【摘要】：隨著環(huán)境污染和能源危機(jī)的日益突顯,以可再生木質(zhì)纖維原料制備能源、材料及化學(xué)品已成為研究的熱點(diǎn)和重點(diǎn)。在積極倡導(dǎo)綠色環(huán)保理念,追求人與環(huán)境和諧發(fā)展的今天,結(jié)合生物質(zhì)預(yù)處理技術(shù)研制開發(fā)環(huán)境友好型生物質(zhì)復(fù)合材料是實(shí)現(xiàn)這一目標(biāo)的有效途徑。本文通過水熱與漆酶介體預(yù)處理相結(jié)合的方法對(duì)纖維進(jìn)行了界面改性,研究了水熱和漆酶介體預(yù)處理之后纖維和木質(zhì)素的結(jié)構(gòu)變化；以竹材為原料,應(yīng)用從生物乙醇發(fā)酵后的堿木質(zhì)素殘?jiān)鳛樘烊荒z黏物質(zhì),采用熱壓的方法制備刨花板,并從中分離出木質(zhì)素組分進(jìn)行結(jié)構(gòu)分析；為進(jìn)一步研究木質(zhì)素在熱壓過程中結(jié)構(gòu)的變化,采用逐漸升高溫度單獨(dú)熱壓木質(zhì)素的方法,研究了木質(zhì)素在熱壓過程中的結(jié)構(gòu)轉(zhuǎn)變和膠合機(jī)理。本文主要研究?jī)?nèi)容和結(jié)果如下：(1)纖維經(jīng)過水熱預(yù)處理后,纖維中的一部分半纖維素和木質(zhì)素降解溶出,在纖維的表面出現(xiàn)了孔洞和顆粒物,纖維的可及度和結(jié)晶度增加。纖維經(jīng)過漆酶介體預(yù)處理后,使木質(zhì)素發(fā)生了降解,分子量降低。水熱和漆酶介體綜合預(yù)處理后,木質(zhì)素的β-O-4'連接鍵發(fā)生了斷裂,G'型單元含量減少,S/G比率和酚羥基含量大大增加。(2)把堿木質(zhì)素和竹材碎料混合,在溫度180℃,壓力5 MPa,時(shí)間20 min,木質(zhì)素／竹材碎料=0.4的熱壓制備工藝條件下,獲得了內(nèi)結(jié)合強(qiáng)度達(dá)到1.36 MPa的物理機(jī)械強(qiáng)度。通過分析分離制備的木質(zhì)素,發(fā)現(xiàn)熱壓過程中造成木質(zhì)素的β-O-4'芳醚鍵斷裂,G和H型木質(zhì)素單元比例以及酚羥基的含量增加。木質(zhì)素骨架中芳醚鍵和功能基團(tuán)的轉(zhuǎn)變的增加了木質(zhì)素單元苯環(huán)的反應(yīng)活性,有利于C-C鍵的形成,有效的促進(jìn)了耦合交聯(lián)反應(yīng)的發(fā)生。(3)木質(zhì)素在單獨(dú)熱壓之后,木質(zhì)素大分子骨架中β-O-4'芳醚鍵含量降低和分子量增加,縮合的C-C鍵和酚羥基含量增加。另外,隨熱壓溫度的上升,木質(zhì)素的玻璃化轉(zhuǎn)變溫度也相應(yīng)升高�？偟膩碚f,在熱壓過程中,木質(zhì)素的斷裂和交聯(lián)反應(yīng)是一對(duì)協(xié)同反應(yīng),同時(shí)發(fā)生。全面深刻的了解木質(zhì)素在熱壓過程中的反應(yīng)活性和化學(xué)結(jié)構(gòu)轉(zhuǎn)變可以為其在木質(zhì)復(fù)合材料中的廣泛應(yīng)用提供非常有價(jià)值的方法與理論指導(dǎo)。
[Abstract]:With the increasing prominence of environmental pollution and energy crisis, the preparation of energy, materials and chemicals from renewable wood fiber has become the focus of research. Today, when we actively advocate the concept of green environmental protection and pursue the harmonious development of human and environment, the research and development of environmentally friendly biomass composites combined with biomass pretreatment technology is an effective way to achieve this goal. In this paper, the interfacial modification of the fiber was carried out by means of hydrothermal and laccase pretreatment, and the structural changes of fiber and lignin after hydrothermal and laccase pretreatment were studied. Using bamboo as raw material, alkali lignin residue fermented from biological ethanol as natural adhesive, particle board was prepared by hot pressing, and lignin components were separated from it for structural analysis. In order to further study the structural change of lignin during hot pressing, the structural transformation and bonding mechanism of lignin during hot pressing were studied by increasing the temperature and pressing lignin alone. The main contents and results of this paper are as follows: (1) after hydrothermal pretreatment, some hemicellulose and lignin in the fiber are degraded and dissolved, pores and particles appear on the surface of the fiber, and the accessibility and crystallization of the fiber increase. After pretreatment with laccase mediator, lignin was degraded and molecular weight decreased. After comprehensive pretreatment of hydrothermal and laccase mediators, the 尾-O 鈮，

本文編號(hào)：2476690