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Degradation of poly(butylene adipate-co-terephthalate) by Stenotrophomonas sp. YCJ1 isolated from farmland soil

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Journal of Environmental Sciences 2021年第5期33卷 50-58页

作者： Hao Jia Min Zhang Yunxuan Weng Yao Zhao Chengtao Li Aqsa Kanwal School of Environmental Science and Engineering Shaanxi University of Science and TechnologyXi'an 170021China Beijing Key Laboratory of plastics Health and Safety Quality Evaluation Technology Beijing Technology and Business UniversityBeijing 100048China

In recent years, poly(butylene adipate-co-terephthalate)(PBAT) has been widely used. However, PBAT-degrading bacteria have rarely been reported. PBAT-degrading bacteria were isolated from farmland soil and identified. The effects of growth factors on the degradation of PBAT and the lipase activity of PBAT-degrading bacteria were assessed. The degradation mechanism was analyzed using scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, Xray diffraction, and liquid chromatography-mass spectrometry. The results showed that Stenotrophomonas sp. YCJ1 had a significant degrading effect on PBAT. Under certain conditions, the strain could secrete 10.53 U/m L of lipase activity and degrade 10.14 wt.% of PBAT films. The strain secreted lipase to catalyze the degradation of the ester bonds in PBAT, resulting in the production of degradation products such as terephthalic acid, 1,4-butanediol, and adipic acid. Furthermore, the degradation products could participate in the metabolism of YCJ1 as carbon sources to facilitate complete degradation of PBAT, indicating that the strain has potential value for the bioremediation of PBAT in the environment.

关键词： Biodegradable Poly(butylene adipate-co-terephthalate)(PBAT) Stenotrophomonas sp. Lipase Degradation mechanism

Efficient Thermal Stabilization of Polyvinyl Chloride with Tannin-Ca Complex as Bio-Based Thermal Stabilizer

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Materials Sciences and Applications 2015年第5期6卷 360-372页

作者： Hussein A. Shnawa Moayad N. Khalaf Yousef Jahani Abed Alameer H. Taobi Chemistry department College of Science University of Basrah Basrah Iraq department of plastics Faculty of Processing Iran Polymer and Petrochemical Institute Tehran Iran

The potential use of tannin-Ca complex derived from tannins as bio-based thermal stabilizer and antioxidant additive for polyvinyl chloride (PVC) was investigated in this work. For this project, Reapak B-NT/7060 was applied as reference thermal stabilizer. Variable compositions: (1, 2, and 3) part per hundred ratio (phr) of tannin-Ca complex in the presence of 10 phr Dioctyl phthalate (DOP) as plasticizer in all PVC formulations were prepared by melt mixing by internal mixer at 165°C. Tannin-Ca complex was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) analysis as well as by means of differential scanning calorimetry (DSC). The tannin derivative stabilization efficiency under inert atmosphere was determined by using thermogravimetric analysis (TGA). In addition, its thermal stabilization effect has been assessed in air as oxidizing atmosphere by DSC in dynamic conditions. According to TGA thermograms, the initial degradation temperature (Ti) and optimum degradation temperature (Top?) for the main degradation stage of PVC stabilized with this derivative were about 280°C and 310°C, respectively. While these were about 255°C and 293°C, respectively for PVC stabilized with commercial thermal stabilizer. Global results of TGA, DSC, SEM and EDX show that the tannin-Ca complex provides the best properties and results in stabilizing both against thermal degradation and thermal oxidation degradation of PVC.

关键词： PVC Natural Polyphenols Tannin-Calcium Complex Bio-Based Thermal Stabilizer

Biocatalytic Synthesis of Fluorescent Conjugated Polyserotonin

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Journal of Renewable Materials 2019年第2期7卷 205-214页

作者： Weeradech Kiratitanavit Ferdinando F.Bruno Zhiyu Xia Shiran Yu Jayant Kumar Ramaswamy Nagarajan department of plastics Engineering University of Massachusetts LowellLowell01854USA Soldier Protection and Survivability Directorate US Army Combat Capabilities Development Command Soldier CenterNatick01760USA Center for Advanced Materials University of Massachusetts LowellLowell01854USA.4Department of Physics&Applied PhysicsUniversity of Massachusetts LowellLowell01854USA department of Physics&Applied Physics University of Massachusetts LowellLowell01854USA

Polyserotonin was enzymatically synthesized using Horseradish peroxidase(HRP)as the *** novel conjugated polymer exhibited good fluorescent properties with significantly higher Stokes shift than its *** enzymatic polymerization eliminated the need for extensive purification of the product(typically necessary for the removal of residual metal catalyst)allowing the product to be naturally fluorescent as *** reaction was monitored using UV-Vis spectrophotometry and the polymers were characterized using Fluorescence,Fourier Transform Infrared Spectroscopy(FTIR)and *** possibility of using polyserotonin for the detection of nitro-aromatic compounds,including 2,4-dinitrotoluene(DNT)and trinitrotoluene(TNT),through fluorescence quenching at parts per million levels in solution has also been demonstrated.

关键词： Polyserotonin enzymatic polymerization fluorescence sensing

Tannin-Ca Complex as Green Thermal Stabilizer Additive for PVC: Viscoelastic Properties

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Open Journal of Organic Polymer Materials 2015年第3期5卷 69-78页

作者： Hussein A. Shnawa Yousef Jahani Moayad N. Khalaf Abed Alamer H. Taobi Chemistry department College of Science University of Bsarh Basrah Iraq department of plastics Faculty of Processing Iran Polymer and Petrochemical Institute Tehran Iran

This study investigated the viscoelastic and rheometeric properties of PVC stabilized with tannin-Ca complex as totally bio-based thermal stabilizer. Dynamic mechanical thermal analysis (DMTA) used to characterize the viscoelastic properties of PVC samples obtained by thermal mixing of PVC with three composition percentages (1.0, 2.0, and 3.0) part per hundred ratios (phr) of tannin-Ca complex with this polymer. The torque rheometery test used to monitor the effect of tannins derivative on the thermal stability and mixing properties of PVC formulations during samples processing. For that purpose, PVC sample with 2 phr commercial thermal stabilizer (Reapak B-NT/ 7060) was used for comparison and considered as reference samples. Before the glass transition temperature of PVC at 30°C - 60°C, the DMTA curves show that the values of storage modulus and tan delta of PVC samples stabilized with tannin derivative were very similar with those of PVC sample stabilized with commercial thermal stabilizer. The glass transition temperature (Tg) of PVC stabilized with commercial thermal stabilizer and with tannin-Ca complex occurred at about 76°C. In a sequence, after the glass transition region of PVC samples, the DMTA scans confirmed that the PVC samples with 2 phr tannin-Ca complex have relatively longer flowing stage which occurs at lower temperatures by 18°C per that of PVC sample stabilized with commercial stabilizer. Global results of the torque rheometery which have suitable plateau stages and the DMTA show that the processing thermal stability and thermal flexibility of PVC are clearly increased with the incorporation of tannin-Ca complex. All the PVC formulations with tannins-Ca complex show excellent viscoelastic properties which were found to be slightly best or much closed to those obtained for PVC stabilized with commercial thermal stabilization.

关键词： PVC Viscoelastic Properties Tannin-Ca Complex Thermal Stability Tg

Synthesis and Characterization of 2,6-Bis(imino)phenoxy Cobalt Complexes

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Chinese Journal of Chemistry 2002年第12期20卷 1523-1528,1461页

作者：韩玲芹孙文华王乐勇邵长星王宏根李记太 State /üy Laboratory of Engineering plastics and The Center for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China department of Chemistry Hebei University Baoding Hebei 071002 China State Key Laboratory of Functional Polymer Nankai University Tianjin 300071 China Email: Wen-Hua Sun (whsun@***)

A series of cobalt complexes bearing 2,6-bis(imino) phenoxy ligands, LCoCl2 [L = 2,6-(ArNCH)2CH3C6H2OH] was synthesized by the reaction of the ligand 2,6-bis (imino) phenol with the equivalent mole of cobalt dichloride, and these complexes were characterized by elemental analyses, 1H NMR, MS and IR spectra. The structure of one complex was determined by single crystal X-ray diffraction analysis.

关键词： cobalt complex Schiff-base crystal structure

Synthesis of PP-g-PIP and Properties of PP/PP-g-PIP Binary Blends

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Chinese Journal of Polymer Science 2017年第4期35卷 569-580页

作者： Cai-jun Zhu Lei Li Yi-nan He He Huang Qian Li Wei Yuan 李化毅郑水蓉 You-liang Hu department of Applied Chemistry School of Natural and Applied SciencesNorthwestern Polytechnical University Research and Development Center of Shenhua Ningxia Coal Industry Group Co. Ltd. Beijing National Laboratory of Molecular Sciences Chinese Academy of Sciences Key Laboratory of Engineering PlasticsJoint Laboratory of Polymer Science and MaterialsInstitute of ChemistryChinese Academy of Sciences

The polypropylene-grafl-polyisoprene （PP-g-PIP） copolymers with different side chain length were synthesized by the combination of solid phase graft and anionic polymerization. The copolymers were characterized by nuclear magnetic resonance spectrum （1H-NMR）, gel permeation chromatography （GPC） and differential scanning calorimetry （DSC）. Five PP/PP-g-PIP blends with PP-g-PIP as a flexibilizer to toughen PP were prepared and characterized by scanning electron microscope （SEM）, dynamic mechanical analysis （DMA）, DSC, wide-angle X-ray diffraction （WAXD）. Their morphologies, glass transition temperatures, crystallinity and mechanical properties were investigated. All the results pointed out that the covalent bonding of PP and PIP increased the compatibility and interfacial adhesion, which led to PIP well dispersed in the system and small size PIP particles in the binary blends. In addition, the toughness of PP was improved while its tensile strength slightly decreased.

关键词： Polypropylene Polypropylene-graft-polyisoprene Binary blend Mechanical property Morphology

Natural Products Diversity of Marine Ascidians(Tunicates;Ascidiacea)and Successful Drugs in Clinical Development

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Natural Products and Bioprospecting 2017年第1期7卷 1-111页

作者： Satheesh Kumar Palanisamy N.M.Rajendran Angela Marino department of Chemical BiologicalPharmaceutical and Environmental ScienceUniversity of Messina98166 MessinaItaly Key Laboratory of Engineering plastics and Beijing National Laboratory for Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeijing 100190China

This present study reviewed the chemical diversity of marine ascidians and their pharmacological applications,challenges and recent developments in marine drug discovery reported during 1994–2014,highlighting the structural activity of compounds produced by these *** date only 5%of living ascidian species were studied from\3000 species,this study represented from family didemnidae(32%),polyclinidae(22%),styelidae and polycitoridae(11–12%)exhibiting the highest number of promising *** to 580 compound structures are here discussed in terms of their occurrence,structural type and reported biological ***-cancer drugs are the main area of interest in the screening of MNPs from ascidians(64%),followed by anti-malarial(6%)and remaining *** approved ascidian compounds mechanism of action along with other compounds status of clinical trials(phase 1 to phase 3)are discussed here *** review highlights recent developments in the area of natural products chemistry and biotechnological approaches are emphasized.

关键词： Cancer Cytotoxicity Diversity Metabolites Pharmacology

The role ofγ-C_(2)H_(5)NO_(2) as a new transient liquid phase in cold sintering process of BaTiO_(3) composites

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Journal of Advanced Ceramics 2024年第7期13卷 942-955页

作者： Jitrawan Noisak Pimchanok Ieamviteevanich Thitirat Charoonsuk Phakkhananan Pakawanit Nattapong Pinpru Wanwilai Vittayakorn Tosapol Maluangnont Panpailin Seeharaj Theerachai Bongkarn Te-Wei Chiu Naratip Vittayakorn Advanced Materials Research Unit School of ScienceKing Mongkut’s Institute of Technology LadkrabangBangkok 10520Thailand department of Chemistry School of ScienceKing Mongkut’s Institute of Technology LadkrabangBangkok 10520Thailand department of Materials Science Faculty of ScienceSrinakharinwirot UniversityBangkok 10110Thailand Synchrotron Research and Applications Division Synchrotron Light Research InstituteNakhon Ratchasima 30000Thailand Sustainability Centre Plastics Market Intelligent DepartmentPlastics Institute of ThailandBangkok 10110Thailand Electroceramics Research Laboratory College of Materials Innovation and TechnologyKing Mongkut's Institute of Technology LadkrabangBangkok 10520Thailand department of Physics Faculty of ScienceNaresuan UniversityPhitsanulok 65000Thailand Research Center for Academic Excellence in Applied Physics Faculty of ScienceNaresuan UniversityPhitsanulok 65000Thailand department of Materials and Mineral Resources Engineering "National"Taipei University of TechnologyTaipei 106TaiwanChina

Dielectric materials,such as barium titanate(BT)-based materials,have excellent dielectric properties but require high temperatures(above 1300℃)for ceramic fabrication,leading to high costs and energy *** cold sintering process(CSP)offers a solution to these issues and is gaining worldwide attention as an innovative fabrication *** this work,we proposed an alternative organic ferroelectric phase,gamma-glycine(γ-GC),which acts as a transient liquid phase to fabricate high-density composites with barium titanate(BT)at low temperatures through *** findings show that the density of 15γ-GC/85BT reached 96.7%±1.6%when it was sintered at 120℃for 6 h under 10 MPa uniaxial *** electron microscopy‒energy dispersive X-ray spectroscopy(SEM‒EDS)mappings of the composite suggested thatγ-GC completely underwent the precipitation-dissolution process and,therefore,filled between BT ***,X-ray diffraction(XRD)and Fourier-transform infrared spectroscopy(FTIR)confirmed the preservation ofγ-GC without undesired phase *** addition,the ferroelectric and dielectric properties ofγ-GC/BT composites have been *** high dielectric constant(ε_(r))was 3600,and the low dielectric loss(tanδ)was 1.20 at 200℃and 100 kHz for the 15γ-GC/85BT *** hysteresis loop showed a remanent polarization(P_(r))of 0.55µC·cm^(−2)and a coercive field(E_(c))of 7.25 kV·cm^(−1).Our findings reaffirmed that an organic ferroelectric material(γ-GC)can act as a transient liquid phase in a CSP that can successfully and sustainably fabricateγ-GC/BT composites at low temperatures while delivering outstandingly high performance.

关键词： gamma-glycine(γ-GC) barium titanate(BT) cold sintering process organic ferroelectric materials dielectric properties ferroelectric properties

PARTIALLY DISENTANGLEMENT OF MONO-DISPERSED POLYPROPYLENE AND ITS PROPERTY IN THE MELT

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PARTIALLY DISENTANGLEMENT OF MONO-DISPERSED POLYPROPYLENE AN...