木素-UF胶粘剂的研制

本文介绍了一种木素－UF胶粘剂的制造方法，并分析了木素羟甲基化、过程pH值、尿素加料次数及木素加量对胶粘剂性能的影响。     

基于木素填料的脲醛树脂胶粘剂研究

研究了面粉、碱木素和木素磺酸钙对脲醛树脂(UF)胶粘剂性能的影响,探讨了碱木素、木素磺酸钙用作胶粘剂填料的可行性。研究结果表明:UF胶粘剂的固含量随着填料用量的增加而增大;UF胶粘剂的固化时间和pH值随面粉或木素磺酸钙用量的增加而降低,却随碱木素用量的增加而增大;使用含木素填料的UF胶粘剂压制胶合板,当w(木素)=15%～20%、施胶量为240～260g/m2时,胶合板的湿态胶合强度略高于纯UF胶粘剂压制的胶合板;以m(面粉)∶m(木素)=1∶1作为混合填料,其干态胶合强度远高于国家标准,并且均高于1.05MPa,其湿态胶合强度能达到国际标准。     

木素—苯酚胶粘剂制造方法

以牛皮纸浆黑液直接作为原料,可以获得工作性能、贮藏稳定性、粘附性能良好的木素—苯酚缩聚树脂胶粘剂,该胶粘剂便宜、无味,而且可以用于制造耐水性的胶合板。关于木素—苯酚树脂胶粘剂也在“木材工业”Vol.24-2中由半井等人的研究论文中阐明了它的那种胶粘剂的利用价值,然     

生物基木材胶粘剂

具体介绍了几种重要生物基木材胶粘剂,包括木素、单宁、大豆蛋白、淀粉、木质生物质液化产物胶粘剂、热解生物油胶粘剂等的研究进展情况。分析了生物基木材胶粘剂的应用现状,指出了生物基木材胶粘剂存在的问题,并对其发展方向进行了展望。     

天然可再生资源在木材胶粘剂中的应用

综述了木素、单宁、大豆蛋白、淀粉、壳聚糖等天然可再生资源在木材胶粘剂中的应用。     

尿素胶粘剂改良增量剂

众所周知,从牛皮纸浆或亚硫酸盐纸浆蒸解废液中获得的各种木素物质,可以用来作为苯酚胶粘剂或尿素胶粘剂的增量剂。然而,从半化学纸浆的蒸解废液中获得的木素物质或将其变性物用来作尿素胶粘剂的增量剂都未见报道,因为尿素胶粘剂价格便宜,并且一向使用价格非常便宜的小麦粉或血粉     

木素基酚醛树脂胶粘剂的应用性能研究

采用热化学酚化技术活化木素得到木素酚化产物,以酚化产物代替苯酚制备低成本的木素酚化液基酚醛树脂(LPF)胶粘剂。采用红外光谱(FT-IR)对LPF和传统PF的结构进行了表征,通过对比试验分析了LPF的应用性能,并对LPF胶粘剂应用性能产生的机理作了一定的探讨。结果表明:酚化后的木素参与了LPF胶粘剂的合成,并具有新的不同取代基的苯环结构;LPF胶粘剂与传统酚醛树脂(PF)胶粘剂具有相似的应用性能,前者比后者具有更低的游离酚(醛)含量(游离酚<0.12%,游离醛<0.08%)、更快的干燥速率和更低的施胶量(固含量29%时施胶量为297g/m2);另外,LPF胶粘剂具有优异的胶合性能(达到了Ⅰ类胶合板的标准要求)和储存稳定性,完全满足高性能环保型胶粘剂的使用要求。     

胶粘剂新专利

聚糖基水凝胶胶粘剂;带防粘衬层的压敏胶片材;胶粘材料及其在木素纤维素复合材料制品中的应用;胶粘带及其应用;高含量苯乙烯的SBS热熔型胶粘剂;加成固化型硅橡胶用双组分胶粘剂;胶粘剂用丙烯共聚物.     

利用SSL制木素胶粘剂回顾

本文综述了用SSL制作木素胶粘剂的研究历史和现状，并介绍其制胶原理和利用方法。     

木素酚醛胶的制造方法

日本公开昭60-22024介绍了一种苯酚-木素-甲醛系胶粘剂的制造方法。该胶粘剂中木素含量为苯酚量的10～50％,这种木素是将pH调至4～10的亚硫酸纸浆废液(SSL),在140～180℃用氧或空气氧化到pH为3～6得到的物质(以下称作改性木素磺酸盐)。改性木素磺酸盐的添加,可使胶粘剂的胶粘性能提高。本专利的特点是解决了苯酚系胶粘剂胶粘性能低的缺点。在本专利中,SSL是针叶材或阔叶材,针叶材最佳。作为SSL的碱用Na、Ca、Mg、NH_4均可,但用碱的情况下,在氧化反应时有淤渣产生,Na或Mg碱较好。反应温度160～180℃最佳。经氧化反应得到的改性木素磺酸盐,在苯酚与甲醛反应时加入,然后进行共缩合反应,或在经过预反应得到的酚醛初期缩合物中混合,以得到苯酚-甲醛-木素系胶粘剂。该胶粘     

木质素在胶粘剂中的应用研究进展

介绍了木质素的结构、分类与性能以及改性方法,综述了木质素在酚醛树脂胶粘剂、脲醛树脂胶粘剂、三聚氰胺甲醛树脂胶粘剂、环氧树脂胶粘剂以及聚氨酯胶粘剂中的应用研究进展,并对今后的研究方向作了展望。     

In situ synthesis of novel biomass lignin/silica based epoxy resin adhesive from renewable resources at different pHs

Novel biomass lignin/silica composites were prepared and isolated from rice husk renewable resources at different pHs. Selective precipitation was achieved by decreasing the solution pH from 9.5 to 1.5. When pH reached 3.5, the ratio of lignin and silica mostly achieved the maximum of 1:1. We selected lignin/silica composites as reactants to replace 20?wt% bisphenol A in preparing epoxy resin. The cured novel biomass function lignin/silica-based epoxy resin adhesive showed the highest adhesive strength up to 2.68?MPa, which displayed 123% of neat epoxy resin adhesive. In addition, lignin/silica composites were depolymerized through the hydrothermal method by NaOH as a catalyst, which was used as reactants to replace 35?wt% bisphenol A in the process of in situ synthesis of epoxy resin adhesive. At this point, the high epoxy value (1.42?wt%) and large adhesive strength (3.98?MPa) of lignin/silica-based epoxy resin adhesive were obtained, which adhesive strength was 183% of neat epoxy resin adhesive. The results demonstrated that depolymerized lignin/silica-based epoxy resin adhesive showed the higher epoxy value and the adhesive strength compared with neat epoxy resin adhesive and lignin/silica-based epoxy resin adhesive. Their function in epoxy matrix resulted in better processability.     

木质素基木材胶粘剂的研究进展和应用现状

木质素胶粘剂是胶粘剂"绿色化学"的一个重要发展方向,论述了国内外木质素在木材胶粘剂中的制备和应用进展,为木质素胶粘剂的广泛应用和新用途的开发提供依据。     

Development and characterization of a lignin–phenol–formaldehyde wood adhesive using coffee bean shell

In the present study, the possibility of development of a wood adhesive using coffee bean shell lignin (Cbsl) has been explored. Cbsl-modified phenolic adhesive has been prepared by replacing phenol with lignin at different weight percents. The optimization of weight percent lignin incorporation was carried out with respect to mechanical properties. It was found that up to 50 wt% of phenol could be replaced by Cbsl to give lignin–phenol–formaldehyde adhesive (LPF) with improved bond strength in comparison to control phenol–formaldehyde (CPF). Optimized LPF and CPF adhesives were characterized by IR, DSC and TGA. The IR spectrum of LPF showed structural similarity to CPF. Thermal stability of LPF adhesive was found to be lower as compared to that of CPF. DSC studies revealed a higher rate of curing in the LPF adhesive.     

木质素酚醛树脂胶粘剂黏度的研究

木质素胶粘剂高黏度的特征阻碍了其工业化应用,该文考察了木质素酚醛树脂(LPF)胶粘剂的pH、质量分数、氯化钠与尿素的加入、贮存时间等因素对其黏度的影响,作为对比,同时测试了这些因素对酚醛树脂胶粘剂和麦草碱木素(WSSL)碱性溶液黏度的影响。结果表明,LPF胶粘剂的黏度随着尿素的加入降低,而随着其质量分数的增加、pH的降低、氯化钠的加入急剧升高,并分别在w(LPF)=30.0%、pH=10.2、w(NaCl)=8.3%处有一个转折点;LPF胶粘剂的黏度曲线与WSSL碱性溶液相似,而与酚醛树脂胶粘剂相差较大;要制得高含量的LPF胶粘剂,其pH应大于10.2,w(NaCl)<8.3%,并且w(尿素)=2%～3%。     

木质素在人造板胶黏剂中的应用

综述了木质素在酚醛树脂、脲醛树脂、三聚氰胺甲醛树脂3种人造板胶黏剂中的应用进展，指出了利用无毒、稳定、价廉、可再生的木质素代替不可再生且有毒的苯酚、甲醛制取工业用人造板胶黏剂是木材用胶黏剂领域的重要研究方向。     

胺化改性木质素合成聚氨酯胶粘剂的研究

采用Mannich法对纯化木质素进行胺化改性,以提高其活泼氢数量和木质素的反应活性;然后以此作为部分聚乙二醇的替代物,将其与异氰酸酯反应合成PU(聚氨酯)胶粘剂。结果表明:胺化木质素中引入的氮含量约为2.64%,说明木质素的活性明显提高;当w(胺化木质素)=25%时,相应PU胶粘剂的湿胶接强度(1.53 MPa)达到GB/T 9846—2004标准中Ⅰ类胶合板的指标要求,并且其热稳定性能得以明显提高;胺化木质素可以取代部分聚乙二醇,其含量对胶粘剂的力学性能和热稳定性能影响显著。     

Epoxy-lignin polyblends: effects of various components on adhesive properties

Polyblends based on different epoxy pre-polymers, various lignins, and some additives such as fillers or a third polymer were prepared at room temperature and thermally cured. The effects of the different components, such as epoxy pre-polymer, hardener, lignin type, lignin molecular weight, filler, and a third polymer, on the adhesive properties of the polyblends were studied. The adhesive properties of the epoxy-lignin (EP-L) polyblends as determined by shear strength testing (by tension loading) correlated well with the type of lignin (i.e. hardwood or softwood) and lignin molecular weight. A variety of epoxy-hardener systems with lignin (up to 20%, in some cases) resulted in an improvement in their adhesive joint shear strength. The improvements varied from 112% to 178% of the control epoxy for different epoxy-hardener systems. The adhesive joint shear strength of EP-L was not much affected by the addition of 20% by weight of mineral fillers. The presence of a third polymeric component such as poly(vinyl chloride) (PVC) or phenoxy resin had a beneficial effect on the adhesive properties of the EP-L polyblends. This work demonstrates that a wide variety of commercial lignins, epoxy pre-polymers, hardeners, mineral fillers, and third polymeric components can be employed in EP-L polyblends with an improvement in the adhesive properties and a cost advantage.