热水浸泡处理后,胶合强度达到0.85MPa。     

半纤维素酶/漆酶协同预处理工艺对竹刨花自生胶合性能的影响

研究半纤维素酶和漆酶的酶用量、缓冲溶液pH值、处理温度和时间对竹材自生胶合刨花板内结合强度的影响,结果表明:半纤维素酶/漆酶预处理主要参数对竹刨花自生胶合性能有不同程度影响,酶用量影响最显著。优化预处理参数为:处理温度60～70℃,半纤维素酶用量约500IU/g,缓冲溶液pH为9,处理时间45min,漆酶用量约30IU/g,缓冲溶液pH=3～4,处理时间120min。该结论可为半纤维素酶/漆酶协同预处理竹刨花制造自生胶合刨花板提供理论指导。     

花生壳苯酚液化物-甲醛树脂胶用于集装箱底板试验

花生壳苯酚液化物-甲醛树脂胶粘剂是花生壳粉苯酚液化后的高反应活性产物与甲醛缩聚而成的高耐水性木材胶粘剂.探讨了花生壳苯酚液化物-甲醛树脂胶粘剂用于集装箱底板生产的最佳胶合工艺,检测了集装箱底板的各项物理力学性能和耐老化性能,并与传统酚醛胶及落叶松单宁胶进行了成本对比分析.结果表明,花生壳苯酚液化物-甲醛树脂胶粘剂的最佳胶合工艺为双面施胶量350 g/m2,热压时间1.2 min/mm,热压温度140℃;在此热压工艺条件下压制的集装箱底板的各项物理力学性能可以满足国家标准的要求,具有胶合强度高、耐老化性能优异、成本低廉等优点.     

不同脲醛树脂对竹胶板性能影响

木材用脲醛树脂基本适用竹材胶合,但需改善耐水性能;竹席胶合板的静曲强度和脲醛树脂的固体含量及粘度有关,通常随二者增大而增大,粘度过大反而降低,故宜选用固体含量55%、粘度60—80cPa·s、pH7.0的脲醛树脂。     

酶辅助提取协同大孔树脂纯化红麸杨果实黄颜木素

红麸杨果实经纤维素酶处理后,采用体积分数70%乙醇-大孔吸附树脂联用技术对黄颜木素进行提取、纯化,以黄颜木素得率为考察指标,采用正交试验优化了酶辅助提取工艺,并从8种大孔吸附树脂中筛选出对黄颜木素分离纯化最佳的树脂,研究了该树脂对黄颜木素静态、动态吸附与解吸效果。结果表明:酶处理的最佳条件为酶用量120 U/mL,酶解温度55℃,酶解时间60 min,酶解pH值4.5,黄颜木素得率可达1.35%,纯度为14.59%。通过静态吸附试验筛选出最有效的XDA-8树脂用于黄颜木素的纯化,XDA-8分离纯化黄颜木素动态吸附试验的最佳条件为上样质量浓度14.4 g/L,流速80.384 mL/h,洗脱液乙醇体积分数为60%,洗脱液流速80.384 mL/h,解吸率为91.86%,纯化后黄颜木素纯度达到了68.15%。     

刨切薄竹载药量对薄竹胶合板力学性能的影响

利用复配阻燃剂研究了浸渍温度、浸渍时间及浸渍浓度对刨切薄竹载药量的影响,并测试了不同载药量薄竹胶合板的力学性能。结果表明:在温度60℃,时间8 h,浸渍浓度30%时为最佳浸渍条件;力学性能测试表明,经过阻燃处理的薄竹胶合板随着载药量的增加其胶合强度有所下降,未处理试样的胶合强度为0.85 MPa,含水率为11.0%,经阻燃处理载药量为6%、8%、10%、12%的胶合板胶合强度依次为0.75 MPa、0.71 MPa、0.64 MPa、0.58 MPa,分别下降了11.8%、16.5%、24.7%、31.8%,含水率范围为12.3%~13.2%。当载药量为6%和8%时胶合强度满足普通胶合板的国标指标值,即≥0.70MPa;综合含水率和胶合强度可知8%为最佳载药量。     

酶法降解黑木耳多糖工艺研究

采用酶法对黑木耳多糖进行降解试验研究。用β-葡萄糖苷酶以温度、pH值、酶用量、反应时间为影响因素,响应面法优化设计,DNS法测定其还原糖释放量。研究结果表明:最佳工艺为当每3mL多糖加入0.02%葡萄糖苷酶0.4mL时多糖浓度为0.3%、温度55℃、pH值5.5、反应时间20min。响应面优化后得出最佳工艺条件为:降解温度55.9℃、pH值5.58、酶用量0.475mL。     

红锥木材性质与胶合强度的关系

通过对红锥木材性质与胶合强度的测定和分析 ,结果表明 :胶合强度与木材的pH值和碱缓冲容量在0 0 1水平上相关显著 ,与酸缓冲容量和木材的物理力学性质之间的相关程度均未达到显著水平。研究结果为红锥木材培育和合理利用提供了科学依据。     

Preparation and Properties of Plywood Adhesives with Soy Protein Isolate Modified by SDS

The effects of mass concentration,the reaction temperature and the reaction time of soy protein isolate(SPI) and sodium dodecyl sulfate (SDS) on the adhesive strength of the modified SPI adhesives has been studied through orthogonal experiments.And the adhesive mechanism of the modified SPI adhesives was discussed.The results show that the optimum formula conditions are as follows:mass concentration of SPI was 14%,that of SDS 1%,reaction temperature 35℃and the reaction time 3 h.Under the optimum conditions, the dry adhesive strength of the modified SPI adhesives was 1.82 MPa,the wet adhesive strength was 0.82 MPa,the viscosity was 5.8 Pa·s,the solid content was 12.96%.After SDS was added into SPI, the composites of SDS-SPI were formed,the internal hydrophobic groups among the SPI molecule structure were turned out and the water resistance of the modified SPI adhesives was enhanced with an increase of the modification time.When the concentration of SDS was over a defined value,the disulfide bond was broken and the modification effect of SDS went bad.     

核桃壳苯酚液化及其产物树脂化制备木材胶黏剂的研究

采用硫酸催化剂,考察了苯酚与核桃壳质量比等条件对核桃壳液化的影响。结果表明相同液化条件下,随着苯酚与核桃壳质量比从2∶1升至5∶1,残渣率从26.49%降至6.60%;随着浓硫酸加入量从2%增至4%、反应时间从5 min延至120 min、反应温度从100℃增至150℃,残渣率则分别从20.79%降至10.48%、48.84%降至15.62%、28.86%降至9.39%,游离酚含量分别从17.32%降至12.67%、41.71%降至10.25%、21.94%降至14.33%。同时,液化产物重均相对分子质量(MW)可降至706~1 030、分散度可降至1.04~1.25;液化产物中高相对分子质量部分随着苯酚与核桃壳质量比的增加有所降低,但随着浓硫酸加入量、液化反应时间和温度的增加而有所增加;核桃壳液化产物/苯酚/甲醛共缩聚树脂胶黏剂(WPF)与传统酚醛树脂胶黏剂(PF)的对比表明,WPF的胶接强度可达1.33 MPa,可作为胶合板用胶黏剂。     

提取骨碎补中柚皮苷的研究

采用超声波对骨碎补中的柚皮苷进行辅助提取,在单因素试验的基础上,应用Box-Behnken响应面优化设计,得到最适的超声提取工艺条件:按1∶24的料液比加入55%(V/V)乙醇溶液,在500W功率、70℃的温度下超声处理32min,在此条件下骨碎补中的柚皮苷的提取量为15.07mg/g。     

Acetylation of wood in combination with polysiloxanes to improve water-related and mechanical properties of wood

Scots pine sapwood was acetylated with ethyltriacetoxysilane using acetic acid as a solvent and sulfuric acid as a catalyst. A weight percent gain (WPG) of 14 % and cell wall bulking of 7 % were obtained after 5 h of reaction time. Pine specimens were acetylated with acetic anhydride in the presence of 1 % ethyltriacetoxysilane, dihydroxy-functional siloxane, acetoxy-functional siloxane, amino-functional siloxane and non-functional siloxane, respectively. Acetoxy-functional siloxane induced the greatest reduction in water uptake with a water repellent effectiveness after 24 h of up to 62 % as compared to acetylated wood. WPG and cell wall bulking increased compared to solely acetylated wood with increasing concentrations of acetoxy-functional siloxane in acetic anhydride; anti-shrink efficiency, however, did not increase. Fungal resistance of pine sapwood and beech as well as mechanical strength properties did not change when 20 % acetoxy-functional siloxane was added to acetic anhydride compared to solely acetylated specimens.     

玉米秸秆基吸油材料的制备与表征

以玉米秸秆(RCS)为原料,经氨水预处理得预处理玉米秸秆(PCS),再经乙酸酐酯化改性制备改性玉米秸秆(ECS)吸油材料,并考察不同酯化条件对产物吸油性能的影响。结果表明:RCS、PCS(预处理6 h)对0~#柴油的吸收倍率分别为1.90和4.43 g/g;以冰乙酸为溶剂,冰乙酸与乙酸酐质量比为1∶1,秸秆与冰乙酸-乙酸酐混合液的质量比为1∶15,催化剂浓硫酸用量为4.5%(以秸秆质量计),反应温度为110℃条件下,酯化反应5 h所得改性产物ECS的吸油率可达9.03 g/g,且ECS疏水性和漂浮性能均得到显著改善。采用XRD、FT-IR、SEM和BET等方法对预处理前后及酯化改性后秸秆进行了分析与表征。结果表明:酯化反应已顺利进行,酯化改性后秸秆呈非晶态,ECS呈均匀的介孔结构,介孔及粗糙表面的出现提高了材料的吸油率和漂浮性能。     

巯基纤维素处理重金属废水研究

纤维素与硫代乙醇酸在乙酸酐和乙酸介质中发生酯化反应，合成巯基纤维素(SC)。含重金属的废水中加入碱调节废水pH值至9～10，静置、过滤。滤液用酸调pH值至5～7后流经SC管，去除废水中镉、铅、铜、汞等重金属。SC用稀盐酸淋洗再生。对使用和再生条件及吸附机理进行了研究。实验结果：SC中巯基含量大于2％时，每公斤SC对金属离子的吸附容量大于0．2mol；处理水中镉、铅、铜、汞浓度低于0．05mg／L；SC再生后可循环使用。     

低温胁迫对喜树苗期叶生理指标的影响

以 1年生喜树苗为材料 ,研究了低温胁迫下喜树苗期叶SOD、Chl、MDA、pro含量的变化。结果表明 :10天 8℃低温胁迫下SOD活性、叶绿素含量分别比对照 (30℃± 2 )下降2 5 31%、11 91% ,丙二醛、脯氨酸含量比对照提高 14 82 %、50 72 % ;18天 4℃低温胁迫下SOD活性、叶绿素含量分别比对照下降 2 2 56 %、37 19% ,丙二醛、脯氨酸含量比对照提高2 9 4 2 %、58 72 %。     

华盖木多酚氧化酶酶学特性研究

以华盖木嫁接苗当年生茎段为试材提取PPO酶液,研究温度、pH值、底物邻苯二酚浓度及抑制物对PPO活性的影响。结果表明:华盖木多酚氧化酶的最适温度为35℃,最适pH值为7.0,温度和pH值过高或过低都会降低酶活性;邻苯二酚浓度为0.14 mo.lL-1时,PPO活性最大,低于0.14 mo.lL-1时,随底物浓度的增加,酶活性增加,超过0.14 mol.L-1时,加大底物浓度酶活性降低;Na2SO4、柠檬酸、抗坏血酸(Vc)对华盖木PPO的活性均有一定的抑制效果,其中Vc的抑制效果最显著。     

Properties of oriented strand board made from Betung bamboo (Dendrocalamus asper (Schultes.f) Backer ex Heyne)

Bamboo has gained increasing attention as an alternative raw material for use in the manufacture of composite boards. Three-layer OSBs were made using Betung bamboo (Dendrocalamus asper (Schultes.f) Backer ex Heyne) strands to evaluate the effects of strand length and pre-treatment techniques on the physical, mechanical, and durability properties. Three different strand lengths, namely 50, 60, and 70?mm, were prepared. Prior to the manufacture into OSB, the strands were immersed in cold water for 24?h and in 6% acetic anhydrides solution for 48?h. The OSBs were fabricated using 5% MDI resin based on the strand dry weight. The results indicated that MOR and MOE values in perpendicular to the grain direction were much influenced by strand length. The dimensional stability of OSB was slightly improved by immersing the strands in acetic anhydride solution. Immersing strands in cold water and acetic anhydride solution improved the resistance of OSB against subterranean termite (Macrotermes gylvus) attack under the adopted experimental condition. All OSB parameters manufactured in this experiment were better than the minimum requirement of CSA 0437.0 (Grade O–2) standard.