检索结果-南通市图书馆

Chinese Journal of Polymer Science 1995年第4期13卷 289-314页

作者： Kam W.Leong 毛海泉卓仁禧 Department of Biomedical Engineering School of Medicine The Johns Hopkins University Baltimore MD 21205 USA Department of Chemistry Wuhan University Wuhan 430072

This review provides a glimpse of the potential of the biodegradable phos-phoryl-containing polymers in medical applications. Undoubtedly these polymerspossess unique properties that are yet to be fully understood. Many areas warrantfurther investigation and much optimization remains to be done. The fascinatingchemistry of phosphorus poses interesting hurdles but at the same time leavesample room for polymer scientists to exercise their creativity in designinginteresting biomaterials. As the mutual understanding between basic and clinicalscientists on the need of medical devices and the capabilities of these newbiomaterials expands, imaginative application of new biomaterials to other medi-cal applications can be expected.

关键词： biodegradable polymers phosphoryl-containing backbone controlled drug delivery

Stereoselective synthesis of biodegradable polymers by salen-type metal catalysts

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2022年第11期65卷 2096-2121页

作者： Xi Liao Ya Su Xiaoyan Tang Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenter for Soft Matter Science and EngineeringCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

biodegradable polymers are a promising sustainable alternative to conventional petroleum-based polymers and have attracted recent extensive research interest due to their potential environmental friendliness and sustainability. Among them, aliphatic polyesters and polycarbonates are the most extensively studied ones. The metal-catalyzed ring-opening polymerization(ROP) of cyclic esters and ring-opening copolymerization(ROCOP) of epoxides with anhydrides or CO_(2) are often considered to be the classic and efficient methods to synthesize stereoregular polymers. Moreover, the versatile salen-type metal complexes have been used to prepare almost all types of biodegradable polymers with excellent stereoselectivity control. Hence, this review focuses on stereoselective synthesis of biodegradable polymers by salen-type metal catalysts developed in the last *** polyesters from ROP of cyclic esters, ROCOP of epoxides with cyclic anhydrides, and carbonylative polymerization of epoxides, as well as aliphatic poly(thio)carbonate from ROCOP of epoxides with CO_(2) or COS are discussed in detail. This review highlights the polymerization mechanisms, catalyst characteristics, and factors controlling the stereoselectivity of each polymerization reaction, aiming to provide general rules for the future design of stereoselective catalysts.

关键词： stereoselective ring-opening(co)polymerization salen-based metal complexes biodegradable polymers polyesters poly(thio)carbonates

7-Oxa-2,3-Diazanorbornene:A One-Step Accessible Monomer for Living Ring-Opening Metathesis Polymerization to Produce Backbone-biodegradable polymers

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2024年第9期6卷 2305-2317页

作者： Xiaoyang Wang Yixing Wen Yu Wang Wei Li Xueguang Lu Wei You Beijing National Laboratory for Molecular Sciences(BNLMS) CAS Key Laboratory of Engineering PlasticsInstitute of ChemistryChinese Academy of SciencesBeijing 100190 Beijing National Laboratory for Molecular Sciences(BNLMS) CAS Key Laboratory of ColloidInterface and Chemical ThermodynamicsInstitute of ChemistryChinese Academy of SciencesBeijing 100190 University of Chinese Academy of Sciences Beijing 100049

Traditional ring-opening metathesis polymerization(ROMP)reactions exhibit broad functional group compatibility and precise control over polymer architectures,albeit with non-biodegradable *** progress has resulted in a series of biodegradable ROMP products with diverse cleavable functional groups,yet the majority of the monomers display moderate to low ring strain,which restricts their living polymerization *** this study,a novel category of readily available 7-oxa-2,3-diazanorbornenes(ODAN)is presented,which exhibits the highest ring strain(22.8 kcal/mol)compared to existing degradable ROMP *** trait endows ODAN with the ability to perform living polymerization reactions,generating narrowly dispersed homopolymers,block copolymers,and statistical copolymers with various cyclic olefin comonomers,thereby enabling precise control over distribution of the biodegradable functional ***,the resultant polymers comprise directly connected allyl hemiaminal ether and urethane units,which are hydrolyzable at controllable ***,these well-defined,structure-tunable,and backbone-biodegradable ROMP polymers are applied as nanoetching materials and biodegradable delivery carriers.

关键词： biodegradable polymers ring-opening metathesis polymerization living polymerization nanoetching materials high ring strain

WAXD and FTIR Studies of Electron Beam Irradiated biodegradable polymers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Physical Science and Application 2012年第4期2卷 80-87页

作者： Yasko Kodama Nelson Batista de Lima Clfiudia Giovedi Luci Diva Brocardo Machado Wilson Aparecido Parejo Calvol Akihiro Oishi Kazuo Nakayama Radiation Technology Center Nuclear and Energy Research Institute (IPEN-CNEN/SP) Sao Paulo 05508-000 Brazil Science and Materials Technology Center Nuclear and Energy Research Institute (IPEN-CNEN/SP) Sao Paulo 05508-000Brazil Navy Technological Center in Sao Paulo (CTMSP) Sao Paulo 05508-000 Brazil Research Institute for Innovation in Sustainable Chemistry National Institute of Advanced Industrial Science and Technology(AIST) Ibaraki 3058565 Japan

Poly（L-lactic acid）（PLLA） and poly（e-caprolactone）（PCL） have been receiving much attention lately due to their biodegradability in human body as well as in the soil, also due to their biocompatibility, environmentally friendly characteristics and non-toxicity. Morphology of biodegradable polymers affects the rate of their biodegradation. A polymer that has high degree of crystallinity will degrade at a slower rate due to the inherent increased stability. PCL homopolymer crosslinking degree increases with increasing doses of high energy radiation. On the other hand, the irradiation ofPLLA homopolymer promotes mainly chain-scissions at doses below 250 kGy. In the present work, twin screw extruded films of PLLA and PCL biodegradable homopolymers and 50：50 （w：w） blend were electron beam irradiated using electron beam accelerator Dynamitron （E = 1.5 MeV） from Radiation Dynamics, Inc. at doses in the range of 50 kGy to 103 kGy in order to evaluate the effect of electron beam radiation. Wide-angle X-ray diffraction （WAXD） patterns of non irradiated and irradiated samples were obtained using a diffractometer Rigaku Denki Co. Ltd., Multiflex model; and Fourier transform infrared spectroscopy （FTIR） spectra was obtained using a NICOLET 4700, attenuated total reflectance （ATR） technique. By WAXD patterns of as extruded non irradiated and irradiated PLLA it was verified broad diffusion peaks corresponding to amorphous polymer. There was a slight increase of the mean crystallite size of PCL homopolymer with increasing radiation dose. PCL crystalline index （CI） decreased with radiation dose above 500 kGy. But then, PLLA CI increased with radiation dose above 750 kGy. From another point of view, PLLA presence on the 50：50 blend did not interfere on the observed mean crystallite size increase up to 250 kGy. From 500 kGy to 103 kGy the crystallite size of PCL was a little bigger in the blend than the homopolymer. In contrast, FTIR results have shown that this technique was not sen

关键词： biodegradable polymers PLLA PCL electron beam WAXD FTIR.

Wood Plastic Composites Prepared from biodegradable Poly（butylene succinate） and Burma Padauk Sawdust （Pterocarpus macrocarpus）： Water Absorption Kinetics and Sunlight Exposure Investigations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2017年第4期14卷 781-790页

作者： Nawadon Petchwattana Jakkid Sanetuntikul Paranee Sriromreun Borwon Narupai Division of Polymer Materials Technology Faculty of Agricultural Product Innovation and Technology Srinakharinwirot University Ongkharak Nakhon Nayok 26120 Thailand Faculty of Engineering and Technology King Mongkut's University of Technology North Bangkok Bankhai Rayong 21120 Thailand Department of Chemical Engineering Faculty of Engineering Srinakharinwirot University Ongkharak Nakhon Nayok 26120 Thailand Expert Centre of Innovative Materials Thailand Institute of Scientific and Technological Research Pathum Thani 12120 Thailand

Wood plastic biocomposites of biodegradable poly（butylene succinate）（PBS） and Padauk sawdust was successfully pre- pared by using a twin screw extruder and an injection molding machine. The effects of water absorption and sunlight exposure on some properties of the composites were investigated. Water absorption of PBS composites was found to follow the Fick＇s law of diffusion, while the diffusion coefficient increased with increasing wood content. Maximum water absorption of around 4.5% was observed at 30 wt.% sawdust. Optical micrograph indicated the swelling of wood particles by around 1% - 3% after 30 days of water immersion. The tensile and flexural strengths reduced slightly both under the water immersion and sunlight exposure. After 90 days of exposure, the composites clearly looked paler than the non-weathered ones. Thermal scan indicated the re- duction of crystalline region due to the plasticization effect derived from water molecules.

关键词： wood plastic composites biodegradable polymers Fickian diffusion mechanical properties environmental deg-radation

biodegradable Poly(butylene adipate-co-terephthalate)/Poly(glycolic acid) Films: Effect of Poly(glycolic acid) Crystal on Mechanical and Barrier Properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第7期41卷 1123-1132页

作者： Hong-Wei Pan Ye Wang Shi-Ling Jia Yan Zhao Jun-Jia Bian Hui-Li Yang Yan-Ping Hao Li-Jing Han Hui-Liang Zhang Key Laboratory of Polymer Ecomaterials Chinese Academy of SciencesChangchun Institute of Applied ChemistryChangchun130022China School of Pharmaceutical Sciences Changchun University of Chinese MedicineChangchun130117China Changchun University of Technology Changchun130012China Shandong Dawn Polymer Co. Ltd.Longkou265700China

Binary biodegradable polymers films, poly(butylene adipate-co-terephthalate)(PBAT) and poly(glycolic acid)(PGA), were prepared through batch melt mixing to obtain Film Ⅰ and Film Ⅱ under two different processing conditions. PGA crystals played a major role in enhancing the mechanical and barrier properties of the films. For Film Ⅰ, there were initial PGA crystals before the film blowing process, the PGA molecular chain further crystallized, forming the oriented crystallization of PGA. Moreover, the Xcand crystalline size in Film Ⅰ were higher than those in Film Ⅱ. Compared with the different processing methods, Film Ⅰ has excellent mechanical and oxygen barrier properties due to the crystallization and orientation. The tensile strength reached 45.0 MPa, and tear strength exceeded 138.2 kN/m, while the elongation at break was as high as 750% for PBAT/PGA 85/15 in Film Ⅰ. The WVTR, WVP coefficients, and OP coefficients of PBAT/PGA films were decreased obviously with increasing the PGA content both in Film Ⅰ and Film Ⅱ. Moreover, the barrier properties of oxygen in Film Ⅰ were better than that in Film Ⅱ. This work reveals a feasible processing technique by introducing of initial crystallization of PGA to blow PBAT/PGA films with excellent mechanical and barrier properties.

关键词： Poly(butylene adipate-co-terephthalate) Poly(glycolic acid)(PGA) biodegradable polymers Films

Study on the Properties of Esterified Corn Starch/Polylactide biodegradable Blends

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2022年第11期10卷 2949-2959页

作者： Yongjie Zheng Mingjian Xu Jingzhi Tian Meihong Yu BinTan Hong Zhao YinTang College of Chemistry and Chemical Engineering Qiqihar UniversityQiqihar161006China Engineering Research Center of Flax Processing Technology Ministry of Education P.R.CQiqihar UniversityQiqihar161006China College of Light Industry and Textile Qiqihar UniversityQiqihar161006China Department of Chemical Engineering and Materials Science Michigan State UniversityEast Lansing48824USA

Fully bio-based and biodegradable starch/polylactic acid blends have received increasing attentions for their biodegradability and potential to offset the use of unsustainable fossil resources,specifically,their application in ***,corn starch was first esterified with maleic anhydride and then compounded with polylactide(PLA)to prepare esterified corn starch/polylactic acid blends with starch content up to 35 wt%.The structures,morphologies,thermal and mechanical properties of starch or blends were *** results showed that corn starch was successfully grafted with maleic anhydride,which showed increased crystallinity and particle size than native *** corn starch/polylactic acid blends showed good surficial compatibility and good thermal stability with main decomposition temperature in the range of 300℃to 400℃.Additionally,incorporation of corn starch increased the hydrophilicity and water uptake of ***,the tensile and flexural strengths of blends decreased with increasing esterified starch amount.

关键词： biodegradable polymers corn starch polylactide composite

Anti-migratory and increased cytotoxic effects of novel dual drug-loaded complex hybrid micelles in triple negative breast cancer cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2015年第8期8卷 2533-2547页

作者： Rajaletchumy Veloo Kutty Chor Yong Tay Chen Siew Lim Si-Shen Feng David Tai Leong Department of Chemical and Biomolecular Engineering National University of Singapore 4 Engineering Drive Singapore 117585 Singapore International Joint Cancer Institute The Second Military Medical University 800 Xiang Yin Road Shanghai 200433 China NUS Graduate School for Integrative Science and Engineering National University of Singapore 28 Medical Drive Singapore 117456 Singapore

A polymer-based nanocarrier was developed for the co-delivery of epigenetic and chemotherapeutic drugs. The sterically stabilized hybrid micelle system uses micelles composed of D-a-tocopheryl polyethylene glycol 1000 succinate （vitamin E TPGS or TPGS） and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine- N-[methoxy（polyethylene glycol）-2000] （DSPE-PEG2000）. In this study, suberoylanilide hydroxamic acid （SAHA） and paclitaxel were used as model drugs for combination chemotherapy to enhance therapeutic efficiency in targeting mesenchyme-like triple negative breast cancer （TNBC） cells. Combination therapy of paclitaxel and SAHA in a dual drug micelle system, （P ＋ S）mic, exhibited an IC50 value of 0.52 μg/mL, which is about 5.91-fold more cytotoxic than the mere combination of free drugs （P ＋ S）. Furthermore, the （P ＋ S）mic formulation was far more effective at inhibiting cell migration by more than 3.4-fold than the control. Thus, our findings show that the co-delivery of these drugs using the micelle system greatly enhances their therapeutic effect at a lower dosage, thereby minimizing toxicity. In addition, this formulation is proved to be remarkably effective in preventing cell migration at low dosage.

关键词： nanomedicine biomaterials nanobiology biodegradable polymers drug targeting

Morphological Evaluation of PLA/Soybean Oil Epoxidized Acrylate Three-Dimensional Scaffold in Bone Tissue Engineering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2022年第9期10卷 2391-2408页

作者： Mahmood Hameed Majeed Nabeel Kadhem Abd Alsaheb Department of Biomedical Engineering Al Nahrain UniversityAl Jadriya BridgeBaghdad64074Iraq

Tissue engineering’s main goal is to regenerate or replace tissues or organs that have been destroyed by disease,injury,or congenital *** engineering now uses artificial supporting structures called scaffolds to restore damaged tissues and *** are utilized to attach the right cells and then grow *** prototyping appears to be the most promising technology due to its high level of precision and *** tissue replacement“scaffolding”is a common theme discussed in this *** fused deposition technique was used to construct our scaffold,and a polymer called polylactic acids and soybean oil resin were used to construct our *** samples were then divided into two groups;the first group was left without immersion in the simulated body fluid and served as a control for *** second group was immersed in the simulated body *** results of the Field Emission Scanning Electron Microscope(FESEM),Energy Dispersive X-ray Spectroscopy(EDX)and X-ray diffraction(XRD)were utilized to interpret the surface attachment to ions,elements,and compounds,giving us a new perspective on scaffold *** this study,an innovative method has been used to print therapeutic scaffold that combines fused deposition three-dimensional printing with ultraviolet curing to create a high-quality biodegradable polymeric ***,the results demonstrate that adding soybean oil resin to the PLA increased ion attachment to the surface while also attracting tricalcium phosphate formation on the surface of the scaffold,which is highly promising in bone tissue *** conclusion,the soybean oil resin,which is new in the field of bone tissue engineering,shows magnificent characteristics and is a good replacement biopolymer that replaces many ceramic and polymeric materials used in this field that have poor morphological characteristics.

关键词： Bone tissue engineering polylactic acid soybean oil biodegradable polymers fused deposition modeling scaffold

Tailoring the Properties of Polyhydroxyalkanoates from Plastics to Elastomers via Stereoselective Copolymerizations of rac-β-Butyrolactone and β-Propiolactone

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第9期42卷 963-972页

作者： Haoran Zhang JiaojiaoQin Xiaoyan Tang Beijing National Laboratoryfor Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenterfor Soft Matter Science and EngineeringCollegeof Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Poly(3-hydroxybutyrate),a crucial member of the large biodegradable polyhydroxyalkanoate family,suffers from its *** enhance its performance,we employed a straightforward approach involving the ring-opening copolymerization of racemic-β-butyrolactone(rac-β-BL)andβ-propiolactone(β-PL)using the syndio-selective amino-alkoxy-bis(phenolate)-yttrium complex as a catalyst,thanks to the excellent ductility of poly(3-hydroxypropionate).Control over the rac-β-BL/β-PL feeding ratios and polymerization time yielded random or block copolymers with tunable thermal and mechanical properties comparable to traditional fossil-based ***,we achieved one-pot synthesis of hard-soft-hard triblock copolymers by exploiting monomers’different copolymerization rates and a bifunctional initiator,thus transforming polyhydroxyalkanoates from hard and tough plastics to soft and ductile thermoplastic elastomers.

关键词： Ring-opening(co-)polymerization biodegradable polymers Polyhydroxyalkanoates Copolymers Plastics Elastomers