新型木材防腐剂的开发和利用(续)

新型有机铵类木材防腐剂 有机铵类木材防腐剂从研究和应用上来说并不算新型的木材防腐剂.早在1976年,Butcher等[11]就采用季铵盐类化合物涂饰木材表面以达到防腐的目的.而且在1978年新西兰就已经正式将DDAC(二癸基二甲基氯化铵)和BAC(十二烷基二甲基苄基氯化铵)作为商用木材防腐剂广泛使用.但不久研究者却发现,有机铵类化合物虽然在实验室的实验中对木腐菌、变色菌、霉菌和白蚁等的抵抗力都较好,但处理材在野外耐腐试验和实际应用时对以上破坏木材的微生物的抵抗力却很低,基本不能起到预期的防腐效果.因此在此后很长一段时期内,有机铵盐类木材防腐剂的研究和应用进展缓慢.尽管如此,有机铵类及其衍生物类所具有的耐腐广谱高效性、低毒环保性、在木材中固着率高、对木材表面污染小以及原料来源广等优点使其具有很好的应用和发展前景.尤其是近几年来,随着环境问题的突出,CCA等含重金属的木材防腐剂被禁用或限用,行业内重新将注意力转向拥有诸多优点的有机铵类化合物的研究和应用上.     

含氢化诺卜基的季铵盐类化合物对松枯梢病原菌的抑制作用及其机理研究

测试了由β-蒎烯为起始原料合成得到的3个系列共36种含氢化诺卜基的季铵盐类化合物对松枯梢病原菌抑制率,并从松枯梢病菌菌丝干质量、细胞膜通透性及菌丝结构等3个方面,初步探究了双氢化诺卜基二甲基溴化铵(14)、六亚甲基-1,6-双(氢化诺卜基二甲基氯化铵)(26)、四亚甲基-1,4-双(氢化诺卜基二乙基溴化铵)(28)与1,4-二苄基-双(氢化诺卜基二甲基溴化铵)(31)等4个化合物对松枯梢病原菌的抑菌机理。研究结果表明：大部分含氢化诺卜基的季铵盐类化合物对松枯梢病菌均有良好的抑制作用,且含有双氢化诺卜基的双子季铵盐对松枯梢病菌的抑制作用强于单季铵盐,多数含有双氢化诺卜基的季铵盐类化合物在质量浓度50 mg/L下的抑制率均达90%以上,甚至高达100%,抑制效果大大超过常用杀菌剂百菌清和多菌灵。初步的抑菌机理研究发现：4种化合物处理后松枯梢病菌的菌丝干质量减少,细胞膜通透性增加,相对电导率明显升高,菌丝体形态和结构发生明显变化。推测季铵盐类化合物可通过破坏病菌细胞膜的完整性和改变菌丝体形态与细胞结构来抑制松枯梢病菌的菌丝生长。     

紫外-可见分光光度法测定木材防腐剂中有效成分含量

Cu(Ⅱ)、Cr(Ⅵ)、As(Ⅴ)、季铵盐在一定条件下加入显色剂后生成的物质可对光选择性吸收,通过紫外-可见分光光度法测定络合物的吸光度实现对有效成分含量的测定。采用紫外-可见分光光度法测定木材防腐剂CCA(加铬砷酸铜)和ACQ(氨/胺溶季铵铜)木材防腐剂中铜、铬、砷和季铵盐的含量。结果表明:此法重复性和准确性良好,相对标准偏差均在2%之内,加标回收率为95%~105%,与化学分析法比较,相对偏差在-5%~5%之内,准确度高,简便易行,可用于大批试样的分析。     

超声波萃取ACQ防腐处理材中季胺盐的研究

采用自动电位滴定仪测定方法,考察了不同萃取条件对超声波萃取ACQ防腐处理材中季胺盐(以二癸基二甲基氯化铵为例)含量结果的影响,并探讨了木粉颗粒度、萃取时间、萃取温度和萃取剂的用量等因素对萃取防腐处理木材中季胺盐的影响.结果表明:超声波萃取ACQ防腐处理材中的季胺盐时,最佳木粉颗粒为60目,萃取体系的最佳温度为35℃,最佳萃取时间为3h,提取液的质量与木粉质量的最佳比值为20.     

折断木用防腐剂处理后的雨水模拟试验

用硫酸铜与二癸基二甲基氯化铵（DDAC）复配,对折断木进行顶端施药,模拟1～3年降雨量雨水对药剂主要活性成分流失的影响,检测木材中主要活性成份的载药量。结果表明：随取样深度增大,试样总载药量、DDAC与铜的含量都呈下降趋势;降雨量对试样中铜含量、DDAC含量、总载药量变化影响不显著。经5%浓度的防腐剂施药使腐朽菌不能在木材顶端1 cm内生长,并在2～3 cm范围内减缓生长,在木材顶端形成防护层,可在3年以上时间内避免和减缓腐朽的发生,有效减少林农损失。5%药剂总成本约1元/株。     

三种铜-季铵盐防腐剂的抗流失性及对木材材色的影响

研究了3种季铵盐与铜复配后的防腐剂的抗流失性和对木材材色的影响。结果表明：3种防腐剂均在较低温度下后续固着效果较好。后续固着温度为15℃，处理药液浓度为0.5%的条件下，FFJ－2的固着效果最好。但处理后对材色的影响较大。     

靖远松叶蜂对松叶蜂醇丙酸酯的林间反应

靖远松叶蜂雄蜂对其它松叶蜂性信息素的进一步林间反应表明：（２Ｓ，３Ｒ，７Ｒ）－３，７－二甲基－２－十三碳醇（松叶蜂醇）丙酸酯和（２Ｓ，３Ｒ，７Ｓ）－二甲基－２－十三碳醇（松叶蜂醇）丙酸酯的混合物对雄蜂的引诱作用最强。因此认为，松叶蜂醇丙酸酯的这两种异构体很可能是靖远松叶蜂性信息素的主要组分，可应用于种群监测等。     

季铵盐类化合物(QAC)在木材防腐中的应用

主要综述了季铵盐类化合物(QAC)在用作木材防腐剂时的耐腐性、抗流失性及其与木材的结合机理等方面的研究概况,分析了实验室耐腐性和野外实验耐腐性结果不一致的原因。此外也介绍了对季铵盐进行改性处理方面的一些研究进展。     

氢化诺卜基二甲基烷基卤化铵的合成及抑菌活性

由氢化诺卜基二甲基胺与9种卤代烃反应制得含氢化诺卜基的季铵盐化合物(氢化诺卜基二甲基烷基卤化铵),分别为氢化诺卜基二甲基乙基溴化铵(2a)、氢化诺卜基二甲基正丙基溴化铵(2b)、氢化诺卜基二甲基正丁基溴化铵(2c)、氢化诺卜基二甲基正戊基溴化铵(2d)、氢化诺卜基二甲基苄基溴化铵(2e)、氢化诺卜基二甲基苄基氯化铵(2f)、氢化诺卜基二甲基乙基碘化铵(2g)、氢化诺卜基二甲基正丙基碘化铵(2h)、氢化诺卜基二甲基正丁基碘化铵(2i)。采用红外光谱和核磁共振表征了它们的结构,并用菌丝生长速率法测试了9种化合物对8种植物病原真菌的抑制效果,结果表明:在药液质量浓度为500 mg/L下,9种化合物对8种供试病原菌均具有一定的抑制效果,其中2d的抑菌效果最好,对层出镰刀菌、梨链格孢菌、辣椒菌核病菌、毛竹枯梢病菌、松枯梢病菌的抑菌率均达到100%,2b、2c和2f也具有优异的抑菌性能,对辣椒菌核病菌的抑菌率均达到100%。     

戊二醛交联木质素季铵盐-尿素颗粒的制备及其缓释性能的研究

为了探究木质素季铵盐包埋尿素的优化制备条件及其在缓释肥生产中的应用,以三甲基木质素季铵盐(L-QA)为原料,Span 80为分散剂,戊二醛为交联剂,采用反相悬浮法制备了戊二醛交联木质素季铵盐-尿素(GCL-QA-U)颗粒,通过FT-IR表征了其结构,探讨了不同条件对尿素包埋率的影响,以得到最佳制备工艺条件及产品,再利用水溶试验法和土柱试验法测定其缓释性能。结果表明:FT-IR分析表明L-QA中含有季铵根结构,初步认定尿素被包埋在L-QA中;L-QA含氮量为1.98%,GCL-QA-U含氮量为2.88%。GCL-QA-U颗粒制备最佳工艺条件在10 m L L-QA溶液中,戊二醛用量4 m L、反应时间2 h、转速200 r/min和Span 80用量1.0 m L,其最大尿素包埋率为41.61%;水溶试验(肥水比例1∶20)和土柱淋溶试验证明GCL-QA-U颗粒24 h尿素累积释放率分别为5%和3.86%,28天尿素累积释放率分别为79.47%和74.80%,符合缓释肥料GB/T 23348—2009的标准。     

Biological effectiveness of didecyl dimethyl ammonium tetrafluoroborate (DBF) against basidiomycetes following preconditioning in soil bed tests

Evaluation of wood preservatives in soil-contact tests is becoming an important issue since detoxification of wood-protecting compounds by fungi and bacteria found in soil may decrease the resistance of treated wood. In this study, the decay resistance of wood treated with didecyl dimethyl ammonium tetrafluoroborate (DBF), a recently developed quaternary ammonia compound, was evaluated in both soil bed and laboratory decay resistance tests. Small specimens (5×10×100 mm³) of DBF-treated and untreated sugi sapwood were subjected to decay in laboratory soil bed tests (DIN ENV 807 (2001)) followed by Basidiomycetes tests (DIN EN 113 (1996)). Exposure in field soil and compost soil substrates was used to observe the effects of wood degrading and other soil-inhabiting micro-organisms on the decay resistance of the specimens. Soil bed tests showed that DBF-treated wood specimens at 7.7 kg/m³ retention level (1% DBF solution concentration) showed better performance compared to 0.01 and 0.1% DBF treatments. The 7.7 kg/m³ retention level was also effective to protect the wood specimens against Coniophora puteana and Coriolus versicolor in Basidiomycetes tests. It is concluded that detoxification of wood preservatives in soil contact is an important factor to determine protective properties of treated wood in ground contact applications. Further experiments with larger specimens are needed to observe the performance of DBF-treated wood at higher retention levels in field above ground and ground contact tests. Dedicated to Prof. Dr. H.C. Mult. Walter Liese on the occasion of his 80th birthday.     

Biodegradation of new quaternary ammonium compounds in treated wood by mould fungi

The degradation of seven potential wood preservatives based on imidazolium compounds (ICs) and quaternary ammonium compounds (QACs) with a modified anion structure by mould fungi was determined using soil-block method. Experiments were carried out on Scots pine (Pinus sylvestris L.) wood. Two-phase titration and high-performance liquid chromatography (HPLC) method were used to detect and quantify the degradation products. The performed soil-block tests showed that the ICs and QACs with alkoxymethyl substituents were leached from the experimental wood when in contact with moist soil and revealed their fungal detoxification by mould fungi, especially by Gliocladium roseum. The degree of biological decomposition of new compounds was higher than didecyldimethylammonium chloride and didecylmethylpoli(oxyethyl)ammonium propionate. The observations of the colonization by mould fungi were made using the scanning electron microscope (SEM). Decay of treated wood by mould fungi showed its tolerance to QACs.     

室内木地板及木制品防腐、防虫药剂筛选

本文对木质地板及木制品适用的防腐、防虫药剂进行了筛选研究，初步结果表明：季铵盐类、拟除虫菊酯类复合型药剂具有高效、低毒的特性。符合室内装修的特殊环保要求，为确定居室用木质地板及木制品防腐、防虫药剂及相关标准的制定提供了依据。     

Efficacy of wood preservatives formulated from okara with copper and/or boron salts

As a substitute for high-cost copper azole (CuAz) and alkaline copper quaternary (ACQ) wood preservatives, alternative wood preservatives were formulated with okara, which is an organic waste from the production of tofu, and copper chloride and/or borax. Each preservative was used in treatment of wood blocks in a reduced-pressure method to measure its treatability. The treated wood blocks were placed in hot water for 3 days to examine the stability of the preservatives against hot-water leaching. The preservatives successfully penetrated into wood blocks, probably due to the use of ammonium hydroxide as a dissociating agent. However, the stability of okara-based preservatives dropped as the concentration of acid in the solutions used for hydrolysis of okara increased. The treatability and leachability of the preservatives were not affected by hydrolysis temperature but were negatively affected by the addition of borax. Leached wood blocks treated with okara-based preservatives and exposed to decay fungi Gloeophyllum trabeum and Postia placenta over 12 weeks showed good decay resistance. Okara-based wood preservatives can protect wood against fungal attack as effectively as CuAz, and have potential for use as environmentally friendly wood preservatives.     

邓恩桉木材物理性质的研究

对广西沙塘林场22年生邓恩桉木材的主要物理性质进行测定和分析。结果表明：邓恩桉木材气干密度、全干密度分别为0.751、0.707 g＆#183;cm-3;其径向、弦向和体积湿胀率分别为3.8%、4.7%、8.9%;径向、弦向和体积干缩率分别为3.9%、10.0%、13.8%;192 h的吸水率为83.5%。除木材密度外,邓恩桉木材的主要物理指标处于国产阔叶树材的中下水平,对其进行改性处理后可作为轻型建筑和家具用材。     

Spectrophotometric assay of a wood preservative, <Emphasis Type="Italic">N,N</Emphasis>-didecyl-<Emphasis Type="Italic">N</Emphasis>-methylpoly(oxyethyl) ammonium propionate (DMPAP), in aqueous solution

A spectrophotometric assay based on the color reaction between N,N-didecyl-N-methyl-poly(oxyethyl) ammonium propionate (DMPAP) and 4-[4-(dipropylamino) phenylazo]-benzenesulfonic acid (propyl orange) was used to determine DMPAP concentrations as a wood preservative. The assay was carried out using a propyl orange solution at pH 2.9. The visible absorption spectrum of propyl orange showed an absorption maximum at 510 nm, which decreased linearly with increasing DMPAP concentration from 0 to 10 ppm. To apply this assay method to determine DMPAP retention in treated wood, the influence of wood extractives on the assay was investigated. Extractives from Japanese cedar, hinoki cypress, and Japanese larch were found to increase apparent DMPAP concentration. However, it was also found that measuring visible absorption at 477 nm prevented overestimation and gave precise values. This assay can be a viable alternative to the current methods for the determination of DMPAP concentrations.     

Antimicrobial activity of Evodia elleryana.

The methanol extracts of Evodia elleryana, leaves, stem wood, stem bark, root wood and root bark were partitioned (petrol, dichloromethane, ethyl acetate). All obtained fractions showed a broad spectrum of antibacterial activity, while none were active against tested moulds.     

Micromorphology,moisture sorption and mechanical properties of a biocomposite based on acetylated wood particles and cellulose ester

Abstract

One of the major issues in a long-term perspective for the use of wood–plastic composites (WPCs) in outdoor applications is the moisture sensitivity of the wood component and the consequent dimensional instability and susceptibility to biological degradation of the composite. In this work, the effects of using an acetylated wood component and a cellulose ester as matrix on the micromorphology, mechanical performance and moisture uptake of injection-moulded WPCs have been studied. Composites based on unmodified and acetylated wood particles, specially designed with a length-to-width ratio of about 5–7, combined with both cellulose acetate propionate (CAP) and polypropylene (PP) matrices were studied. The size and shape of the wood particles were studied before and after the processing using light microscopy, and the micromorphology of the composites was studied using a newly developed surface preparation technique based on ultraviolet laser irradiation combined with low-vacuum scanning electron microscopy (LV-SEM). The water vapour sorption in the composites and the effect of accelerated weathering were measured using thin samples which were allowed to reach equilibrium moisture content (EMC). The length-to-diameter ratio was only slightly decreased for the acetylated particles after compounding and injection moulding, although both the unmodified and the acetylated particles were smaller in size after the processing steps. The tensile strength was about 40% higher for the composite based on acetylated wood than for the composite with unmodified wood using either CAP or PP as matrix, whereas the notched impact strength of the composite based on acetylated wood was about 20% lower than those of the corresponding unmodified composites. The sorption experiments showed that the EMC was 50% lower in the composites with an acetylated wood component than in the composites with an unmodified wood component. The choice of matrix material strongly affected the moisture absorptivity of the WPC. The composites with CAP as matrix gained moisture more rapidly than the composites with PP as matrix. It was also found that accelerated ageing in a Weather-Ometer® significantly increased the moisture sensitivity of the PP-based composites.     

提高杨木线性振动摩擦焊接胶合性能的研究

研究了杨木线性振动摩擦焊接的干剪切强度、湿剪切强度和木破率。为提高杨木摩擦焊接的湿剪切强度与木破率,采用表面氧化、表面磺化以及表面涂覆的方式处理杨木板材,再经线性振动摩擦焊接进行黏合,使用万能力学试验机测得其剪切强度,对比表面处理前后剪切强度的变化,并利用傅里叶红外光谱分析了其表面处理前后基材和摩擦焊接层的化学基团变化情况,对胶合性能的变化做出解释。研究结果表明:杨木经过表面氧化磺化涂覆醋酸锌处理后,摩擦焊接层的干剪切强度为5.41 MPa,木破率为63%,与未处理的杨木相比,分别提高了48.22%和96.88%;湿剪切强度从0提高到1.34 MPa;摩擦焊接时厚度损失减少了46.4%。杨木分别经过表面氧化和表面磺化处理后,摩擦焊接层的干剪切强度仅为3.45和4.10 MPa,木破率为28%和42%,湿剪切强度为0.76和0.96 MPa。摩擦焊接层的红外光谱分析表明,经表面氧化磺化涂覆醋酸锌处理后,杨木中的纤维素和半纤维素分解,使木质素的相对含量有所增加,且活化了杨木中的—OH,与醋酸锌生成多醚,消耗了亲水性的—OH。     

The reflectance method for testing the effectiveness of fungicides against surface mould growth on materials: I. Wood

Summary An instrumental method for the measurement of the toxic value of preservatives against mould fungi on wood and wood products was tested as an alternative to the widely used visual method with its inherent disadvantage of subjectivity. The new criterion of effectiveness to be used was light reflectance as measured by either the Zeiss photometer (Leukometer) or the Zeiss spectrophotometer (Spekol 10) fitted with the Rd/0 reflectance adapter. Sodium pentachlorophenate and the WR-3 (quaternary ammonium compound), applied to pine and birch wood samples were tested for effectiveness against five species of fungi capable of causing surface moulding. Although the reflectance method was more laborious, the results obtained seem to be better than those obtained by the visual method. The proposed method appears to be of practical value in eliminating difficulties involved in the subjective assessment of both the intensity of surface growth and the effectiveness of the wood preservatives themselves.Paper sponsored by the State Enterprise of Conservation of Fine Arts Objects, Warszawa ul. Zielna 3The authors thank Dr. J. D. Thornton, CSIRO Division of Forestry and Forest Products, Highett, Australia, for kindly correcting the English text of this paper