【作者】 朱本城；

【导师】 赵广杰；

【作者基本信息】 北京林业大学 ， 木材科学与技术， 2008， 博士

【摘要】 我国是一个森林资源相对贫乏的国家,随着国家经济的快速发展和人们对友好环境需求意识的增强,对木质材料的需求越来越大,木材的缺乏一直是我国木材工业发展的一个制约因素。我国木材加工的综合水平相对较低,许多木质材料加工厂有相当多的木材剩余物(刨花、锯末以及生产家具的边角料)没有得到充分的、有效的利用;由于城市化建设及旧城改造的加快,房屋动拆过程中会产生大量的木质废料,此外城市建筑以及居民住房装修等也会产生大量的废旧木质材料;工业产品、物流仓储、会议展览、百货超市以及交通等行业的废旧木质材料。这些废弃的木质材料基本上都直接扔掉或烧掉,不但造成了环境污染,同时也浪费了相当数量的生物质材料。如何利用废弃的木质材料这一生物质资源越来越受到重视。随着石油、煤炭和天然气等化石资源的日益枯竭,如何利用再生资源替代石油产品制备树脂化产品已成为国内外研究的热点。本论文采用苯酚为液化剂,在对比不同酸性催化剂对液化效果影响的基础上,选用浓硫酸作为催化剂,进行实验室自制刨花板和回收废弃刨花板的液化试验;分析了液化过程中的影响因素,采用正交试验方法确定了两种刨花板的优化液化工艺;采用两种刨花板液化物与甲醛在碱性条件下反应,制备得到了热固性的刨花板液化物树脂,并对树脂化过程中的影响因素和工艺进行了研究,对树脂的基本性能进行了比较分析,采用正交试验方法确定了两种刨花板液化物树脂化的优化合成工艺;利用多种仪器分析方法:扫描电子显微镜(SEM)、傅立叶转换红外光谱(FTIR)、核磁共振光谱(1H-NMR和13C-NMR)和差热分析仪(DTA)对液化物树脂的结构、性能表征进行了分析;对两种刨花板液化物的模压材料进行了抗压强度、耐水性能进行了比较分析。本论文得到以下结论:(1)根据对实验室自制刨花板和回收废弃刨花板水热处理液化残渣率及其红外光谱分析,研究得出优化水热处理条件是:实验室自制刨花板水热温度80℃,水热处理时间6小时;回收废弃刨花板水热温度80℃,水热处理时间8小时。(2)在研究两种刨花板苯酚液化过程中,选用硼酸(晶体)、盐酸(37%)、磷酸(85%)和浓硫酸(98%)等四种无机酸催化剂,利用液化后的残渣率和液化物中游离苯酚含量作为液化效率的指标,浓硫酸对刨花板苯酚液化的催化性能较好,可以在所选择的温度下实现刨花板的苯酚液化,磷酸作为刨花板苯酚液化的催化剂比盐酸、硼酸催化性能好,但也无法得到理想的液化效果。盐酸由于具有较强的挥发性,催化剂效果不如磷酸和浓硫酸,温度越高越明显,酸性较弱的硼酸,其催化性能最差,即使在温度180oC,催化剂用量10%的条件下,刨花板在苯酚中基本上不发生反应,液化效率极低。(3)利用残渣的结晶度来分析不同催化剂及其用量对刨花板液化效果的影响,残渣的结晶度越高说明催化剂对刨花板液化反应的催化效果越好,与相同液化条件下以游离苯酚含量和残渣率作为液化指标对液化效率的评价是一致的,得出浓硫酸是刨花板优化的催化剂。(4)对试验结果数据进行方差分析,筛选得到较理想的液化工艺参数,验证试验的结果是:回收的废弃刨花板在液化温度140℃、液化时间1.5hr、料液比(苯酚/刨花板粉)4.5、催化剂硫酸加入6%时,可得到低至9.6%的残渣率,即液化效率为90.4 %,液化物可被溴化物含量43.48%。实验室自制刨花板液化温度140℃、液化时间1.5hr、料液比(苯酚/刨花板粉)在相同的温度和液化时间条件下、但料液比(苯酚/刨花板)为3.5、催化剂硫酸加入量6 %时,残渣率为8.9 %,液化效率为91.1%,液化物可被溴化物含量39.65%。(5)采用正交试验方法进行树脂化试验,并对得到的树脂按照国家标准进行基本性能测定,对液化物树脂的一些指标进行采用极差分析,综合分析得出两种刨花板各自的优化树脂化工艺,随筛选后树脂化条件进行验证试验,确定出了两种刨花板液化物树脂化各自的优化树脂化合成的工艺参数。回收废弃刨花板液化物树脂的优化工艺条件为:树脂化时间2h,树脂化温度85℃,甲醛与回收废弃刨花板液化物物质的量比2.1,NaOH与回收废弃刨花板液化物物质的量比0.6,水与回收废弃刨花板液化物树脂的物质的量比9.0.实验室自制刨花板液化物树脂的优化工艺条件为:树脂化时间2.5h,树脂化温度90℃,甲醛与实验室自制刨花板液化物物质的量比1.8,NaOH与实验室自制刨花板液化物物质的量比0.5,水与实验室自制刨花板液化物树脂的物质的量比9.0.(6)采用SEM分析两种刨花板的液化物到树脂的过程,发现回收废弃刨花板液化物含有的颗粒状木质物质比实验室自制刨花板液化物中含有要大。两种刨花板液化物与甲醛树脂化得到的液化物树脂,均含有木质材料的成分,常规合成条件下合成的酚醛树脂中不含有木质材料成分。两种刨花板液化物树脂相比,回收废弃刨花板液化物树脂中含有的纤维状物质在形态上要比实验室自制刨花板液化物树脂中含有的要大。(7)两种刨花板液化物树脂和常规酚醛树脂的FTIR比较分析表明,三种树脂的吸收峰位置类似,只是强度有所不同。两种刨花板液化物树脂的吸收峰均高于酚醛树脂,也就是说两种刨花板液化物树脂中的官能团具有更高的活性。(8)三种树脂的1H-NMR谱图及其波谱归属相比,实验室自制刨花板液化物树脂和回收废弃刨花板液化物树脂含有大量的木质素单元,表明在树脂化生成过程中,木质素参与了树脂化过程的共缩聚反应,对比两种液化物树脂的核磁工作谱图,二者的差异没有太多变化,也就是说两种刨花板液化物合成的树脂在结构上没有太大差异,只是由于两种刨花板液化物的化学成分组成的不同引起某些基团含量上有所不同。(9)两种刨花板液化物树脂与常规的酚醛树脂13C-NMR谱图相比可以看出,实验室的酚醛树脂不但含有o,o Ph-CH-Ph和p,p Ph-CH-Ph结构,而且含有大量的木质素单元,表明在树脂合成过程中木质素与苯酚,甲醛发生了共缩聚反应,同时也有苯酚单元的自缩聚;而常规的酚醛树脂不含游离苯酚,回收废弃刨花板液化物,实验室液化物生产出的树脂出现了游离苯酚的化学位移,可见苯酚化的液化产物中的游离酚没有被完全地反应掉。对比两种刨花板液化物树脂的核磁共振谱图,可以见到二者的谱图基本没有太大的差异,这说明两种液化物树脂在结构上没有差异,只是在某些基团的含量上有所不同。(10)常规酚醛树脂的固化温度低于回收、制备的改性酚醛树脂,表明利用废弃刨花液化物制备酚醛的热行为介于常规树脂与实验树脂之间,随着实验的升温速率从5℃/min提高到20℃/min时,其放热峰逐渐向高的温度移动,且三者放热峰位置的差异性也越来越大,这表明不同实验条件对其热行为的影响也较大。(11)通过对模压时间、模压温度和木粉的加入量单因素分析对其液化物树脂模压材料力学性能的分析比较,得出优化的液化物模压工艺参数:模压时间为2h、模压温度120℃、木粉与树脂比为1:1。通过对液化物树脂模压材料与酚醛树脂模压材料在极限吸水率、吸水厚度膨胀率、极限体积膨胀率和24h吸水膨胀率的比较,液化物树脂模压材料更具有较好的耐水性能,回收刨花板液化物树脂模压材料与实验室刨花板液化物树脂模压材料的极限体积膨胀率变化不大,分别为7.3%和7.5%;极限吸水率分别为29.6%和31.2%;吸水厚度膨胀率分别为4.1%和3.3%,24h吸水率分别为13.3和14.5%。(12)回收废弃刨花板液化物树脂的原料成本比常规酚醛树脂低14.2%,每吨树脂节约695.47元,尽管在废弃刨花板回收过程中、前期的水热处理及其液化过程中需要消耗部分电能和水,但在树脂化过程和热压过程中都比酚醛树脂的工作温度低,综合考虑回收废弃刨花板液化物树脂在成本上有一定的优势。另外,可以节约资源,保护环境,产生的社会效益与生态效益更具有深远的意义。更多还原

【Abstract】 China is a country which is lack of forest resource, as the rapid development of national economic and the enhancement of environment-friendly consciousness, the demand of wood material more than before; the deficiency of wood is a bottleneck of Chinese complete economic development. The comprehensive of Chinese wood industry is much lower relatively, many wood factories produces lots of wood residues (wood chip, saw dust and remnant) which haven’t been comprehensive utilized effectively; as the acceleration of urbanization and old city rebuilding, many wood waste materials have been produced in the process of construction relocation, the same as city construction and citizen apartment decoration; industrial products, physical distribution and dock warehousing, meeting and exhibition, department and supermarket and traffic etc. these waste wood material have been abandoned or burned basically, not only to generate environmental pollution but also to waste many biomass materials. More focuses have been put on the problem of using waste wood material. As the depletion of petroleum, coal and gas and so on, how to produce resin product by renewable source instead of oil has become one hot issue in the world. The article has chosen phenol as liquoring agent, concentrated sulfuric acid has been selected after comparing the liquefaction effect of different acid catalysts; to proceed the liquefaction experiment of lab-synthesized Particleboards and recycled useless Particleboards; according to analyze the factors in the process of liquefaction, two optimum Particleboard liquefaction technologies have been settled by orthogonal experiment; according to take the reaction between the two Particleboard liquefaction products and formaldehyde in the alkaline condition, heat convertible Particleboard liquefaction resin has been produced and the effective factors and technology of the resinification process has been studied, as well as comparative analysis of resin basic characters, two optimum resinification synthesis technologies of Particleboard liquefaction product have been settled by orthogonal experiment. The liquefied resin structure, performance characterization has been analysed by many methods of instrumental analysis: SEM, FTIR, 1H-NMR and 13C-NMR, DTA; further comparative analysis of compression strength and hydrolytic resistance has been studied on the molding materials made by the two Particleboard liquefied products. The conclusions as follow:(1) According to the residue ratio of hydro-thermal treatment of lab-synthesized Particleboards and recycled useless Particleboards and infrared spectrum analysis, the optimum hydro-thermal treatment condition is, lab-synthesized Particleboards: temperature 80℃, time 6 hrs; recycled useless Particleboards: 80℃, time 8 hrs.(2) In the process of the two Particleboards liquefaction in phenol, four inorganic acids: boric acid (crystal), hydrochloric acid (37%), phosphoric acid (85%), concentrated sulfuric acid (98%), liquefaction efficiency index includes residue ratio after liquefaction and free phenol in liquefaction product, the catalytic performance of sulfuric acid on Particleboard liquefaction in phenol is better comparatively, which accomplish Particleboard liquefaction in phenol in set temperatures, the catalytic performance of phosphoric acid is better than hydrochloric acid and boric acid, but no ideal liquefaction effect at all. the catalytic performance of hydrochloric acid is worse than phosphoric acid and sulfuric acid as its high volatility, more obvious in higher temperature. Boric acid is the worst as well as its weak acidity; Particleboard doesn’t react in phenol even at 180℃and 10% catalyst usage, very low liquefaction efficiency.(3) To analyze the impact of different catalysts and their quantities on Particleboard liquefaction by residue crystallinity, higher residue crystallinity means better catalytic effect in the Particleboard liquefaction reaction, as the same as liquefaction efficiency evaluation in the same liquefaction condition, which based on the quantity of free phenol and residue ratio, the conclusion shows that sulfuric acid is the best catalyst for Particleboard.(4) Comparative ideal liquefaction technological parameters have been selected by the analysis of variance of experimental datum, it shows that, recycled useless Particleboard: liquefaction temperature at 140℃, liquefaction time 1.5 hrs, weight/solvent volume ratio (phenol/Particleboard powder): 4.5. 6% addition of sulfuric acid contributes the residue ratio down to 9.6%, the liquefaction efficiency is 90.4%, and the bromination content in liquefaction product is 43.48%. Lab-synthesized Particleboard: liquefaction temperature at 140℃, liquefaction time 1.5 hrs, weight/solvent volume ratio (phenol/Particleboard powder): 3.5. 6% addition of sulfuric acid contributes to 8.9% residue ratio, the liquefaction efficiency is 91.1%, and the bromination content in liquefaction product is 39.65%.(5) Orthogonal method has been adopted into resinification experiments, according to basic performance tests of resin under national standard and range analysis of resin’s technology indexes, the optimum resinification technology of the two Particleboards has been confirmed. After verification test, two kinds of optimum resinification synthesis technology parameters of the two Particleboard liquefactions have been made. The optimum technology condition of recycled useless Particleboard is: resinification time 2 hrs, temperature at 85℃, the amount-of-substance ratio between formaldehyde and recycled useless Particleboard is 2.1, the amount-of-substance ratio between NaOH and recycled useless Particleboard is 0.6, the amount-of-substance ratio between water and recycled useless Particleboard is 9.0. The optimum technology condition of lab-synthesized Particleboard is: resinification time 2.5hrs, temperature at 90℃, the amount-of-substance ratio between formaldehyde and lab-synthesized Particleboard is 1.8, the amount-of-substance ratio between NaOH and lab-synthesized Particleboard is 0.5, the amount-of-substance ratio between water and lab-synthesized Particleboard is 9.0.(6) To analyze the process from the liquefaction products of the two Particleboards to resin, it is shown that granular wood substance in waste useless Particleboard liquefaction product is bigger than in lab-synthesized Particleboard liquefaction product. Liquefaction resins from the reaction of the two Particleboard liquefaction products and formaldehyde have the content of wood material, which never happens in general synthesis of phenol-formaldehyde resin. To compare the resins themselves, the shape of fibrous substance in waste useless Particleboard liquefaction product is bigger than in lab-synthesized Particleboard liquefaction product.(7) FTIR comparative analysis of the two Particleboard liquefaction resins and general phenol-formaldehyde resin shows that three kinds of resin have the similar absorption peak location, but different strength. The absorption peak locations of the two Particleboard liquefaction resins are higher than phenol-formaldehyde resin; namely, the functional group of the two Particleboard liquefaction resins has higher activity. (8) To compare the 1H-NMR spectrograms of the three resins and their spectrums, lab-synthesized Particleboard liquefaction product and waste useless Particleboard liquefaction product have the big content of lignin units; it shows that in the process of resinification, lignin has joined the copolycondensation reaction. To compare the nuclear magnetic spectrums of the two liquefaction resins, there aren’t many differences, in other words, the resin structures of the two Particleboard liquefaction products are similar, and the differences of the radical content are coming from different chemical components in the two Particleboard liquefaction products.(9) According to compare the 13C-NMR spectrums of the two Particleboard liquefaction resins with general phenol-formaldehyde resin, the two resins contain both o,o Ph-CH-Ph, p,p Ph-CH-P and many lignin units, because in the resin synthesis process, lignin has joined the copolycondensation reaction with phenol and formaldehyde, and the polycondensation of phenol unit itself; there is no free phenol appears in general phenol-formaldehyde resin chemical shifts of free phenol in the other two resins, free phenol hasn’t reacted completely in liquefaction products. To compare the spectrums of the two Particleboard liquefaction resins, there is a little difference; it states that the resin structures of the two Particleboard liquefaction products are similar, but different in the content of radical content.(10) The curing temperature of general phenol-formaldehyde resin is lower than waste useless and lab-synthesized modified phenol-formaldehyde resin; the thermal behavior of phenol resin from waste useless Particleboard liquefaction product is between general phenol-formaldehyde resin and lab-synthesized resin. As the temperature rises from 5℃/min to 20℃/min, the exothermic peak moves toward high temperature gradually and the diversity of the exothermic peak location is getting bigger and bigger, it shows that different test conditions have great impacts on thermal behavior.(11) To compare the one-factor analysis of molding time, molding temperature and the usage of wood powder and the mechanical properties of the liquefaction resin molding material, the optimum liquefaction product molding technology parameter as follow, molding time: 2 hrs, molding temperature: 120℃, the ratio of wood powder and resin: 1:1. To compare ultimate water absorption rate, water absorption thickness expansivity, ultimate volume expansivity and 24hrs water absorption expansivity between liquefaction resin molding material and phenol resin molding material, it is found that the former has better water resistance, the ultimate volume expansivity of waste Particleboard liquefaction resin molding material and lab-synthesized liquefaction resin molding material doesn’t change much, 7.3% and 7.5% respectively; the ultimate water absorption rate are 29.6% and 31.2%; the water absorption thickness expansivity are 4.1% and 3.3%, 24hrs water absorption expansivity are 13.3 and 14.5%.(12) The raw material cost of waste useless Particleboard liquefaction resin is lower about 14.2% than general phenol-formaldehyde resin, which is 695.47 yuan per ton. Even electrical energy and water are needed in the process of waste Particleboard recycling, previous hydro-thermal treatment and liquefaction, the required temperature of resinification and hot press is lower than general phenol-formaldehyde resin, so based on comparative considering, to waste useless Particleboard liquefaction resin has the priority on cost. Furthermore, resource conservation, environment protection, the subsequent social benefit and ecological benefit has profound significance.更多还原