最新刊期
卷 ， 期 11 ， 2013
- 摘要：Using supercritical carbon dioxide (Sc-CO2) as the physical foaming agent,polystyrene (PS) foams were prepared in a batch process via two different heating modes and depressurization.The cellular structures,foam densities and wetting properties of the PS foams were investigated by means of scanning electron microscope,electronic balance and contact angle measuring device,respectively.The results showed that a mono-modal cell structure was obtained only through depressurization,whereas a bi-modal cell structure was achieved through the synergistic effect of heating and depressurization.The large and small cells were formed by nucleation in the heating and depressurization stages,respectively.For the PS foams prepared at 100 ℃ foaming temperature and 30~70 ℃ saturation temperatures,the large and small cells had average diameters of 50~216 and 10~15 m,respectively.Increasing the diameter and density of the large cell was favourable to the decrease of the foam density,and the lowest foam density was 0.15 g/cm3.The mono-modal cell structure yielded an increase in static contact angle (CA) from the intrinsic value of the PS (87.1) to 138.8 on the fractured surface of the foam; the CA value on the surface with a bi-modal cell structure prepared at 70 ℃ saturation temperature increased up to 155.1,displaying the superhydrophobic wetting properties.关键词：Bi-modal cell structure;Supercritical CO2;Foaming;Supersaturation;Superhydrophobicity
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发布时间：2021-03-19 - 摘要：In the presence of pyridine as a catalyst,a bio-based surfactant was synthesized via the alkylation of sodium lignosulfonate (LS) with 1-bromododecane in an alkalic isopropanol/water solution,with the aid of ultrasonic treatment.Structure and property characterization of sodium lignosulfonate (LS),alkylated sodium lignosulfonate without ultrasonication (ALS) and alkylated sodium lignosulfonate with ultrasonication (UALS) were performed by GPC,UV,FTIR and 1H-NMR.The results showed that molecular weight of sodium lignosulfonate decreased from 154200 to 106000 after ultrasonic treatment while the phenolic content of sodium lignosulfonate increased from 0.65% to 1.55%.And the content of methoxy reduced from 36.0% to 21.0% at the same time.The results also showed that the alkylation of sodium lignosulfonate with the aid of ultrasonic treatment was more effective than that of without ultrasonic treatment.The alkylation of sodium lignosulfonate primarily occurred in phenol sites.As a result of the improvement of alkylation,surface activity analysis showed that surface tension of 1% aqueous solution of UALS decreased to 28.2 mN/m,by contrast to 34.1 mN/m of ALS and 41.5 mN/m of LS at the identical concentrations.Crucial micelle concentration of UALS was 510-2g/L,two orders lower than that of LS.Because hydrophobic group was effectively grafted to the macromolecule of sodium lignosulfonate under the influence of ultrasonication,UALS could hold a well-ordered molecular arrangement on the interface between the water and the air.Thus,it showed better surface activity than LS and ALS.And there were two possibly main reasons accounting for the enhancement of alkylating results with the assistance of ultrasonic treatment:on the one hand,it was ascribed to the generation of phenolic groups,and on the other hand,it was attributed to the cleavage of complicated molecular structures of sodium lignosulfonate under the influence of ultrasonication.关键词：Sodium lignosulfonate;Ultrasonic treatment;Alkylation;Characterization;Surface acitivity
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发布时间：2021-03-19 - 摘要：Chitosan-coated magnetic nanoparticles were prepared.At first,surface carboxyl functional magnetic nanoparticles (MNP-COOH) were prepared by co-precipitation.Secondly, chitosan molecules were adsorbed on the surface of particles by electrostatic interaction.The hydroxyl groups on the chitosan were then cross-linked by epichlorohydrin under the protection of primary amine groups with formaldehyde.After the amino-protecting agent were removed,the chitosan coated magnetic nanoparticles with primary amine groups on the surface were obtained.The magnetic nanopartieles were characterized by scanning electron microscopy (SEM),X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR),thermogravimetric analysis (TGA),vibrating sample magnetometry (VSM) and zeta potential analysis.The results showed that the magnetic nanoparticles were coated by chitosan successfully and could be completely dispersed in aqueous solutions of various pH=1~14 to form uniform sols.The magnetic cores of the paritcles are resistent to the corrosion of 0.1 mol/L HCl solution.The diameter of these nanoparticles with the saturation magnetization of 64.5 emu/g distributes between 10 and 20 nm.The remnant magnetization and coercivity of the nanoparticles were nearly zero,suggesting that it possessed a typical superparamagnetic characterization.The isotherm for the adsorption of BSA onto the MNP-CS surface was S-shaped.The maximum adsorption capacity reached 300 mg BSA/g MNP-CS.关键词：Magnetic nanoparticles;Hydrophilic;Chitosan coated;Ferrofluid
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发布时间：2021-03-19 - 摘要：A functional diamine,3,5-diamino-N-(2-octyl-1,3-dioxoisoindolin-5-yl)benzamide (D8) containing imide unit and an assistant diamine monomer 4,4'-dimethyldiphenylmethane (DMMDA) were molecularly designed and synthesized successfully.Polyimides (PIs) containing asymmetric units in the main chain and imide pendant groups were prepared with the copolymerization of DMMDA,D8 and commercial aromatic dianhydride 4,4-oxydiphthalic (ODPA) by chemical imidization.Five PIs were obtained by controlling the mole ratio of diamines and dianhydride.The structures and properties of the resulting co-condensation type PIs were characterized by nuclear magnetic resonance (NMR),Fourier transform infrared spectroscopy (FTIR),gel permeation chromatography (GPC),differential scanning calorimetry (DSC) and ultraviolet analysis (UV-Vis) etc. The PIs obtained were favorably soluble in aprotic polar solvents,such as N-methylpyrrolidone (NMP) and N,N-dimethyl form amide (DMF),and even in common organic solvents such as tetrahydrofunan (THF) and trichloromethane (TCM).The molecular weights of the soluble copolyimides obtained were high and influenced by the mole ratio of the functional diamine monomers.The molecular weights of PIs decreased with the increment of D8.Creasable PI films could be attained by casting from PI solutions.The liquid crystals (LCs) alignment ability of PI films was investigated and the pretilt angles were measured by the crystal rotation method using a pretilt angle tester.It was observed that the pretilt angle increased with the increasing content of functional diamine D8.When the content of D8 was greater than 20%,the PIs obtained high pertilt angles above 89even after five-times rubbing and showed outstanding rubbing-resistant ability.Moreover,the transmittances of the PIs were more than 80%,and their glass transition temperatures were above 260 ℃.This kind of PIs containing imide side chains could be promising materials in vertical-alignment-mode LC displays.关键词：Polyimides;Solubility;Rubbing resistance;Vertical alignment
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发布时间：2021-03-19 - 摘要：The Merrifield resin supported proline-threonine dipeptide catalysts were prepared by solid-phase peptide synthesis (SPPS) and the amino acid incorporation was checked by means of the Kaiser or isatin test.The dipeptide catalyst grafted with the Merrifield resin by the hydroxyl group while keeping free the carboxyl group of L-threonine as the nature proline.Then the catalyst was tested in the Aldol reaction between ketones and aromatic aldehydes.In order to find the optimal reaction conditions for this kind of catalysts,the influence of different conditions was explored,such as solvents,surfactants and the amount of the catalyst.It was found that the surfactant can be used to significantly improve the performance of the catalyst (catalytic activity and stereo-selectivity),and this new peptide-based catalyst could efficiently catalyze the Aldol reaction to provide -hydroxy ketones in good yields with good stereoselectivity.By employing Tween-20 water-soluble micelles as solvent,an medium stereoselectivity was observed at room temperature,up to 14 ∶86 syn. ∶anti.diastereomeric ratio and up to 78% enantiomeric excess.Besides,the immobilized catalyst can be recovered by simple filtration without the need for catalyst regeneration,and it retained catalytic activity and stereochemical reactivity even after being recycled for 4 times.关键词：L-proline;L-threonine;Merrifield resin;Aldol reaction;Asymmetric catalysis
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发布时间：2021-03-19 - 摘要：The phase behaviors of alginate/xanthan mixtures and their influence on the critical gelation of alginate induced by Ca2+ ions were investigated.At a fixed concentration of alginate (0.5 wt%) and with increasing xanthan concentration,the mixtures exhibited compatible,phase separating and liquid crystalline behaviors.The formation of liquid crystals was found to occur at much lower xanthan concentrations in mixtures than that in pure xanthan solution,suggesting that the presence of alginate promoted the formation of xanthan liquid crystals.This was attributed to the increase in the effective concentration of xanthan as a result of segregative phase separation of alginate/xanthan.Via glucono--lactone (GDL)-induced in situ release of Ca2+ from Ca-EDTA,the viscoelastic properties of alginate/xanthan mixtures at different levels of Ca2+ (f =[Ca2+]/[COO-])were measured.Analysis by the Winter-Chambon criteria showed that the critical gel point (fgel) decreased with increasing xanthan concentration.Accompanying phase separation,fgel decreased dramatically while it turned to increase in the liquid crystalline region.Comparison of the relaxation critical exponents obtained from the Winter-Chambon method and relaxation modulus suggested that the addition of xanthan led to the loss of structural self-similarity for alginate gels at the critical points.Phase separation resulted in a more compact critical gel structure whereas liquid crystalline formation made it relatively looser.关键词：Alginate;Xanthan;Mixtures;Gelation;Critical behavior;Fractal dimension
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发布时间：2021-03-19 - 摘要：Poly-tetrahydrofuran (PTHF) with controllable molecular weight was synthesized in cationic ring-opening polymerization of tetrahydrofuran (THF) using phosphotungstic heteropolyacid (HPW)/epichlorohydrin (ECH) as initiator and ethylene glycol (EG) as chain transfer agent.Effects of various factors (polymerization temperature and time,content of ECH,HPW and EG) on the yield and Mn of PTHF product were comprehensively investigated based on a L16(45) orthogonal experimental design.Influence of chain transfer agent EG on THF polymerization was emphatically studied.Thermogravimetric analysis (TGA) was used to examine the weight loss curve of HPW from 25 ℃ to 400 ℃.Infrared spectra (IR),proton nuclear magnetic resonance spectroscopy (1H-NMR) and gel permeation chromatography (GPC) were applied to characterize the terminal molecular structure,molecular weight and its distribution (MWD) of PTHF respectively.It was found that the HPW dried at 170 ℃ for 2 h exhibited the highest activity.The initiator and promotor have synergistic effects on THF polymerization.The addition of EG as chain transfer agent in the cationic ring-opening polymerization of THF can effectively control the chain propagation and depress the back-bitting reaction,which is attributed to the complication competition reaction between EG and THF.In the presence of EG,cyclic fraction obviously diminishes in the resulted PTHF product and the Mn of PTHF product decreases from 12000~23000 to 1100~1700.Also PTHFs MWD is significantly narrowed changing from bimodal distribution into single peak distribution.Moreover PTHFs yield increases from 50% to 80% because of its higher mass transfer efficiency.关键词：Tetrahydrofuran;Cationic ring-opening polymerization;Chain transfer agent;Control of molecular weight;Ethylene glycol
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发布时间：2021-03-19 - 摘要：Viscosity and curing characteristics of polyurethane modified unsaturated polyester (PU-UPES)/color paste mixtures were systematically studied.The results showed that the viscosity of PU-UPES/color paste mixtures tends to increase with the content of the color paste,but the experimental data of viscosity are lower than the theoretical additive data.With the increasing of the color paste content,all of the gelation time,the apparent initial curing temperature and the apparent peak curing temperature increase accordingly,while the apparent final curing temperature and the enthalpy decrease.With the increasing of the heating rate,the curing characteristic temperatures of composite systems shift toward higher temperature values when the composite under the same content of color paste,but the curing enthalpy values are almost constant.Meanwhile,based on the the apparent peak curing temperature at different heating rates,the apparent activation energy and the preexponential factor of PU-UPES/color paste mixture curing reaction can be calculated through the Kissinger equation.The initial curing temperature,the peak curing temperature and the final curing temperature are calculated by the extrapolation method in order to optimize the curing process.Based on the optimum curing process,the adhesion grades of PU-UPES/color paste coatings are above the first level.关键词：Polyurethane modified unsaturated polyester resin;Color Paste;Curing characteristics;Adhesion
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发布时间：2021-03-19 - 摘要：Thermo-sensitive hydrogels based on N-isopropylacrylamide (NIPAM) containing L-amino acid groups were designed and synthesized for chiral resolution.L-tryptophane was used as chiral pool,after esterifization and condensation reactions with acryloyl chloride and the chiral monomer AAc-L-Trp was obtained,and the structure was characterized by IR and 1H-NMR.Then the subsequent copolymerization was carried on between AAc-L-Trp and NIPAM with N,N'-methylenebisacrylamide (MBAA) as linkage agent in the presence of azobisisobutyronitrile (AIBN) in ethanol with different weight ratios.The resulted poly-(NIPAM-co-AAc-L-Trp) hydrogels were identified by IR.The swelling behaviors,deswelling and reswelling kinetics of the chiral hydrogels have been studied,and the results showed that all the poly(NIPAM-co-AAc-L-Trp) hydrogels exhibited evident temperature-sensitivity.Due to the hydrophobicity of chiral monomer incorporated into the structure of the chiral gels,the thermo-sensitivity of the chiral gels is lower than that of PNIPAM gel,and the lower critical solution temperature (LCST) decreased with increasing of the contents of chiral monomer.The chiral adsorption and separation performance were also investigated using D/L-phenylalanine (D/L-Phe) as a model.The results indicated that compared with PNIPAM gel,the chiral gels performed higher adsorption rate and larger adsorption quantities for D-Phe enantiomers.Increasing the contents of chiral monomer or the temperature will improve the efficiency of resolution of DL-Phe.关键词：Thermo-sensitive hydrogel;N-isopropylacrylamide;L-Tryptophane;Synthesis;Chiral recognization
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发布时间：2021-03-19 - 摘要：In order to obtain functionalized PET lms with thermosensitive surface,thermoresponsive polymer,poly(N-iso-propylacrylamide) (PNIPAM) was grafted from the surface of PET films via surface initiated atom transfer radical polymerization (SI-ATRP).Polar groups of carboxyl were produced on the surface of PET lms through alkaline hydrolysis and oxidation,then the ATRP initiator was immobilized on the surface of PET lms.And the ATRP was carried out at 30 ℃ in the presence of CuCl as a catalyst,ME6TREN as a ligand,and (30 ∶70,V/V) acetone/H2O as a reaction medium.The composition,structure and morphology of the surface of PET film and modified PET films were characterized by attenuated total reflection Fourier transform infrared spectroscopy (FTIR/ATR),X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM).And the surface properties of modified PET films were studied by contact angle measurements.The data showed that the structure and composition of the polyester film were changed after grafting,which demonstrated the successfully grafting of PNIPAM from the surface of PET films.Further more,with the increase of the reaction time,the grafting rate on the film surface increased,the grafting density increased to 0.239 mg/cm2 when the polymerization time was 16 h.It suggests that the SI-ATRP is a living radical polymerization.And the PET films modified by PNIPAM layers were stimulus-responsive with temperature indicating the successful functionalization of PET films.关键词：PET film;Surface-initiated atom transfer radical polymerization (SI-ATRP);Functionalization;Thermosensitive
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发布时间：2021-03-19 - 摘要：By using FeSO4/K2S2O8 as the initiator of radical reaction,octamethacryl polyhedral oligomeric silsesquioxane coated multi-walled carbon nanotube (PMMA-POSS/MWNT) hybrids were synthesized under homogeneous and heterogeneous polymerization systems,respectively.Transmission electron microscopy (TEM) revealed the PMMA-POSS coated MWNT hybrids with uniform thickness were obtained under the homogeneous system.The thickness of PMMA-POSS layers coated on MWNT can be controlled from 15~25 to 35~50 nm through controlling the relative usage of MMA-POSS.The shape of coated PMMA-POSS changed to microspheres which suspended on the surface of MWNT in the heterogeneous systems.The PMMA-POSS/MWNT hybrids were characterized by using Fourier transform infrared spectroscopy (FTIR),Raman spectroscopy (Raman) and thermal gravimetric analysis (TGA).Through the Raman characterization,the interaction between the MMA-POSS and the MWNT was also proven.Thermal gravimetric analysis (TGA) revealed the amount of the coated MMA-POSS on the surface of the MWNT,when the thickness of coated layers was more than 35 nm,the mass loss was near 45%.The promise of synthesizing gram-scale functionalized MWNT from a wide range of polymers in a small volume of solvent may greatly improve the ability to engineer novel MWNT composites.关键词：Carbon nanotubes;Polyhedral oligomeric silsesquioxane;Coating;Radical
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发布时间：2021-03-19 - 摘要：Siloxy-terminated fluoroelastomers were prepared through two-step reactions:(1) pentafluorophenol ester-terminated fluoroelastomer was synthesized by Steglich reaction using liquid carboxyl-terminated fluoroelastomer and pentafluorophenol as raw material; (2) the siloxy-terminated fluoroelastomer was prepared by substitution reaction with -aminopropyl triethoxysilane.The chemical structure of liquid carboxyl-terminated fluoroelastomer,pentafluorophenol ester-terminated fluoroelastomer and siloxy-terminated fluoroelastomers was characterized by FTIR,1H-NMR,19F-NMR and GPC.The carboxyl content measurement of pentafluorophenol ester-terminated fluoroelastomer was carried out by automatic potentiometric titration,and the conversion reaction is above 99.9%,which indicates that the reaction was completely conducted.The Siloxy-terminated fluoroelastomer can be cured at room temperature according to the mechanism of moisture-cure.Cured siloxy-terminated fluoroelastomer films with low Tg is usually obtained from higher molecular weight of fluoroelastomer.The cross-linked films obtained from higher molecular weight of fluoroelastomer have better tensile strength and elongation at break.The cured films have excellent chemical resistance,such as acid resistance,jet fuel oil resistance and cyclohexane resistance.And the cured films with higher molecular weight have better chemical resistance than those of the lower molecular weight.The observed contact angles were 91~114 for water and 89~111 for glycerol,which indicates that the cured films have good hydrophobic and hydrophilic properties.It is seen that the initial temperature (T5) of cured films appears in the range of 215 to 280 ℃ and the char yield at elevated temperature of 800 ℃ remains at 23.44%~38.69%.关键词：Siloxy-terminated fluoroelastomers;Pentafluorophenol ester-terminated fluoroelastomers;Carboxyl-terminated fluoroelastomers;Cure;Physical and chemical properties
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发布时间：2021-03-19 - 摘要：The sulfonated poly (aryl ether ketone sulfone) copolymers bearing pendant amino groups were synthesized by nucleophilic polycondensation method in this paper.The C-Am-SPAEKS crosslinked membrane was obtained by a heating reaction at 180 ℃.The FTIR spectrum and1H-NMR spectrum showed that the amino group had been introduced into the SPAEKS copolymer and the amide bond between the amino and the sulfonic acid groups was formed.The results indicated that the covalent crosslinking between the amino and the sulfonic acid groups decreased the methanol permeability and the swelling ratio,improved the thermal stability and water retention capacity of the C-Am-SPAEKS crosslinked membrane.The proton conductivity of the C-Am-SPAEKS crosslinked membrane reached 0.0883 S/cm at 120 ℃ which is able to meet the requirements of proton exchange membrane fuel cells.The methanol permeability of the C-Am-SPAEKS crosslinked membrane was only 0.510-7cm2/s at 25℃,which was much lower than that of SPAEKS membrane (8.910-7 cm2/s) and Nafion (210-6 cm2/s) under the same test conditions.All the results indicate that the C-Am-SPAEKS crosslinked membrane is promising as proton exchange membranes for middle-high temperature proton exchange membrane fuel cells applications and direct methanol fuel cells.关键词：Amino;Sulfonated poly(aryl ether ketone sulfone);Proton exchange membrane;Crosslinked membrane
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发布时间：2021-03-19 - 摘要：A new polymerizable anthraquinone dye,1-(m-(2-(2-(acryloxyl)ethoxyl)ethylsulfonyl) anilino)anthraquinone (AVSAQ),was designed and synthesized via multiple reactions,and then copolymerized with styrene (St),butyl acrylate (BA) and methacrylic acid (MAA) by semi-continuous emulsion polymerization to fabricate the covalently colored P(St-BA-MAA-AVSAQ) latex.The chemical structure of AVSAQ,the properties of the P(St-BA-MAA-AVSAQ) latexes and their latex films were characterized,and the influences of the AVSAQ and ammonium persulfate (APS) on the monomer conversion and the colloidal properties of the latexes were investigated.Results showed that the emulsion polymerization performed smoothly with AVSAQ amount equal to or less than 4.0 wt% and APS amount equal to or more than 0.5 wt% based on the total monomers,and the average hydrodynamic diameter of the latex particle was about 60 nm.Both the conversion of the total monomers and the conversion of AVSAQ decreased with increasing amount of AVSAQ,and when AVSAQ amount reached 4.0 wt%,the conversion of the total monomers and AVSAQ was 95.0% and 93.6%,respectively.The UV-Vis spectrum of the covalently colored P(St-BA-MAA-AVSAQ) was as same as that of AVSAQ with max 486.8 nm.Comparing with the non-covalently colored polymer latex,P(St-BA-MAA-AVSAQ) latex exhibited advanced storage stability and color retention,and the latex film possessed excellent fastness towards light and solvent.关键词：Polymerizable anthraquinone dye;Emulsion polymerization;Stability;Light fastness
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发布时间：2021-03-19 - 摘要：Superparamagnetic Fe3O4 nanoparticles were synthesized by chemical coprecipitation method with FeCl36H2O and FeCl24H2O as raw materials,followed by the modification of their surfaces with oleic acid and sodium undecylenate,and a stable water-based magnetic fluid with solid content of 4% was obtained.The seed microspheres were prepared through soap-free emulsion polymerization with the existence of magnetic fluid,using styrene (St) and glycidyl methacrylate (GMA) as the monomers.Then core-shell magnetic fluorescent microspheres were prepared through soap-free seeded emulsion polymerization in the presence of seeded microspheres,using styrene (St),sodium 4-vinyl benzenesulfonate (NaSS) and rare earth complexes Eu(AA)3Phen as functional monomer,the microspheres exhibit excellent magnetic properties as well as fluorescent properties.The structure,morphology,magnetic and fluorescent properties of the microspheres were characterized by X-ray diffraction (XRD),transmission electron microscopy (TEM),photon correlation spectroscopy (PCS),Fourier transform infrared spectroscopy (FTIR),vibrating sample magnetometer (VSM) and fluorescence spectroscopy.It was indicated that seed microspheres and magnetic fluorescent microspheres showed good monodispersity,with the average particle diameter of 147 nm and 228 nm respectively,TGA analysis showed that the Fe3O4 content of magnetic fluorescent microspheres was 4.7%,corresponding to a saturation magnetization of 0.396 emu/g,and characteristic emission spectra of rare earth Eu3 + were observed at 595 nm and 619 nm.关键词：Rare earth complexes;Soap-free seeded emulsion polymerization;Magnetic fluorescent microsphere
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发布时间：2021-03-19 - 摘要：This work aims at developing a strategy to synthesize functional cyclic copolyesters,based on the living ring-opening polymerization and the intra-molecular cross-linking reaction by UV irradiation.First,-chlorocyclohexanone was converted into -chloro--caprolactone (ClCL) in the presence of m-chloroperoxybenzoic acid (mCPBA) by the Baeyer-Villiger oxidation.Second,the quantitative polymerization of a mixture of CL and the functional monomer ClCL was initiated in toluene by 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP) to obtain a precursor,i.e.,a living cyclic copolyesters (LCP(CLcoClCL)).The molecular weight of the precursor can be controlled by varying the molar ratio of monomer to initiator.When the comonomers were converted completely,a fresh feed of -(1-acryloyloxyethyl)--caprolactone (AECL) was added to the polymerization medium to achieve living cyclic copolyesters,poly((CLcoClCL)-b-(AECL)).Finally,the functional cyclic copolyester which is stable and free of tin dialkoxides,i.e.,cP(CLcoClCL) (Mn,NMR=32400),was synthesized by the intramolecular photo cross-linking of few acrylic unsaturations in the close vicinity of the living cyclic chain under UV irradiation.The structures and properties of the polymers were characterized by SEC,NMR and DSC technologies.The characterization by SEC and viscosity showed that the hydrodynamic volumes of the functional cyclic copolyesters were smaller than those of their linear counterparts.DSC study showed that both the melting point and degree of crystallinity of the functional random copolyesters decreased upon cyclization.The strategy herein proposed has been successfully tested for the synthesis of cyclic copolyesters with high molecular weight and high efficiency.关键词：Ring-opening polymerization reaction;Functional cyclic random copolyesters;Cyclic poly(-caprolactone-co--chloro--caprolactone);Intramolecular cross-linking reaction
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发布时间：2021-03-19
Research Article
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