Open Access

ARTICLE

Preparation and Characterization of Phenolic Prepolymer Impregnated Chinese Fir by Cyclic Increasing-Pressure Method with Green and Efficient

Yuan Zhang¹, Ping Li¹, Yiqiang Wu^1,2, Guangming Yuan^1,2, Xianjun Li^1,2, Yingfeng Zuo^1,2,*
1 College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
2 National Joint Engineering Research Center for Green Processing Technology of Agricultural and Forestry Biomass, Changsha, 410004, China
* Corresponding Author: Yingfeng Zuo. Email:
(This article belongs to this Special Issue: Renewable building materials and properties)

Journal of Renewable Materials 2020, 8(11), 1473-1488. https://doi.org/10.32604/jrm.2020.011788

Received 29 May 2020; Accepted 31 July 2020; Issue published 28 September 2020

Abstract

The Chinese fir wood was impregnated using a cyclic increasingpressure method (CIPM) with phenolic prepolymers as the impregnating modifier. Unmodified Chinese fir and progressive increasing-pressure method (PIPM) impregnated Chinese fir were used as reference samples and were compared and analyzed. The product’s chemical structure, internal morphology, crystal structure, and heat resistance were characterized. The transversal and longitudinal sections showed better filling effects, so that it bore greater external loading and reduced the water storage space. CIPM infused more phenolic prepolymer into the Chinese fir. Not only producing more physical filling but also forming more hydrogen bond associations and chemical bond combinations. Compared with PIPM and unmodi- fied Chinese fir, the CIPM impregnated Chinese fir had better mechanical strength and water resistance. The cellulose chains in CIPM impregnated Chinese fir were more closely linked and their crystallinity were clearly improved. Changes in internal morphology and crystal structure explained the reason why the mechanical properties and water resistance of CIPM impregnated Chinese fir were improved significantly. This Chinese fir had lower thermal decomposition rates, higher decomposition residual rates, and smaller combustion flames, which confirmed that it possessed improved heat and fire resistance.

---

Keywords

Chinese fir; phenolic prepolymer; cyclic increasing pressure method; chemical structure; crystalline structure; heat resistance

---

Citations