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Chiral Separation Abilities of Homogeneously Synthesized Cellulose 3,5-Dimethylphenylcarbamates: Influences of degree of substitution and Molecular Weight

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Chinese Journal of Polymer Science 2015年第12期33卷 1633-1633,1634-1639页

作者： Wei-wei Chen Mei-chun Ding Mei Zhang 张金明 Xia Gao Jia-song He 张军 Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Engineering Plastics Institute of ChemistryChinese Academy of Sciences (CAS) University of Chinese Academy of Sciences Beijing Center for Physical and Chemical Analysis Beijing Key Laboratory of Organic Materials Testing Technology & Quality Evaluation

A series of cellulose 3,5-dimethylphenylcarbamates （CDMPCs） with different degrees of substitution （DS） and degrees of polymerization （DP） were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride （AmimC1）. Then, the CDMPCs were coated on silica gel and used as chiral stationary phases （CSPs）, and their chiral recognition abilities for seven racemates were evaluated by high performance liquid chromatography. The results showed that DS and DP of CDMPCs had a great influence on chiral recognition abilities of the CSPs. The CSPs with the DS ~ 1 gives a low chiral recognition to most racemates. On the contrast, the CSPs with the DS _〉 2 exhibited high chiral separation abilities. For example, six racemates could be separated on the CSP with CDMPC of DS ~ 2 （CSP-2）. Especially, for the enantioseparation of 1-（2-naphthyl） ethanol and Tr6ger＇s base, CSP-2 gave the highest separation ability in all of CSPs. On the other hand, when the DP of cellulose was in a range from 39 to 220, the chiral separation abilities of CDMPCs increased as the DP increased. This work demonstrates that the structure of cellulose esters such as DS and DP has important effect on their chiral separation ability, and therefore provides a practical method to design and prepare desirable CSPs for different racemates.

关键词： Cellulose phenylcarbamate Ionic liquid degree of substitution degree of polymerization Chiral separation.

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Effects of degree of substitution on stearic acid-modified Bletilla striata polysaccharides nanoparticles and interactions between nanoparticles and bovine serum albumin

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Chinese Chemical Letters 2018年第12期29卷 1861-1864页

作者： Guangyuan Zhang Ji Wu Yuran Liu Long Huang Jin Qiao Xin Liu Jingyan Wei Qingxiang Guan School of Pharmacy Jilin University

Three kinds of stearic acid（SA）-modified Bletilla striata polysaccharides（BSPs-SA） conjugates with different degrees of substitution（DS） values of SA moiety were synthesized. The impacts of the DS values on the properties of BSPs-SA self-aggregated nanoparticles were determined. The interactions between bovine serum albumin（BSA） and the BSPs-SA nanoparticles were characterized using spectroscopic observations. The cytotoxicity was measured through 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide（MTT） method. The critical aggregation concentration and the average particle sizes reduced from 16.81 μg/mL to 3,09 μg/mL and 192.70 nm to 125.29 nm when the DS values of SA segment increased from 4.98% to 12.94%, respectively. The cumulative release percentage of docetaxel in BSPs-SA nanoparticles decreased whereas encapsulation efficiency and loading capacity increased along with the DS increase of SA moiety. The fluorescence and ultraviolet results demonstrated that the conformation of BSA did not show significant change after incubating with BSPs-SA ***, the mass ratio of BSA/BSPs-SA affected their affinity intensity. The inhibition capability of cell proliferation of docetaxel-loaded BSPs-SA nanoparticles against 4 T1 was superior to that of Duopafei;.BSPs-SA nanoparticles may become a promising nanocarrier for anticancer drugs by adjusting the DS values of the hydrophobic SA groups.

关键词： Bletilla striata Nanoparticles Bovine serum albumin Interaction degree of substitution

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Optical and Mechanical Properties of CMCNF-dispersed MMT/CMC-Na Nanocomposite Films: Influence of the degree of substitution of CMCNFs

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Paper And Biomaterials 2020年第4期5卷 18-26页

作者： Guanhui Li Gaoyuan Hou Hong Xie Dejian Zhang Jinyi Cui Zhiqiang Fang State Key Laboratory of Pulp and Paper Engineering GuangzhouGuangdong Province510640China Key Laboratory of Pulp and Paper Science&Technology of Ministry of Education/Shandong Province Qilu University of Technology(Shandong Academy of Sciences)Ji'nanShandong Province250353China

Carboxymethylated cellulose nanofibril(CMCNF)is an effective green dispersant to prepare well-dispersed monolayer montmorillonites(MMTs)in water,thereby facilitating the preparation of a high-performance MMT/polymer nanocomposite ***,not enough attention has been paid to correlating the degree of substitution(DS)of CMCNFs with the mechanical and optical properties of the final nanocomposite *** this study,a series of homogeneous monolayer MMT nanoplatelet dispersions was prepared initially using CMCNFs with different DS as a dispersant,and the as-prepared CMCNF-dispersed MMT dispersions were then mixed with sodium carboxymethyl cellulose(CMC-Na)to fabricate nacre-like nanocomposite films with different contents of MMTs through *** layered nanostructure and optical and mechanical properties of the asprepared CMCNF-dispersed MMT/CMC-Na nanocomposite films were investigated,which demonstrated that CMCNFs with lower DS have a positive effect on their optical and mechanical *** study sheds light on the preparation of MMT-based nanocomposite films with superior optical and mechanical properties.

关键词： carboxymethylated cellulose nanofibril degree of substitution green dispersant montmorillonite nanocomposite film

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Sustainable conversion regenerated cellulose into cellulose oleate by sonochemistry

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Frontiers of Chemical Science and Engineering 2023年第8期17卷 1096-1108页

作者： De-Fa Hou Pan-Pan Yuan Zi-Wei Feng Meng An Pei-Yao Li Can Liu Ming-Bo Yang National Joint Engineering Research Center for Highly-Efficient Utilization Technology of Forestry Resource Southwest Forestry UniversityKunming 650224China College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

Derivatization has great potential for the high-value utilization of cellulose by enhancing its processability and ***,due to the low reactivity of natural cellulose,it remains challenging to rapidly prepare cellulose derivatives with high degrees of ***“cavitation effect”of ultrasound can reduce the particle size and crystalline index of cellulose,which provides a possible method for preparing cellulose ***,a feasible method was proposed for efficiently converting regenerated cellulose to cellulose oleate with the assistance of ultrasonic *** adjusting the reaction conditions including ultrasonic intensity,feeding ratios of oleic acid,reaction time,and reaction solvent,a series of cellulose oleates with degrees of substitution ranging from 0.37 to 1.71 were ***,the effects of different reaction conditions on the chemical structures,crystalline structures,and thermal behaviors were investigated *** oleates with degrees of substitution exceeding 1.23 exhibited amorphous structures and thermoplasticity with glass transition temperatures at 159.8 to 172.6℃.This study presented a sustainable and practicable method for effectively derivatizing cellulose.

关键词： regenerated cellulose cellulose oleate sonochemistry degree of substitution thermoplasticity

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Preparation and Characterization of Acylated Chitosan

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Chemical Research in Chinese Universities 2005年第1期21卷 114-116页

作者： LIMing-ehun LIUChao XINMei-hua ZHAOHuang WANGMin FENGZhen SUNXiao-li CollegeofMaterialScienceandEngineering HuaqiaoUniversityQuanzhou362011P.R.China

Fully acylated chitosan and N, N-diacyl chitosan were prepared. The products were characterized by elemental analysis, FTIR and 1H NMR. The experimental results indicate that the average degree of acylation depends on the volume ratio of pyridine to chloroform in the reaction medium, the chain length of the acylation agent used, and the molecular weight of chitosan raw materials. The XRD measurements were carried out for pure chitosan, fully acylated chitosan and N, N-diacyl chitosan to verify the crystallinity change caused by the acylation.

关键词： Chitosan Acylation degree of substitution XRD

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STUDY ON THE CHARACTERIZATION OF DISTRIBUTION OF SUBSTITUENTS ALONG THE CHAINOF CARBOXYMETHYL CELLULOSE

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Chinese Journal of Polymer Science 1989年第1期7卷 45-53页

作者：马志艺张维邦李卓美 Institute of Polymer Science Zhongshan University

Four new paranmeters, and , and have been proposed to describe the average length of the sequence of substituted anhydroglucose units and that of unsubstituted ones respectively along the CMC chain. The methods for determining those parameters have also been presented . Six CMC samples have been characterized in terms of intrinsic viscosity, degree of substitution （DS）, index of substitution（SI）;and . It has been proved experimentally that, not only can describe the sequence distribution along the CMC chain, but also can be used for calculating SI and estimating the average degree of substitution in the substituted glucose rings.

关键词： Carboxymethylcellulose degree of substitution Sequence distribution

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Investigation on Mechanical Properties of CMSLDS/Acrylate Copolymeric Blending Films for Warp Sizing

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Journal of Donghua University(English Edition) 2010年第1期27卷 36-40页

作者：乔志勇祝志峰张斌 Key Laboratory of Eco-textile Ministry of EducationJiangnan University College of Textiles Donghua University

Carboxymethyl starch with lower degree of substitution was, blended with acrylate copolymer for revealing the relation between mechanical properties and chemical structure of blending film. Effects of carboxymethylation of starch, acrylate constituent units of acrylate copolymers, and copolymer content of the film on the properties were investigated. The mechanical properties were evaluated in terms of tensile strength, breaking elongation, abrasion resistance, and flex-fatigue resistance. Film morphology was examined with X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and atomic force microscope （AFM）. It was found that the properties depended on the degree of substitution of carboxymethyl starch, chemical structure of acrylate units, and content of acrylate copolymer. Phase-separation of the two ingredients occurred within film matrix and the separation was decreased after starch carboxymethylation. Breaking elongation and flex-fatigue resistance of the film reached maximmns when acrylate copolymer content was 50%. Excessively increasing the content of acrylate copolymer reduced the film properties.

关键词： carboxymethyl starch acrylate copolymer blending film mechanical properties degree of substitution

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Antoioxidant Activity of Carboxymethyl Chitosan with Different Substituted degrees

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Agricultural Science & Technology 2008年第1期9卷 5-7,59页

作者：姚倩孙涛周冬香毛芳上海水产大学食品学院

[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan （NOA, NOB and NOC）with various degrees of substitution （DS）were obtained by etherizing chito-oligosacchaside. Their structure and substituted degree were characterized and their antioxldant activity to·OH was evaluated. [ Result] The IC50 s of NOA ,NOB and NOC were 0.15 ,0. 29 ,0. 23 mg/ml while their DSs of -NH2 position（DSN） were 0.51,0.29 and 0.38 and DSo were 0. 74 ,0. 84 ,0. 97respectively.[ Conclusion] With the increase of DSN ,antioxidant activity of N,O-carboxymethyl chitosan oligosaccharide to·OH was up.

关键词： Chitosan oligosaccharide Carboxymethyl chitosan oligosaccharide degree of substitution Antioxidant activity

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