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首页> 外文学位 >Grafting furfuryl alcohol and polyfurfuryl alcohol to cellulose and lignocellulose fibers.
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Grafting furfuryl alcohol and polyfurfuryl alcohol to cellulose and lignocellulose fibers.

机译：将糠醇和聚糠醇接枝到纤维素和木质纤维素纤维上。

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摘要

Due to the limited supply and the toxicity of chemicals used to prepare synthetic resins utilized in the Forest Products Industries new techniques for wood bonding have been recently developed. One of these is the nonconventional method of wood bonding developed at the University of California, Forest Products Laboratory. This method utilizes the non-petroleum derived chemicals such as furfuryl alcohol, lignosulfonate and maleic anhydride in presence of oxidants such as H202-Fe2+ or nitric acid to bond wood surfaces. In this study the elucidation of the mechanism of such bonding was attempted by studying the grafting of furfuryl alcohol and its polymer to cellulose fiber.;It was found that polyfurfuryl alcohol (PFA) successfully grafted to cellulose fiber in the aqueous solution at pH 2.0 and 90 oC using H202-Fe2+ as an oxidizing agent. Reaction parameters such as molecular weight of PFA's, H202 concentration, and the addition of hydroquinone had a pronounced effect on the grafting; at the same time the variation in the types of acids used to adjust the pH of aqueous grafting phase, and in the nature of gases led through the reaction medium did not change the results of grafting. Adding oxidant at once or over a period of 15, 30 and 45 minutes did not affect the results either.;The products from the reaction of polyfurfuryl alcohol with H202-Fe2+ were characterized. Wet methods of the polymer and organic analytical chemistry as well as physicochemical methods were employed to study the structure of these polymers. It was concluded that the activation of PFA by H202-Fe2+ is the major reaction responsible for the grafting. The more detailed mechanisms of grafting PFA were then proposed based on the data obtained from the graft-copolymerization of PFA model compounds and cellulose fiber. It was found that grafting was initiated largely through the activation of methylene group adjoining the furan end unit of the PFA polymer chain.;The properties of the PFA grafted fibers in the form of handsheet paper together with the effects of the post-treatment (i.e. hot pressing, spraying with aqueous acid and hot pressing, or spraying with an oxidant and then hot pressing) on the properties of the grafted papers were studied. It was observed that post-treatments significantly improved the wet strength of grafted papers, especially when the paper was sprayed with H202-Fe2+ oxidant and then hot pressed.
机译：由于有限的供应和用于制备林产品工业中使用的合成树脂的化学药品的毒性，最近已经开发了用于木材粘合的新技术。其中之一是由加利福尼亚大学林产品实验室开发的非常规木材粘合方法。该方法利用非石油衍生的化学品（例如糠醇，木质素磺酸盐和马来酸酐）在氧化剂（例如H2O2-Fe2 +或硝酸）的存在下粘合木材表面。在这项研究中，通过研究糠醇及其聚合物接枝到纤维素纤维上，试图阐明这种键合的机理。；发现在pH 2.0的水溶液中，聚糠醇（PFA）成功地接枝到了纤维素纤维上。使用H2O2-Fe2 +作为氧化剂，在90 oC。反应参数如PFA的分子量，H2O2的浓度和对苯二酚的添加对接枝有显着影响。同时，用于调节水性接枝相pH的酸类型的变化以及通过反应介质引入的气体的性质不会改变接枝的结果。一次或在15、30和45分钟内添加氧化剂也不影响结果。;表征了糠醇与H 2 O 2 -Fe 2+反应的产物。聚合物和有机分析化学的湿法以及物理化学方法被用来研究这些聚合物的结构。结论是，H 2 O 2 -Fe 2+活化PFA是引起接枝的主要反应。然后根据从PFA模型化合物和纤维素纤维的接枝共聚获得的数据，提出了更详细的PFA接枝机理。发现接枝主要是通过活化PFA聚合物链呋喃末端单元附近的亚甲基来引发的。PFA接枝纤维以手抄纸的形式表现出的特性以及后处理的效果（即对接枝纸的性能进行了研究（热压，酸水溶液喷涂和热压，或先用氧化剂喷涂然后热压）。观察到，后处理显着提高了接枝纸的湿强度，特别是在纸上喷有H2O2-Fe2 +氧化剂然后进行热压时。

著录项

  • 作者

    Nguyen, Charles Chieu H.;

  • 作者单位

    University of California, Berkeley.;

  • 授予单位 University of California, Berkeley.;
  • 学科 Chemistry Polymer.;Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 1989
  • 页码 242 p.
  • 总页数 242
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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