硼防腐剂与涂料复配处理木材的抗流失性能研究

文章研究了SGB硼防腐剂处理的马尾松试材经环保型水溶性涂料（WAQ）、天然植物油涂料（TRQ）及木材用户外涂料（KJQ）分别处理后的硼流失性能。结果表明硼防腐处理材经涂料再次处理后试件的抗流失性能均有改善,其中效果最好的是TRQ涂料,它与SGB共同处理的试件比单用SGB防腐剂处理的试件硼的抗流失率平均提高了36.5个百分点。     

铜类木材防腐剂抗流失性能的研究进展

铜类木材防腐剂是一种高效低毒型防腐剂,但抗流失性能较差。通过总结归纳木材表面处理、预处理和后处理及添加助剂改善铜类木材防腐剂抗流失性的研究进展,为铜类防腐剂的进一步研究和推广提出建议。     

木竹材防腐技术研究概述

从防腐剂、处理工艺和改性防腐等方面阐述了木竹材防腐的发展现状,分析了木竹材防腐领域目前存在的主要问题,并就今后的重点研究方向进行了展望。木竹材防腐剂仍以含铜化合物为主,同时采取多种方式提高其防腐效果和抗流失性;无机硼盐、有机杀菌剂和天然提取物已成为欧洲多数国家研究和应用的新方向;硼盐防腐剂的抗流失性依然是关注的热点,通过化学改性达到防腐效果已成为新的研究方向。加压处理仍是当前防腐木生产的主要方式。随着竹材开发利用的不断发展,竹材的防腐日益受到重视,出现了针对竹材的防腐剂和处理技术。根据木竹材防腐研究现状,建议木竹材的防腐需重视环境因素,如土壤微生物、光照和水分等对腐朽的加速及防腐剂的影响,并指出加强防腐剂在木竹材中的存在形式和对腐朽菌作用机理的研究,对提高其固着性和抗菌效果具有重要意义。     

六种水溶性复合防腐剂对木材真菌与白蚁的毒性和流失性的研究

国外对水溶性木材防腐剂进行了大量的研究,主要的进展是从容易被水流失、毒性较小的单体防腐剂发展到具有较高毒性、抗流失性的复合防腐剂。水溶性木材防腐剂在国外已经普遍应用~[1],目前我国使用并不普遍。为了满足社会主义建设的需要,结合我国具体情况我们对水溶性复合防腐剂进行了初步研究。试验采用对人畜基本无毒(或低毒)、容易浸注、资源较丰富,并具有防火性能的硼类化合物为主体的防腐剂配方。国内外研究表明,硼类化合物具有一定防腐、防虫效力~[2,3]。本试验为了增进毒效与抗流失性,在配方中增加了铜、铬、锌~[3]。试验还考虑到水溶性防腐剂是否经得起流失严重的冷却塔环境中使用,在这种环境中软腐菌的危害最严重。因此,除对木腐菌作试验外,对软腐菌的毒性与抗流失性也进行了试验。此外,还对白蚁的毒性以及防腐剂对金属铁的腐蚀性进行了试验。本试验以英美等国有关单位提出的铜铬砷与锌铬砷复合剂配方作为对照。     

建筑材用防腐剂配方及其化学性能的试验

我国CCA系列配方与英国CCA(Tanalith C,Celcure K33)的对比试验表明:我国CCA_3、CCA_6配方抗流失和对金属腐蚀效果接近英国产品;砷含量范围低于美国CCA—C型;国产原料配制的CCA_(S)抗流失和对金属腐蚀性较好。浸渍处理试验显示,CCA类防腐剂宜采用加压法。PPA油性防腐剂中的五氯酚溶解度、抗“霜”、油漆性能良好;CCB宜于处理门窗及室内木结构。表层化学浸渍处理可使硼在木材中的保留率提高到60—70%。     

新型木材防腐剂的开发和利用

综述了无机硼类、有机铵类、植物油类以及纳米防腐剂等各类新型木材防腐剂的开发利用现状及研究进展,并针对不同防腐剂的特点,分析了不同类型的木材防腐剂在未来的发展潜力.     

新型水基防腐剂在木材中的固着机理研究进展

对几种主要的水基木材防腐在木材中的固着机理进行了介绍。其中,在胺/氨铜防腐剂体系中,防腐剂中有效成分与木材实质间的反应主要为木质素及半纤维素中的羧基及羟基发生离子交换反应;在微化铜木材防腐剂体系(MCQ/MCA)中,防腐剂中有效成分通过高分子分散剂与木材纤维间较强的附着力固着在处理材中;而在硼类防腐剂体系中,防腐剂中有效成分的固着机理与铜比较相似,但硼酸盐无法直接固着在羧基及羟基中,因此有效成分的固着研究主要涉及以下两个方面:1)增加硼类防腐处理材的疏水性;2)与有机化学物质复合生成稳定的化合物固着在木材中。     

三唑类木材防腐剂研究进展

从制剂的研发、抗菌性能、抗流失性能、对金属腐蚀性能及生物降解性能等方面介绍了三唑类木材防腐剂的研究进展,对其存在的问题及未来的发展潜力进行了探讨。     

CCB木材防腐剂性能改善的研究

ＣＣＢ是一种性能优良的木材防腐剂，但它的抗流失性能不如ＣＣＡ，由于它是水溶性防腐剂，故处理后木材的尺寸亦不稳定。本研究采用在防腐剂中添加聚合物或树脂的方法来提高ＣＣＢ的抗流失性能，使ＣＣＢ处理材的尺寸稳定性大大提高。研究结果表明，在ＣＣＢ中添加少量聚乙烯醇缩醛树脂后，铜、铬、硼的流失与不加树脂相比分别减少５７．６３，７８．５３和９６，４６％；木材湿胀性在弦向减少９１．９７％、径向减少８８．３４％、体积减少８４，２０％；处理材的抗腐力也明显提高。     

CCA 防腐剂在木材中的固着机理

加铬砷酸铜(CCA)作为木材防腐剂在世界范围内已经广泛使用了70余年,目前在我国其仍然是主要的木材防腐剂之一.然而.CCA 中有效成分铬和砷的氧化物所具有的剧毒性,使其在使用过程中流失到外界后会对环境及生物安全造成威胁,而防腐剂中有效成分的流失在很大程度上是由于防腐处理材在使用前防腐剂的有效成分与木材成分之间的固着反应不充分而造成的.对CCA中有效成分在处理材中的固着反应过程、监测方法及反应场所等做了详细介绍,旨在为水基木材防腐剂有效成分在处理材中的固着、流失研究提供借鉴,并为CCA防腐处理材的生产提供理论指导.     

Influence of carboxylic acids on fixation of copper in wood impregnated with copper amine based preservatives

The importance of copper/amine based preservatives is increasing. Leaching of copper from wood preserved with these solutions is still higher than leaching from wood impregnated with copper chromium ones. In order to decrease leaching, different carboxylic acids (octanoic, 2-ethylhexanoic, decanoic) were added to copper/amine/boron aqueous solutions. An experiment of leaching of copper from Norway spruce was performed according to the modified standard procedure (EN 1250). Results confirmed that carboxylic acids significantly improve copper fixation. The best fixation was determined in specimens impregnated with the preservative solutions consisting of copper, ethanolamine, boric acid and octanoic acid. From such wood, only 1.6% of copper was leached.     

水载型木材防腐剂中有效成分固着的影响因素

水载型木材防腐剂在木材防腐市场中占据着主导地位,然而其中的有效成分的抗水流失性差是其存在的主要缺点,这在很大程度上是由于防腐处理材在使用前防腐剂有效成分与木材成分之间的固着反应不充分而造成的,因此提高防腐有效成分在处理材中的固着质量是提高抗流失性的关键.笔者对国内外在水载型防腐剂中有效成分固着方面的研究进行了较为系统、全面的介绍,其中包括木材树种、固着的环境温度与相对湿度、固着时间、木材含水率、防腐剂的保持量、防腐剂成分组成等不同因素的影响,并在此基础上提出了今后的研究方向.     

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。     

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.     

A new boron impregnation technique of wood by vapor boron of boric acid to reduce leaching boron from wood

This study was designed to reveal impregnation ability and to enhance leaching resistance of boron from borate-treated wood. Vapor boron treatment was applied in compressed and uncompressed states at high temperatures such as 180 and 200°C for 6, 8 and 15 min. Following ten-cycle leaching periods, amounts of boron leached from vapor boron treated wood was measured by ion chromatography. According to the results, boric acid can be vaporized under heat and can be impregnated into wood. Success of the technique can be increased by increasing vapor pressure in a closed chamber. Leachability results proved the boron vaporization along with water vapor at various ratios depends on the process variables. These results have importance on dry wood treatment under heat by boron vapor with a little water presence which does not necessitate a further drying process.     

Dimensional stabilization of wood treated with furfuryl alcohol catalysed by borates

Furfuryl alcohol has a sufficiently small molecular size, which allows impregnation into wood and can be polymerized in the cell walls. Polymerization can be accomplished using a catalyst, heat or penetrating radiation. This research illustrates a natural wood polymer composite (NWPC) that was obtained under the catalytic effect of borates. Furfuryl alcohol (FA) and borates were mixed at different ratios before treatment. When borates alone are used, they were totally leached from wood after cyclic leaching periods. However, this was not encountered with the mixture of furfuryl alcohol and borates. Furfuryl alcohol considerably improved antiswelling efficiency by about 85% for both Japanese cedar ( Cryptomeria japonica) and Scots pine ( Pinus sylvestris L.) wood specimens. Results of the leaching tests of borate indicated that boric acid readily lost its boron content in the early cycles of the leaching periods and the highest leaching rate of boron was observed at the first leaching cycle (512 ppm). When furfuryl alcohol mixed with borates, boron was released to the leaching water at slower amounts, suggesting the possibility of longer protection of treated wood in service.     

难溶无机硼酸盐的制备及其硼流失性能

通过复分解反应,制备出难溶于水的无机硼酸盐,并测定其有效成分的质量分数和难溶硼酸盐处理材的硼流失率。结果表明:与硼砂处理材相比,难溶硼酸盐处理材的硼流失率均有不同程度的降低;水溶型制剂处理材的硼流失率在83.2%～96.8%之间,有机溶剂型制剂处理材中,硼的流失率低至2.7%。     

Leaching characteristics of homologues of benzalkonium chloride from wood treated with ammoniacal copper quaternary wood preservative

In Japan, ammoniacal copper quaternary wood preservatives type-1 (ACQ-1), which contains copper and benzalkonium chloride as its active ingredients, is among the most widely used wood preservatives in the pressure treatment of wood. Benzalkonium chloride (BAC) in commercial ACQ-1 products mainly comprises C12 and C14 homologues. In the present study, the leaching characteristics of these BAC homologues were investigated using the heartwood and sapwood portions of Japanese cedar, Japanese larch, and Sakhalin fir treated with ACQ-1 and 1% monoethanolamine (MEA) solution containing equimolar amounts of homologues. Distilled water (DW) and artificial seawater (SW) were used as leaching media. Consequently, it was observed that the leaching rate of the C12 homologue tended to be higher than that of the C14 homologue in DW. The leaching of C12 homologues was accelerated by using SW, resulting in a significantly higher leaching rate than the C14 homologue using SW. It was thought that the difference in the hydrophobicities based on alkyl chain lengths resulted in these phenomena. However, when the heartwood portion of Japanese larch was treated with the homologues in MEA, the leaching rate of the C14 homologue was significantly higher than that of the C12 homologue.