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Chinese Journal of Chemical Engineering 2024年第11期75卷 214-221页

作者： Jiawei Wu Zhihong Chen Zhongwen Si Xiaoling Lou Junxian Yun State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology College of Chemical EngineeringZhejiang University of TechnologyHangzhou 310032China

polylactic acid(PLA)is a potential polymer material used as a substitute for traditional plastics,and the accurate molecular weight distribution range of PLA is strictly required in practical ***,exploring the relationship between synthetic conditions and PLA molecular weight is crucially *** this work,direct polycondensation combined with overlay sampling uniform design(OSUD)was applied to synthesize the low molecular weight *** a multiple regression model and two artificial neural network models on PLA molecular weight versus reaction temperature,reaction time,and catalyst dosage were developed for PLA molecular weight *** characterization results indicated that the low molecular weight PLA was efficiently synthesized under this ***,the experimental dataset acquired from OSUD successfully established three predictive models for PLA molecular *** them,both artificial neural network models had significantly better predictive performance than the regression ***,the radial basis function neural network model had the best predictive accuracy with only 11.9%of mean relative error on the validation dataset,which improved by 67.7%compared with the traditional multiple regression *** work successfully predicted PLA molecular weight in a direct polycondensation process using artificial neural network models combined with OSUD,which provided guidance for the future implementation of molecular weight-controlled polymer's synthesis.

关键词： polylactic acid Molecular weight prediction Overlay sampling uniform design Neural network model

Mechanical Property Evaluation of Glass-carbon-durian Skin Fiber Reinforced polylactic acid Composites

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Journal of Wuhan University of Technology(Materials Science) 2023年第1期38卷 244-247页

作者： Boonsin Nadondu Prayoon Surin Jakawat Deeying Faculty of Engineering Pathumwan Institute of TechnologyBangkok 10330Thailand Science and Technology Research Institute King Mongkut’s University of Technology North BangkokBangkok 10800Thailand

The main objective of this work was to study and develop composite materials by experiments with mixtures of synthetic(glass fiber, carbon fiber) and natural fiber(durian skin fiber) reinforcements on a polylactic acid(PLA) matrix composite, because of its excellent mechanical properties. Durian skin fiber(DSF) is a natural waste throughout Thailand, and an alternative to recycling is to realize its potential as a new reinforcement through mixing and the injection molding processes. The flexural strength(σ_(F)) and flexural modulus(E_(F)) of the composites from specimens showed a maximum value by content of durian skin fiber at 10 wt%, for good performance relative to particle dispersion between the matrix and the fiber, and showed a minimum value by content of durian skin fiber at 20 wt%, because the reinforcement material affects the mechanical properties in the experiments.

关键词： glass fiber carbon fiber durian skin fiber polylactic acid mechanical properties

Preparation and Performance of Pueraria lobata Root Powder/polylactic acid Composite Films

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Journal of Renewable Materials 2023年第6期11卷 2531-2553页

作者： Shuang Zhao Shenglan Chen Shuan Ren Gang Li Ke Song Jie Guo Shima Liu Jian He Xianwu Zhou Key Laboratory of Hunan Forest Products and Chemical Industry Engineering Jishou UniversityZhangjiajie427000China Central South Inventory and Planning Institute of National Forestry and Grassland Administration Changsha410000China School of Civil Engineering and Architecture Jishou UniversityZhangjiajie427000China College of Chemistry and Chemical Engineering Jishou UniversityJishou416000China

Petroleum-based materials,such as plastic,are characterized by adverse environmental pollution;as a result,researchers have sought alternative degradable plastics that are environmentally friendly,such as polylactic acid(PLA).PLA has shown great potential to replace petroleum-based *** this study,seven different samples of unmodified Pueraria lobata root powder(PRP)with different contents(i.e.,0,5,10,15,20,25,and 30 wt%)and three different modified PRPs(i.e.,treated with NaOH,NaOH-KH-550,and Formic)were used to reinforce polylactic acid(PLA)via solution casting *** prepared PRP/PLA composite films were characterized using SEM,FTIR,UV-visible spectra analysis,TG,DSC,weight loss measurement(wt%),and mechanical *** results showed that the PRP modified with KH-550(PRPK)intensified the interaction in the interface region between the PRP and the PLA matrix,thus increasing the tensile strength(54.5 MPa),elongation at break(2.8%),and Young’s modulus(3310 MPa)of the PRPK/PLA *** angle measurement showed that the PRP treatments contributed to the hydrophobicity of *** transparency of PRP-10/PLA film atλ_(800)was 11.09%,and its UVA and UVB transmittance were 3.28 and 1.16,*** blending PLA with PRP,the PRP/PLA composite films exhibited excellent *** summary,PRPK improved the mechanical properties of PLA and prevented the films from ultraviolet light,suggesting that PRPK-5/PLA film could be used as packaging materials.

关键词： Pueraria lobata root powder polylactic acid biocomposite films properties

Effect of Starch/polylactic acid Ratio on the Interdependence of Two-Phase and the Properties of Composites

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Journal of Wuhan University of Technology(Materials Science) 2015年第5期30卷 1108-1114页

作者：左迎峰 GU Jiyou CAO Jun WEI Shuangying TAN Haiyan 张彦华 Key Laboratory of Bio-Based Material Science and Technology Northeast Forestry University Ministry of Education College of Material Science & Engineering Central South University of Forestry & Technology

Starch/polylactic acid(PLA) composites were prepared by melt extrusion, with corn starch and PLA as raw materials, glycerol as the plasticizer. Effects of starch/PLA ratio on the interdependence of two-phase and other properties of the composites were studied. The combination of results of TGA with SEM indicated that the interdependence between starch and PLA was increased gradually as the starch/PLA ratio reduced. DSC results showed that the glass transition temperature(Tg), melting temperature(Tm) and degree of crystallinity of PLA in composites were increased gradually, whereas the cold crystallization temperature(Tc) was gradually decreased as the starch/PLA ratio reduced. The rheological properties of composites were closely related with the interdependence of two-phase, with reducing starch/PLA proportion, the interdependence was increased, and then the strain for storage modulus was firstl reduced and then gradually increased. Frequency scanning showed that the storage modulus and complex viscosity were decreased with reducing starch content. As the starch/PLA ratio reduced, the matrix phase PLA was increased, so that the strength of composites was increased gradually, whereas water absorption rate was decreased gradually.

关键词： corn starch polylactic acid mixing ratio interdependence of two-phase properties

Lactoferrin-Conjugated polylactic acid Nanobubbles Encapsulated Perfluoropentane as a Contrast Agent for Ultrasound/Magnetic Resonance Dual-Modality Imaging

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Journal of Renewable Materials 2022年第3期10卷 767-780页

作者： Liqiong Ding Pingsheng Li Liu He Fengnan Xu Jieqiong Ding Binhua Luo School of Pharmacy Hubei University of Science and TechnologyXianning437100China Pharmacy Department of the Second Affiliated Hospital Hubei University of Science and TechnologyXianning437100China School of Basic Medical Sciences Hubei University of Science and TechnologyXianning437100China

The development of contrast agents that can be activated by multiple modes is of great significance for tumor *** this study,the lactoferrin(Lf)-conjugated polylactic acid(PLLA)nanobubbles(Lf-PLLA NBs)were used to encapsulate liquid perfluoropentane(PFP)with the double emulsion method,creating PFP loaded(PFP/Lf-PLLA)NBs for the ultrasound/magnetic resonance dual-modality imaging of subcutaneous *** parti-cle diameter and stability of nanobubbles were investigated by photon correlation *** biocompat-ibility of nanobubbles was preliminarily evaluated by cell proliferation and migration assay,hemolysis rate,and blood biochemistry analysis.A B-mode clinical ultrasound real-time imaging system was used to perform ultra-sonic imaging in *** resonance imaging in vivo was applied with a clinical 3.0 T magnetic resonance imaging(MRI)scanner *** mean particle diameter of PFP/Lf-PLLA NBs was 320.2±4.1 nm with a low polydispersity index(PDI,0.145±0.025),and the NBs were negatively charged(−11.4±0.4 mV).The transmis-sion electron microscopy(TEM)results showed that PFP/Lf-PLLA NBs exhibited highly monodispersed and pos-sessed an obvious spherical structure of *** had good stability at 4°*** concentrations of the PFP/Lf-PLLA NBs solution had no effect on the cell in cytotoxicity and cell migration,and the results of hemolysis rate and blood biochemistry assay also indicated the good biocompatibility of *** the ultrasound/magnetic resonance imaging of tumor-bearing mice,PFP/Lf-PLLA NBs showed signifi-cantly enhanced contrast ability of tumor ***,PFP/Lf-PLLA NBs had great potential to be a contrast agent for tumor dual-modality imaging in vivo.

关键词： Lactoferrin polylactic acid nanobubbles contrast agent ultrasound/magnetic resonance imaging

Lanthanum doped octacalcium phosphate/polylactic acid scaffold fabricated by 3D printing for bone tissue engineering

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Journal of Materials Science & Technology 2022年第23期118卷 229-242页

作者： Zeya Xu Bin Lin Chaoqian Zhao Yanjin Lu Tingting Huang Yan Chen Jungang Li Rongcan Wu Wenge Liu Jinxin Lin Key Laboratory of Optoelectronic Materials Chemical and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences155 West Yangqiao RoadFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China Orthopedics Department Fujian Medical University Union HospitalFuzhou 350001China

Lanthanum(La)has tremendous potential in the treatment and prevention of bone diseases especially osteoporosis and metabolic ***,controlling its distribution and keeping the release of La^(3+)ions sustained and steady in the body is still a big *** this study,we prepared La-OCP powders via co-precipitation method,and further prepared La-OCP/PLA porous scaffolds by 3 D ***^(3+)was successfully introduced into the OCP crystal structure and substituted Ca^(2+)at the Ca-5 and Ca-8 *** particular,some La^(3+)ions were deposited on the crystal surface in the form of *** octacalcium phosphate(OCP,Ca_(8)H_(2)(PO_(4))_6·5 H_(2)O)crystals and nanoparticles played as the carriers for La^(3+)*** La-OCP/PLA scaffolds displayed obvious mineralization effects and sustained release of La^(3+).The scaffolds contained a uniform structure with rough micro surface topography which acted as a suitable pathway for BMSCs cells to adhere,grow and *** a certain La^(3+)concentration,the extracts from La-OCP/PLA scaffolds increased the expression of osteogenesis-related genes,thus promoting the osteogenic differentiation of ***,the extracts regulated the immune *** experiment in vivo proved that La-OCP/PLA porous scaffolds were safe and could enhance bone defect regeneration in *** findings suggest that 3 D printed La-OCP/PLA porous scaffolds have promising potentials in bone tissue engineering.

关键词： Lanthanum Octacalcium phosphate Scaffold 3D printing Bone tissue engineering polylactic acid

Improvement in the Performance of the polylactic acid Composites by Using Deep Eutectic Solvent Treated Pulp Fiber

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Journal of Renewable Materials 2021年第11期9卷 1897-1911页

作者： Lei Tan Liangxian Liu Chaodong Liu Weihong Wang Key Laboratory of Bio-Based Material Science and Technology(Ministry of Education) Material Science and Engineering CollegeNortheast Forestry UniversityHarbin150040China

As the most favorable alternative to petroleum-based polymers,polylactic acid(PLA)which is the most promising degradable polymer has attracted increasing ***,the addition of cellulose to improve its strength often results in a reduction in its *** this work,microscale cellulose is first prepared from pulp fibers by using a deep eutectic solvent,and then is used as the reinforcement of PLA.A microcrystalline cellulose(MCC)/PLA sheet with uniform texture is obtained by the solution mixing,melt blending,hot-pressing and cold-pressing *** effects of MCC on the crystallization,thermal stability and mechanical properties of the PLA matrix were *** the addition of 1%cellulose fiber,the tensile strength of MCC/PLA composite sheet increased by 27%,and the elongation at break did not shown an evident *** strength enhancement mechanism was elucidated using scanning electron microscopy,differential scanning calorimetry,and dynamic thermomechanical *** energy dissipation during the deformation process and the compatibility of AMCC and rougher surface of MCC play important role in the strength ***,UV spectroscopy showed that the composite material absorbed some ultraviolet *** results show that the combined use of a deep eutectic solvent and solution mixing is an effective approach for improving the strength of PLA while maintaining its toughness.

关键词： polylactic acid microcrystalline cellulose deep eutectic solvent mechanical properties

Biodegradation and Mechanical Property of polylactic acid/Thermoplastic Starch Blends with Poly (ethylene glycol)

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Journal of Wuhan University of Technology(Materials Science) 2013年第1期28卷 157-162页

作者：薛平 WANG Kejian 贾明印 YANG Meijuan Institute of Plastics Machinery and Engineering Beijing University of Chemical Technology

The effects of adding poly （ethylene glycol）（PEG） into polylactic acid/thermoplastic starch blends （PLA/TPS） on the properties were investigated by DSC, SEM and mechanical property-testing. The blends of PLA/TPS blended with increasing content PEG exhibited lower temperature of glass transition （T） and lower temperature of melting （T） as well as higher melt flow index （MFI）, which indicates the plasticization and proeessability of the composites were dramatically improved. The tensile strength, flexural strength and izod impact strength of PLA/TPS （80/20） increased at first and then decreased with increasing content of PEG due to stronger interfacial adhesion. The optimized mechanical property can be obtained for the blend with 3 wt % PEG. The samples containing PEG after soil burial for 5 months showed quicker degradation being accompanied with large weight loss and mechanical properties loss.

关键词： biodegradation mechanical property polylactic acid starch

The Application of Cellulose Nanocrystals Modified with Succinic Anhydride under the Microwave Irradiation for Preparation of polylactic acid Nanocomposites

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Journal of Renewable Materials 2021年第6期9卷 1127-1142页

作者： Ewa Szefer Agnieszka Leszczyńska Edyta Hebda Krzysztof Pielichowski Department of Chemistry and Technology of Polymers Cracow University of TechnologyKrakow31-155Poland

The aim of this work was to use cellulose nanocrystals that were obtained by hydrolysis in phosphoric acid solution and further modified with succinic anhydride in the microwave field for PLA reinforcement.A series of allbionanocomposites containing unmodified and surface modified cellulose nanocrystals with CNC content in the range of 1–3%_(w.t.) were obtained by melt blending and tested by XRD,SEM,DSC and DMA to investigate the effect of surface esterification of CNCs on the structure,morphology,dynamic mechanical properties of bionanocomposites,as well as phase transitions of PLA in the presence of cellulosic *** investigations showed the highest increase of storage modulus by ca.7%(335 MPa at 25℃)in the glassy state of PLA for 2%_(w.t.)of unmodified ***,addition of 2%_(w.t.)of succinylated CNCs caused the highest increase of the onset of glass transition temperature(by 6.2℃)thus widening the temperature range of biocomposite *** increase of glass transition temperature indicates the strongest interfacial interactions due to improved miscibility of surface modified nanocrystals and thus good dispersion of additive in PLA matrix providing high interface.

关键词： Cellulose nanocrystals CNC whiskers surface modification succinic anhydride PLA polylactic acid nanocomposites

polylactic acid Nanoparticles Targeted to Brain Microvascular Endothelial Cells

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Journal of Huazhong University of Science and Technology(Medical Sciences) 2005年第6期25卷 642-644页

作者：王华芳胡豫孙望强谢长生 Institute of Hematology Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China Nano Pharmaceutical Research Center Huazhong University of Science & Technology Wuhan 430074 China

In this work, blank polylactic acid （PLA） nanoparticles with unstained surface were prepared by the nano-deposition method. On the basis of the preparation, the effect of surface modification on brain microvascular endothelial cells （BMECs） targeting was examined by in vivo experiments and fluorescence microscopy. The results showed that PLA nanoparticles are less toxic than PACA nanoparticles but their BMECs targeting is similar to PACA nanoparticles. The experiments suggest that drugs can he loaded onto the particles and become more stable through adsorption on the surface of PLA nanoparticles with high surface activity. The surface of PLA nanoparticles was obviously modified and the hydrophilicity was increased as well in the presence of non-ionic surfactants on PLA nanoparticles. As a targeting moiety, polysobate 80 （T-80） can facilitate BMECs targeting of PLA nanoparticles.

关键词： polylactic acid nanoparticles, polysorbate brain microvascular endothelial cells targeting