林业工程学报2017，Vol.2Issue(3)：28-32,5.DOI:10.13360/j.issn.2096-1359.2017.03.005
木质素改性脲醛树脂对竹层积材甲醛释放量及胶合性能的影响
Effect of lignin modified urea-formaldehyde resin on the formaldehyde emission and bonding performance of bamboo laminated timber
摘要
Abstract
In order to reduce formaldehyde emission in bamboo laminated timber,the lignin was used as a formaldehyde catching agent to modify urea-formaldehyde (UF) resin,and two-ply bamboo laminated timber was fabricated by using the modified UF-lignin resin with carbonized bamboo strips.The lignin contents and assemble patterns of bamboo strip were analyzed by two-factor analysis method,aiming to investigate the impact of the modified UF-lignin on formaldehyde emission and bonding properties of the bamboo laminated timber.To examine the penetration of the modified UF-lignin resin in the interface,the microscopy of bonding line of the bamboo laminated timber was characterized by the environmental scanning electron microscope (ESEM).The formaldehyde emission of the bamboo laminated timber reduced obviously with the addition of lignin,while different assemble patterns had slight influence on formaldehyde emission.However,all of them reached the E2 level according to GB 18580-2001.The shear strength of bamboo laminated timber increased with the increase in lignin content.The shear strength of the inner-inner pattern (Ⅱ) specimen,the inner-outer (IO) specimen and the inner-inner pattem with node (Node) specimen reached the maximum of 7.6,8.0 and 8.5 MPa,respectively,when the lignin content was 40％,which increased by 85％,70％ and 41％,respectively,compared with those of control groups.The shear strength of inner-inner pattern specimens with nodes was greater than those of the specimens without nodes.ESEM results showed that the bonding interface of carbonized bamboo was compressed or even crushed,the surface cells showed flat pieces in some degrees,and the adhesive was penetrated into damaged cells.It was also observed that there were mainly parenchyma cells on the bamboo surfaces,and the adhesive was occasionally found in the vascular bundle located on the bamboo surfaces,while a little fraction of adhesive may penetrate into the cell in deeper part of bamboo through the slit.The results revealed that the assembly pattern had slight impact on bamboo laminated timber under the same lignin content.With the increase in lignin content,the shear strength of the inner-inner pattern specimen,the inner-outer specimen and the inner-inner pattern with node specimen increased.The shear strength of the inner-outer specimen was generally greater than that of the inner-inner pattern specimen,and the shear strength of inner-inner pattern with node specimen was greater than that of the specimen without node.The ESEM results showed that the carbonized bamboo surface was easy to crush,and the adhesive with high lignin content and high viscosity lacked effective permeability.As a result,the adhesive was concentrated in the crushing cell,the thickening bond line was formed on the bamboo surfaces,and the bonding properties were improved.关键词
木质素/脲醛树脂胶/竹层积材/甲醛释放量/胶合性能Key words
lignin/urea-formaldehyde resin/bamboo laminated timber/formaldehyde emission/bonding performance分类
农业科技引用本文复制引用
刘源松,关明杰,张志威,周文奕..木质素改性脲醛树脂对竹层积材甲醛释放量及胶合性能的影响[J].林业工程学报,2017,2(3):28-32,5.基金项目
江苏省自然科学基金(BK2011822) （BK2011822）
江苏高校优势学科建设工程资助项目(PAPD). （PAPD）
