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白腐菌降解木质纤维素顺序规律的研究 总被引:19,自引:0,他引:19
通过纤维素、半纤维素和木质素三者含量变化的测定,以及傅立叶变换红外光谱(FTIR)的谱图分析,研究了 BP2、CD1和 AX3三株白腐菌在50 天培养期中降解木屑基质中木质纤维素的规律。结果表明,三株白腐菌对木屑基质中纤维素、半纤维素和木质素三者的降解具有一定的顺序和选择性,即先降解半纤维素和木质素,再同时降解半纤维素、纤维素和木质素;从降解比例来看,三株菌对木质素具有很强的降解优势(45%左右)和选择性(0.5左右)。木质素的相关谱带(1630,1510,1325 和 1265 cm-1)强度及半纤维素和纤维素的相关谱带强度(1740,1325,1160 和 898 cm-1)的变化也证实了这一结论。 相似文献
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微晶纤维素的开发及应用 总被引:1,自引:0,他引:1
前言 纤维素广泛存在于自然界,是人类的宝贵财富。据专家估计,全球每年可生产数千亿吨纤维素,是石油无法比拟的可更新的重大资源。 微品纤维素(MCC)是天然纤维素经稀酸水解至极限聚合度(LOOP)的固体产物。1875年Girard首次将纤维素稀酸水解的固体产物命名为“水解纤维素”以来,在相当长的一段时间里被视为无法利用的产品。直至六十年代微品纤维素形成商品以 相似文献
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微晶纤维素悬浮液在机械力的作用下发生微纤化而形成胶体。本文用流变仪研究了微晶纤维素胶体溶液的速度梯度与应力、浓度与粘度、温度与粘度之间的关系;同时研究了酸碱性、盐类对粘度的影响,以及胶体的储存稳定性。此外,用电导仪测量了胶体的电性质,展示了微晶纤维素胶体的独特性质。 相似文献
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以硅酸钠、硫酸铝、硫酸镁、纤维素为原料,制备了聚硅酸铝镁-纤维素(PSiAM-CMC)无机-有机复合絮凝剂并应用于模拟江水的净水处理。实验表明,当制备条件为n(Al Mg)/n(Si)=0.6、n(Mg)/n(Al)=1:4、纤维素与硅的质量比为0.3、纤维素糊化温度为60℃、pH=2时,PSiAM-CMC对模拟江水的絮凝效果最好,除浊率可达99%。采用扫描电镜、傅立叶红外光谱、X射线衍射分析对絮凝剂进行表征,结果表明,聚硅酸、金属盐和纤维素并不是简单的混合,而是发生了缩聚和配位反应,形成一种新的化合物,该化合物兼具无机和有机絮凝剂的优点,是一种环保高效的新型絮凝剂。 相似文献
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作为天然植物纤维原料制品,微晶纤维素在医药食品工业中具有先天的优势和独特的性质,是多功能的辅料[1]。国外微晶纤维素产品主要是以特殊等级的高α-纤维素含量的纯木材纤维素为原料,而国内传统采用棉为原料,其中棉短绒中纤维素含量较高,约在90%以上,是制备微晶纤维素的良好原料[2]。本实验主要探讨由棉短绒制备微晶纤维素的条件。实验发现脱脂过程中氢氧化钠浓度和脱脂时间有较大影响,最佳条件为20%氢氧化钠溶液室温下浸泡72 h,然后在90~95℃水浴温度下搅拌约220 min。脱脂后的棉短绒经过氧化氢漂白后直接用盐酸催化水解,水解过程中盐酸浓度、时间和温度对最终产物影响较大,结晶最好的条件为10%盐酸、90℃搅拌水解145 min。测试了产物的XRD,证明所得的产物有较好的结晶度。 相似文献
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研究了微晶纤维素(MCC)和改性微晶纤维素(MMCC)的用量对丁苯橡胶(SBR)硫化胶物理机械性能的影响,以及分别填充20phrMCC和MMCC的SBR复合材料的耐磨性和动态力学性能分析。结果表明,当MCC和MMCC的用量都为20phr时,硫化胶有最大的拉伸强度,分别为15.3MPa和19.0MPa;填充MMCC的SBR复合材料的磨耗体积比填充MCC的降低了41%;填充20phr的MCC和MMCC的SBR具有相似的玻璃化温度。 相似文献
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Anupam Glorious Lobo Abdul Mujeeb Mahammad Nawaz Adeeb Aman A. P. Abdul Basith 《Polymer-Plastics Technology and Engineering》2016,55(16):1713-1719
Elucidation of the structure of naturally existing or synthesized substances is an important criterion in the study of materials to predict the application of the substance. In this study, polylactide was doped with nano-aluminium oxide and nano-cupric oxide with 1 and 3 mg of concentration variants. The interaction between the polymer matrix and the nanoparticles has been studied using Fourier transform infrared. Successful doping of the polymer has been observed. Attention has been drawn to check the intermolecular bonding in films having varying thicknesses, films prepared at higher sonication temperatures, and chemical homogeneity of the doped polymer films. 相似文献
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微晶纤维素胶体的流变性研究 总被引:1,自引:0,他引:1
本文研究了微晶纤维素肢体的流变性质.微晶纤维素肢体为触变性流体,它的贮存稳定性、热稳定性和酸碱稳定性优于羧甲基纤维素.按Ostwade幂方程式算出它的触变系数及按Green-Weltmann方程式算出它的时间融变系数和拆散触变系数都比较大。 相似文献
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微晶纤维素的微细结构研究 总被引:8,自引:0,他引:8
研究了各种纤维素材料及不同酸浓度水解制成的微晶纤维素的聚合度,并用X-射线衍射法研究结晶度、结晶形态、晶粒尺寸和颗粒大小;用透射电镜(TEM)观察颗粒形状和大小,发现不同纤维素材料达到平衡聚合度(LODP)的盐酸浓度略有不同;在酸水解过程中纤维素的结晶形态、晶粒尺寸和颗粒大小基本不变,而且用X-射线衍射及TEM测出的颗粒不是纤维素晶粒,而是微原纤。 相似文献
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硅灰石分子结构的FTIR谱 总被引:2,自引:1,他引:2
提供了一种研究链状硅酸盐矿物红外吸收谱归属的实验方法.1Tr型普通硅灰石酸解产物的Fourier变换红外(Fourier transform infrared,FTIR)谱研究表明:根据FTIR谱随酸解时间延长的演变规律,硅灰石的FTIR谱中所有吸收谱带的归属均可确切指定.1Tr型普通硅灰石的FTIR谱归属为:1 085cm-1吸收带是OT-Si-OT(桥氧)非对称伸缩振动产生的,1 060cm-1和1 018 cm-1吸收带是Si-OT-Si非对称伸缩振动形成的,967cm-1吸收带是OB-Si-OB(非桥氧)对称伸缩振动引起的,927cm-1和902cm-1吸收带是OT-Si-OB非对称伸缩振动产生的,681 cm-1和645 cm-1吸收带是Si-OB-Si对称伸缩振动吸收形成的,567cm-1和509cm-1吸收带是Si-OB弯曲振动吸收产生的,472 cm-1吸收带是Si-OT弯曲振动吸收的结果,453 cm-1吸收带是M-OT(M代表Ca)伸缩振动吸收产生的.另外,酸解产物的FTIR谱中799和1 160~1 250 cm-1附近的吸收带提供了硅灰石酸解二氧化硅的有序度随酸解时间延长而逐渐增大的证据. 相似文献
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By thermally treating a commercial cellulose in ethylene glycol, celluloses of controlled low degree of polymerization, DPr = 1000 to 70, can be derived. Two general behaviors are observed in the range studied. At first, the depolymerization reaction is predominant down to a DP equal to 130. Beyond this level, the depolymerization process leads to extensive solubilization of the cellulose. The treated celluloses have been analyzed by X-ray diffraction, FTIR, TGA, elemental analysis and enzymatic hydrolysis. No chemical change of the cellulose could explain the two different behaviors. A physical modification in the form of depolymerization and destructuration is suspected. 相似文献
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Crude cellulose was isolated from rice straw and then converted into microcrystalline cellulose (MCC) via partial hydrolysis. Both the isolation and partial hydrolysis were carried out under microwave. Rice straw was successively pretreated with alkaline and acid solutions before hydrolysis. Lignin and silica were almost removed but partial removal of hemicellulose in dilute alkali solution, and the residual hemicellulose was further removed in dilute acid solution. The total removal rates of hemicellulose, lignin and silica reached up 92.0%, 98.5%, and 96.8%, respectively. The cellulose content of 93.6 wt % in MCC was given by partial hydrolysis of crude cellulose isolated from rice straw. The comparison between microwave irradiation and traditional heating method was also investigated. Compared to traditional heating method, similar results were obtained while milder conditions, including shorter time and lower temperature, were required. An effective microwave‐assisted and energy‐efficient methodology using rice straw as the alternative source of cellulose fiber was developed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44901. 相似文献