酶预处理对马尾松纤维结构和性能与微纤丝初步制备的影响

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1、纤维素酶用量大于0.5CMCU/g时，结晶度稳定在80%-82%。内切纤维素酶主要作用于无定形区。复合、外切纤维素酶用量较小时，主要作用于无定形区，结晶度增大；酶用量较大时，结晶区和无定形区同时被水解，无定形区水解程度大时，结晶度升高，反之，结晶度降低。复合、外切纤维素酶用量增加时，纤维的保水值、打浆度和表面电荷都先降低后逐渐增加。复合纤维素酶用量为20.0FPU/g时，保水值、打浆度和Zeta电位绝对值分别由153.23%、11°SR、64.9mV增加至196.57%、56°SR、68.5mV。外切纤维素酶用量为10.0FPU/g时，三者分别增加至20

2、0.13%、34°SR、66.4mV。而内切纤维素酶用量增加时，纤维的保水值和Zeta电位绝对值逐渐降低，打浆度略微降低后逐渐增加。内切纤维素酶用量为50.0CMCU/g时，保水值和Zeta电位分别下降至103.92%、23.6mV，打浆度增加至35°SR。实验对CMF的制备进行了初步研究，纤维经预处理后以1.5%的浓度，通过均质机循环30次，制备出的CMF直径分布在20nm-60nm。CMF悬浮液呈半透明的凝胶状，具有较好的透光性和稳定性，阳离子需求量是对照样纤维的10倍。经FTIR、XRD和TGA发现CMF与天然纤维素的分子结构、晶型结构和热稳定性基

3、本相同。CMF的结晶度介于未经过任何处理的对照样纤维和经酶预处理后的纤维之间。关键词：纤维素酶，纤维素微纤丝，酶预处理，纤维形态，结晶度IIINFLUENCEOFENZYMATICPRETREATMENTONSTRUCTURESANDPERFORMANCESOFMASSONPINEFIBERSANDTHEPRELIMINARYPREPARATIONOFCELLULOSEMICROFIBRILABSTRACTAsanovelnano-cellulosematerial,cellulosemicrofibril(CMF)withabrightmarketpr

4、ospectoffersexcellentmechanicalperformance,barrierpropertyandtransmittance.ButthehighmechanicalconsumptioningrindingpreparationisthemainreasontohinderthesuccessfulcommercializationofCMF,whiletheenzymaticpretreatmenthasagreatpotentialintheaspectofreducingthedissociationenergyconsu

5、mption.DomesticandforeignresearchesonthepreparationofCMFbyenzymaticpretreatmentaremorefocusedontheapplicationandcharacterizationofphysicalproperties,buttherearefewresearchesonthemechanismofenzymaticpretreatmentandtheeffectofenzymaticpretreatmentonfibermorphologyandaggregationstru

6、cture.Duetothecomplexityofcelluloseandhydrolysissubstrate,theanalysesonthechangesoffibermorphologyandaggregationstructureafterenzymatichydrolysisarenotconsistent.Therefore,thispaperfocusesonenzymaticpretreatmentasthekeypointofpreparationofCMFbyenzymaticpretreatment.Themassonpinef

7、iberswerepretreatedbycomplexcellulase,endo-cellulaseandexo-cellulase,utilizingthehighpressurehomogeneoustoprepareCMF.Thegeneralrulesoftheeffectsofenzymatichydrolysisonthefibermorphologiesandstructuresandperformanceswerestudiedtorevealthemechanismofenzymaticpretreatment.Itwillprov

8、ideatheoreticalbasisfortheselectionofcel