title: Hydrothermal degradation of lignin: products analysis for phenol formaldehyde adhesive synthesis.
abstract: Corncob lignin was treated with pressurized hot water in a cylindrical autoclave in current investigation. With the aim of investigating the effect of reaction temperature and retention time on the distribution of degradation products, the products were divided into five fractions including gas, volatile organic compounds, water-soluble oil, heavy oil, and solid residue. It was found that hydrothermal degradation of corncob lignin in pressurized hot water produced a large amount of phenolic compounds with lower molecular weight than the raw lignin. Some phenolic and benzene derivatives monomers such as vanillin, 2-methoxy-phenol, 2-ethyl-phenol, p-xylene, and 1, 3-dimethyl-benzene were also identified in the degradation products. The products were further analyzed by GC-MS, GPC, 2D-HSQC, and (31)P-NMR to investigate their suitability for partial incorporation into phenol formaldehyde adhesive as a substitution of phenol. The results indicated that the reaction temperature had more effect on the products distribution than the retention time. The optimal condition for heavy oil production appeared at 290 °C with retention time 0 min. The compounds of heavy oil had more active sites than the raw lignin, suggesting that the heavy oil obtained from hydrothermal degradation of lignin is a promising material for phenol formaldehyde adhesive synthesis.
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, 100083 Beijing, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yang
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, 100083 Beijing, China. Electronic address: ytq581234@bjfu.edu.cn.
authors.forename: Tong-Qi
authors.initials: TQ
authors.lastname: Yuan
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, 100083 Beijing, China.
authors.forename: Ming-Fei
authors.initials: MF
authors.lastname: Li
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, 100083 Beijing, China. Electronic address: rcsun3@bjfu.edu.cn.
authors.forename: Run-Cang
authors.initials: RC
authors.lastname: Sun
mesh_terms: D000269:Adhesives / Q000138:chemical synthesis*; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D005557:Formaldehyde / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D008031:Lignin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009821:Oils / Q000032:analysis; D019800:Phenol / Q000032:analysis*; D012995:Solubility; D013696:Temperature; D013997:Time Factors; D055549:Volatile Organic Compounds / Q000032:analysis; D014867:Water / Q000737:chemistry*
chemical_list: D000269:Adhesives; D009821:Oils; D055549:Volatile Organic Compounds; D014867:Water; D005557:Formaldehyde; D019800:Phenol; D008031:Lignin
keywords: (31)P-NMR; 2D-HSQC; Degradation; Lignin; Phenol formaldehyde adhesive; Pressurized hot water