微囊型甲醛捕捉剂对薄木饰面人造板甲醛释放量的影响

随着薄木饰面板在家具、装修领域中的使用量越来越大,人造板的游离甲醛释放问题也愈发引起人们关注,现有的甲醛捕捉剂一般只能在短期内发挥效果,而对人造板甲醛的长期释放控制效果并不理想。为解决人造板甲醛释放的长期性问题,以尿素为芯材、乙基纤维素为壁材制备微囊型甲醛捕捉剂,探讨不同乳化剂及芯壁比制备的微囊型甲醛捕捉剂对饰面人造板甲醛控释效果的影响。结果表明,当乳化剂为十二烷基硫酸钠、芯壁比为3∶1,乳化剂用量1%、壁材质量分数3%、搅拌速度1000 r/min时,制备出的微胶囊芯材负载效果最好,负载量达到36.24%、负载效率为8.05%。采用该微胶囊以2%的质量比与脲醛树脂胶黏剂混配进行饰面板贴面热压时,得到的薄木贴面板的甲醛释放量相比未处理饰面板降低了37.9%。经过20 d后,微胶囊对其饰面板甲醛的释放仍表现出一定的控制效果,饰面板的甲醛释放量为0.99 mg/L,仅为未处理饰面板的56.9%。说明用微囊型甲醛捕捉剂对饰面人造板进行处理不仅能够对饰面板中的甲醛进行控释,而且在长期的放置、使用过程中也能够持续发挥作用,从而达到降低室内空气中甲醛浓度的目的。

Effect of microencapsulation of formaldehyde capture agents on formaldehyde emission from veneered panels

Recently,with the continuous improvement of living quality,people pay more attention on indoor decorations.Wood-based panels are widely used in the field of indoor decoration and furniture manufacturing because of their good nature characteristics and appearances.Because most wood-based panels are bonded using urea-formaldehyde resin that causes formaldehyde emission from the panels,which limits their application in the indoor environment.Due to the incomplete curing of adhesives during hot pressing,the free formaldehyde would migrate and release from inner to surface.In addition,the degradation of wood composites also produces a small amount of formaldehyde.Formaldehyde has been identified as the typical hazardous composite that causes cancer and birth defects by the world health organization.Formaldehyde is generally released slowly from the source,and new products release the greatest amount of formaldehyde in the first few months.In order to control the continuous release of formaldehyde in long term,the formaldehyde trapping agent is used during the production and in the final product.However,formaldehyde capture agents can only work in a short term.In order to reduce the potential harm of formaldehyde to human health,it is necessary to control the long-term release of formaldehyde.In this study,formaldehyde capture microcapsules with urea as a core material and ethyl cellulose as a wall material were developed and the influences of the emulsifier and wall material ratio on the formaldehyde emissions from veneered panels were investigated.The results showed that the microcapsules with the optimal morphology and high degradation efficiency could be obtained under the conditions of 1%sodium dodecyl sulfate emulsifier,3%shell liquid,3∶1 core-shell ratio and 1000 r/min stirring speed.The loading rate and efficiency of microcapsules reached 36.24%and 8.05%,respectively.The formaldehyde emission of microcapsule veneer was 37.9% lower than that of the control group.After exposure for 20 d,the formaldehyde emission of the tablets was still low,with the formaldehyde mass concentration of 0.99 mg/L,which was 56.9%of the control group.The microencapsulated formaldehyde trap can effectively control the short-term and long-term formaldehyde release of the panel and play an important role in the control of indoor air emission.By capturing formaldehyde for a long time,the microcapsules can effectively reduce the indoor formaldehyde content and keep the indoor formaldehyde content at a low value for a long time,to effectively prevent formaldehyde from affecting human health and maintain good indoor air quality.