This study focuses on the improvement of the thermal stability and flame-retardant performance of polyurethane(PU)foam by using effective flame-retardant additives and nano silica(nSiO_(2))particles from rice husk.The...This study focuses on the improvement of the thermal stability and flame-retardant performance of polyurethane(PU)foam by using effective flame-retardant additives and nano silica(nSiO_(2))particles from rice husk.The addition of non-halogen flame retardants(FRs)including aluminum trihydroxide(ATH),triphenyl phosphate(TPP),and diammonium phosphate(DAP)leads to markedly enhanced thermal sta-bility and fire resistance of the PU/nSiO_(2)/FRs nanocomposites,resulting in achieving UL-94 HB standard.In particular,the nanocomposites met the UL-94 V-0 criteria thanks to the inclusion of DAP at 25 phr.The LOI value of the nanocomposites reached 26%which is much higher than that of PU/nSiO_(2)nanocompos-ite,about 20%.In order to further understand the fire-proof mechanism,the residue char layer remaining of the PU/nSiO_(2)/FRs nanocomposites after being burned was also investigated by scanning electron mi-croscopy(SEM)and Fourier transform infrared(FTIR).In addition,the microstructure,thermal stability,thermal conductivity,and mechanical properties of nanocomposites were also evaluated in this study.展开更多
The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L N...The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L NaCl solutions. EIS results were compared with gravimetric measurements on the freestanding films. The amount of water absorption showed great discrepancy between the two methods. The diffusion coefficient in the polyurethane film with P/B：30% was the smallest among those filled with nano-TiO2 pigments. The dielectric constant ε of the polyurethane varnish film obtained from the initial capacitance was in the range of typical values of polymers. SEM was used to measure the distribution of nano-TiO2 particles in the polyurethane films.展开更多
A series of nano silica/silicone modified waterborne polyurethane(WPU) have been synthesized from polytetramethylene glycol and isophorone diisocyanate, dihydroxymethyl propionic acid and triethylamine, ethylenediamin...A series of nano silica/silicone modified waterborne polyurethane(WPU) have been synthesized from polytetramethylene glycol and isophorone diisocyanate, dihydroxymethyl propionic acid and triethylamine, ethylenediamine, trimethylolpropane, nano-SiO2 and the silane coupling agent KH550. The effect of the dosage of nano-SiO2 on the WPU-Si membrane and the coated RDX(cyclotrimethylenetrinitramine) particles have been studied in terms of their surface properties, mechanical properties, and thermal stability. The results showed that with the increase of Si content, the stability of the emulsion reduced gradually. The material with more Si content displayed an increased thermodynamic stability, an increased high temperature resistance, an increased tensile strength and a decreased elongation at break. With the increase of Si content, the surface tension of the material decreased, the bibulous rate reduced, and the contact angle increased gradually, so that the surface tension of the polyurethane and RDX are close to each other which could improve the performance of coating.展开更多
CO2-copolymer based polyurethane foams were synthesized and characterized in this paper. The foams were found to have higher strength and lower heat of combustion than the conventional polyether polyurethane foams. ...CO2-copolymer based polyurethane foams were synthesized and characterized in this paper. The foams were found to have higher strength and lower heat of combustion than the conventional polyether polyurethane foams. They may find wide applications in many fields.展开更多
The waterborne polyurethane/doped Ti O2 nanoparticle hybrid films were prepared. Nd, I doped Ti O2 was prepared with a 50 nm particle size firstly. The hybrid film was prepared by mixing doped Ti O2 with waterborne po...The waterborne polyurethane/doped Ti O2 nanoparticle hybrid films were prepared. Nd, I doped Ti O2 was prepared with a 50 nm particle size firstly. The hybrid film was prepared by mixing doped Ti O2 with waterborne polyurethane, followed by heat treatment. The presence and nanometric distribution of doped Ti O2 nanoparticles in prepared membranes is evident according to SEM images. The photocatalytic activities of doped Ti O2 were signifi cantly enhanced compared with pure Ti O2 powders. After the hybrid fi lm fabrication, the photocatalytic activities were almost the same as the pure catalysts with kMB of 0.046. In the antibacterial testing, the hybrid fi lms can inhibit E. coli growth. A signifi cant decrease in membrane fl uidity and increase of permeability of E. coli were observed.展开更多
High solid content CO_(2)-based cationic waterborne polyurethanes(CWPUs)were prepared using CO_(2)-polyols as soft segment and Nmethyl diethanolamine(MDEA)as hydrophilic group.The resulting stable aqueous dispersion d...High solid content CO_(2)-based cationic waterborne polyurethanes(CWPUs)were prepared using CO_(2)-polyols as soft segment and Nmethyl diethanolamine(MDEA)as hydrophilic group.The resulting stable aqueous dispersion displayed a high solid content of 52%with a low MDEA loading of 3.52 wt%.This novel structural CWPU can provide excellent adhesive strength,whose T-peel strength could reach 173.48N/5cm,20%higher than that of ester-based cationic waterborne polyurethane(87.55 N/5cm).The CO_(2)-based CWPU film showed only 2 wt%swelling percentage after 240 min immersion in water,and no change was observed during its immersion in 5 wt%sodium hydroxide solution.The tensile strength of CO_(2)-WPUs dropped slowly to 91.2%after 480 min immersion in a 5 wt%sodium hydroxide solution,whereas that of esterbased CWPUs dropped quickly to 32%after 240 min and their mechanical properties were lost after 360 min immersion.Meanwhile,the retention of the tensile strength of the CO_(2)-CWPUs was 81.5%even after 720 min immersion in 10 wt%H_(2)O_(2) solution,while it was only ca.38%for the ester-based CWPUs.These results indicated that the cationic CO_(2)-based CWPU may be promising waterborne adhesive with outstanding ageing resistance due to its synergistic effect from carbonate and ether groups of CO_(2)-polyol structure.展开更多
The performance of a biofilter for off-gas treatment relies on the activity of microorganisms and adequate O_2 and H_2O. In present study, a microelectrode was applied to analyze O_2 in polyurethane foam cubes（PUFCs...The performance of a biofilter for off-gas treatment relies on the activity of microorganisms and adequate O_2 and H_2O. In present study, a microelectrode was applied to analyze O_2 in polyurethane foam cubes（PUFCs） packed in a biofilter for SO_2 removal. The O_2 distribution varied with the density and water-containing rate（WCR） of PUFCs. The O_2 concentration dropped sharply from 10.2 to 0.8 mg/L from the surface to the center of a PUFC with 97.20%of WCR. The PUFCs with high WCR presented aerobic–anoxic–aerobic areas.Three-dimensional simulated images demonstrated that the structure of PUFCs with high WCR consisted of an aerobic ＂shell＂ and an anoxic ＂core＂, with high-density PUFCs featuring a larger anoxic area than low-density PUFCs. Moreover, the H_2O distribution in the PUFC was uneven and affected the O_2 concentration. Whereas aerobic bacteria were observed in the PUFC surface, facultative anaerobic microorganisms were found at the PUFC core, where the O_2 concentration was relatively low. O_2 and H_2O distributions differed in the PUFCs, and the distribution of microorganisms varied accordingly.展开更多
Optically active polyurethane was synthesized by the polyaddition of (2R, 3R)-(+)-diethyl L-tartrate (DET), 4,4'-diphenylmethane diisocyanate (MDI) and polyethylene glycol (PEG) with various molecular weights at 6...Optically active polyurethane was synthesized by the polyaddition of (2R, 3R)-(+)-diethyl L-tartrate (DET), 4,4'-diphenylmethane diisocyanate (MDI) and polyethylene glycol (PEG) with various molecular weights at 60 degrees C in DMSO. The polymers were characterized by specific rotation, DSC and H-1 NMR spectra.展开更多
Silane coupling agent KH560 was used to modify the surface of nano-α-Al<sub>2</sub>O<sub>3</sub> in ethanol-aqueous solution with different proportions. The particle size of nano-α-Al<sub&...Silane coupling agent KH560 was used to modify the surface of nano-α-Al<sub>2</sub>O<sub>3</sub> in ethanol-aqueous solution with different proportions. The particle size of nano-α-Al<sub>2</sub>O<sub>3</sub> was determined by nano-particle size analyzer, and the effects of nano-α-Al<sub>2</sub>O<sub>3</sub> content, ethanol-aqueous solution ratio and KH560 dosage on the dispersion and particle size of nano-α-Al<sub>2</sub>O<sub>3</sub> were investigated. The material structure before and after modification was determined by Fourier transform infrared spectroscopy (FTIR). Aqueous polyurethane resin and inorganic components are combined with modified nano-α-Al<sub>2</sub>O<sub>3</sub> dispersion to form chromium-free passivation solution. The solution is coated on the galvanized sheet, the adhesion and surface hardness are tested, the bonding strength of the coating and the surface hardness of the substrate are discussed. The corrosion resistance and surface morphology of the matrix were investigated by electrochemical test, neutral salt spray test and scanning electron microscope test. The chromium-free passivation film formed after the modification of nano-α-Al<sub>2</sub>O<sub>3</sub> increases the surface hardness of galvanized sheet by about 85%. The corrosion resistance of the film is better than that of a single polyurethane film. The results show that the surface hardness and corrosion resistance of polyurethane resin composite passivation film are significantly improved by the introduction of nano-α-Al<sub>2</sub>O<sub>3</sub>.展开更多
A novel and facile method toward a series of yellow water-borne polyurethane was developed by using an intrinsically colored diol in this paper.The yellow aqueous dispersion PCLD-HENA-PU was synthesized based on isoph...A novel and facile method toward a series of yellow water-borne polyurethane was developed by using an intrinsically colored diol in this paper.The yellow aqueous dispersion PCLD-HENA-PU was synthesized based on isophorone diisocyanate(IPDI), polycaprolactonediol(PCLD) and 2,2-dimethylol propionic acid(DMPA) using a yellow diol N,N-bis(2-hydroxyethyl)-4-nitroaniline (HENA) as a chain extender.Due to the complete reaction of OH group in colorant HENA with NCO group in diisocyanate,a series of stable yellow p...展开更多
In order to prepare hydrophobic waterborne polyurethane coatings with better performances,the silicon-containing waterborne polyurethane(SiWPU)with functional chain extender hydroxyethyl acrylate(HEA)was prepared firs...In order to prepare hydrophobic waterborne polyurethane coatings with better performances,the silicon-containing waterborne polyurethane(SiWPU)with functional chain extender hydroxyethyl acrylate(HEA)was prepared first,and then a series of silicon&fluorine-containing polyurethane/acrylate(FSiPUA)emulsions were obtained with flourine containing acrylic monomer by seed emulsion polymerization,introducing micro-nano SiO2 into FSiPUA emulsion to make the final hybrid emulsion.The properties of Si WPU,FSiPUA and SiO2/FSiPUA were investigated by fourier transform infrared spectra(FTIR),transmission electron microscope(TEM),Scanning Electron Microscope(SEM)and some other analytical methods.The results revealed that FSiPUA emulsion particles possessed composite core-shell structure and FSiPUA films with suitable ratio performed better than Si WPU films in hardness,water resistance and solvent resistance.The SiO2/FSiPUA films with micro-nano dual roughness structure showed a water contact angle of 136°with good resistance to acid and alkali.展开更多
In this work,a degradable polyurethane composed of caprolactone(CL)and L-Lactide(LLA)as soft segments,and 4,40-methylenebis(cyclohexyl isocyanate)(H12 MDI)and polytetramethylene ether glycol(PTMEG)as hard segments,was...In this work,a degradable polyurethane composed of caprolactone(CL)and L-Lactide(LLA)as soft segments,and 4,40-methylenebis(cyclohexyl isocyanate)(H12 MDI)and polytetramethylene ether glycol(PTMEG)as hard segments,was prepared.Hydrolytic degradation experiment revealed that the degradable polyurethane(PU)could be degraded in artificial seawater.It also showed that caprolactone-copolyurethane(CL-PU)copolymer with higher crystallinity degraded much slower in artificial seawater.However,the introduction of LLA resulted in an increase in the hydrophilicity and reduction in the crystallinity of degradable PU,as demonstrated by the contact angle analysis.The result of the scanning electron microscope showed that the surface of degradable PU renewed under static condition.Moreover,degradable PU was able to be used as a carrier,and it controlled the release rate of 4,5-dichloro-2-octyl-isothiazolone(DCOIT).The anti-diatom(Navicula incerta)test demonstrated that the(caprolactone-co-L-lactide)-co-polyurethane 4(CL/LAx-PU4)with DCOIT contents prevented the adhesion of diatom Navicula incerta(88.37%reduction)due to their self-polishing and the release of antifoulants.Therefore,the degradable PU consisted of CL,LLA,and DCOIT could be a durable resin with good antifouling activity for the application in the marine anti-biofouling field.展开更多
The effective and affordable separation of oil and water,a crucial process in the safe han dling of environmental disasters such as crude oil spills and recovery of valuable resources is a highly sought-after yet chal...The effective and affordable separation of oil and water,a crucial process in the safe han dling of environmental disasters such as crude oil spills and recovery of valuable resources is a highly sought-after yet challenging task.Herein,superhydrophobic PU sponge was fab ricated for the fast and cost-effective adsorptive separation of oil and different organic sol vents from water.Octadecyltrichlorosilane(OTS)-functionalized Fe_(3)O_(4)@SiO_(2)core-shell mi crospheres were dip-coated on the surface of porous materials via a dip-coating process thereby endowing them with superhydrophobicity.Owing to the hydrophobic interaction between OTS molecules and oil and increased capillary force in the micropores,the result ing superhydrophobic sponge served as a selective oil-sorbent scaffold for absorbing oil from oil-water mixtures,including oil-water suspensions and emulsions.Remarkably,after the recovery of the adsorbed oil via mechanical extrusion,these superhydrophobic materials could be reused multiple times and maintain their oil-water separation efficacy even afte 10 oil-water separation cycles.展开更多
Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals ...Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals and materials. Poly（propylene carbonate）（PPC） is an emerging CO_2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive（RHMPA） based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics（PC, PMMA, ABS） and metals（aluminium, steel）, which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process（up to 270 °C）. The study is expected to expand the applications of PPC and provide a new type of CO_2-based renewable and eco-friendly materials.展开更多
基金funded by the Vietnam National University Ho Chi Minh City(VNU-HCM)under grant number C2022-18-41.
文摘This study focuses on the improvement of the thermal stability and flame-retardant performance of polyurethane(PU)foam by using effective flame-retardant additives and nano silica(nSiO_(2))particles from rice husk.The addition of non-halogen flame retardants(FRs)including aluminum trihydroxide(ATH),triphenyl phosphate(TPP),and diammonium phosphate(DAP)leads to markedly enhanced thermal sta-bility and fire resistance of the PU/nSiO_(2)/FRs nanocomposites,resulting in achieving UL-94 HB standard.In particular,the nanocomposites met the UL-94 V-0 criteria thanks to the inclusion of DAP at 25 phr.The LOI value of the nanocomposites reached 26%which is much higher than that of PU/nSiO_(2)nanocompos-ite,about 20%.In order to further understand the fire-proof mechanism,the residue char layer remaining of the PU/nSiO_(2)/FRs nanocomposites after being burned was also investigated by scanning electron mi-croscopy(SEM)and Fourier transform infrared(FTIR).In addition,the microstructure,thermal stability,thermal conductivity,and mechanical properties of nanocomposites were also evaluated in this study.
基金supported by the National Natural Science Foundation of China(No.50499334)
文摘The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L NaCl solutions. EIS results were compared with gravimetric measurements on the freestanding films. The amount of water absorption showed great discrepancy between the two methods. The diffusion coefficient in the polyurethane film with P/B：30% was the smallest among those filled with nano-TiO2 pigments. The dielectric constant ε of the polyurethane varnish film obtained from the initial capacitance was in the range of typical values of polymers. SEM was used to measure the distribution of nano-TiO2 particles in the polyurethane films.
基金the financial support by the National Natural Science Foundation of China(No.20973022 and No.11472048)
文摘A series of nano silica/silicone modified waterborne polyurethane(WPU) have been synthesized from polytetramethylene glycol and isophorone diisocyanate, dihydroxymethyl propionic acid and triethylamine, ethylenediamine, trimethylolpropane, nano-SiO2 and the silane coupling agent KH550. The effect of the dosage of nano-SiO2 on the WPU-Si membrane and the coated RDX(cyclotrimethylenetrinitramine) particles have been studied in terms of their surface properties, mechanical properties, and thermal stability. The results showed that with the increase of Si content, the stability of the emulsion reduced gradually. The material with more Si content displayed an increased thermodynamic stability, an increased high temperature resistance, an increased tensile strength and a decreased elongation at break. With the increase of Si content, the surface tension of the material decreased, the bibulous rate reduced, and the contact angle increased gradually, so that the surface tension of the polyurethane and RDX are close to each other which could improve the performance of coating.
基金This project was supported by the National Natural Science Foundation of China(No.20274053).
文摘CO2-copolymer based polyurethane foams were synthesized and characterized in this paper. The foams were found to have higher strength and lower heat of combustion than the conventional polyether polyurethane foams. They may find wide applications in many fields.
基金Funded by the National Natural Science Foundation of China(No.51208141)Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.QA201206)
文摘The waterborne polyurethane/doped Ti O2 nanoparticle hybrid films were prepared. Nd, I doped Ti O2 was prepared with a 50 nm particle size firstly. The hybrid film was prepared by mixing doped Ti O2 with waterborne polyurethane, followed by heat treatment. The presence and nanometric distribution of doped Ti O2 nanoparticles in prepared membranes is evident according to SEM images. The photocatalytic activities of doped Ti O2 were signifi cantly enhanced compared with pure Ti O2 powders. After the hybrid fi lm fabrication, the photocatalytic activities were almost the same as the pure catalysts with kMB of 0.046. In the antibacterial testing, the hybrid fi lms can inhibit E. coli growth. A signifi cant decrease in membrane fl uidity and increase of permeability of E. coli were observed.
基金financially supported by the National Natural Science Foundation of China(No.32071686)。
文摘High solid content CO_(2)-based cationic waterborne polyurethanes(CWPUs)were prepared using CO_(2)-polyols as soft segment and Nmethyl diethanolamine(MDEA)as hydrophilic group.The resulting stable aqueous dispersion displayed a high solid content of 52%with a low MDEA loading of 3.52 wt%.This novel structural CWPU can provide excellent adhesive strength,whose T-peel strength could reach 173.48N/5cm,20%higher than that of ester-based cationic waterborne polyurethane(87.55 N/5cm).The CO_(2)-based CWPU film showed only 2 wt%swelling percentage after 240 min immersion in water,and no change was observed during its immersion in 5 wt%sodium hydroxide solution.The tensile strength of CO_(2)-WPUs dropped slowly to 91.2%after 480 min immersion in a 5 wt%sodium hydroxide solution,whereas that of esterbased CWPUs dropped quickly to 32%after 240 min and their mechanical properties were lost after 360 min immersion.Meanwhile,the retention of the tensile strength of the CO_(2)-CWPUs was 81.5%even after 720 min immersion in 10 wt%H_(2)O_(2) solution,while it was only ca.38%for the ester-based CWPUs.These results indicated that the cationic CO_(2)-based CWPU may be promising waterborne adhesive with outstanding ageing resistance due to its synergistic effect from carbonate and ether groups of CO_(2)-polyol structure.
基金financially supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No.2010ZX07319-001-03)the National Natural Science Foundation of China(No.51221892)
文摘The performance of a biofilter for off-gas treatment relies on the activity of microorganisms and adequate O_2 and H_2O. In present study, a microelectrode was applied to analyze O_2 in polyurethane foam cubes（PUFCs） packed in a biofilter for SO_2 removal. The O_2 distribution varied with the density and water-containing rate（WCR） of PUFCs. The O_2 concentration dropped sharply from 10.2 to 0.8 mg/L from the surface to the center of a PUFC with 97.20%of WCR. The PUFCs with high WCR presented aerobic–anoxic–aerobic areas.Three-dimensional simulated images demonstrated that the structure of PUFCs with high WCR consisted of an aerobic ＂shell＂ and an anoxic ＂core＂, with high-density PUFCs featuring a larger anoxic area than low-density PUFCs. Moreover, the H_2O distribution in the PUFC was uneven and affected the O_2 concentration. Whereas aerobic bacteria were observed in the PUFC surface, facultative anaerobic microorganisms were found at the PUFC core, where the O_2 concentration was relatively low. O_2 and H_2O distributions differed in the PUFCs, and the distribution of microorganisms varied accordingly.
基金the Natural Science Foundation of Shaanxi Province，the Special Foundation of the Education Department of Shaanxi Province，the Special Research Fund of Xianyang Normal University for Talent Introduction
基金Project 29774039 was supported by the National Natural Science Foundation of China.
文摘Optically active polyurethane was synthesized by the polyaddition of (2R, 3R)-(+)-diethyl L-tartrate (DET), 4,4'-diphenylmethane diisocyanate (MDI) and polyethylene glycol (PEG) with various molecular weights at 60 degrees C in DMSO. The polymers were characterized by specific rotation, DSC and H-1 NMR spectra.
文摘Silane coupling agent KH560 was used to modify the surface of nano-α-Al<sub>2</sub>O<sub>3</sub> in ethanol-aqueous solution with different proportions. The particle size of nano-α-Al<sub>2</sub>O<sub>3</sub> was determined by nano-particle size analyzer, and the effects of nano-α-Al<sub>2</sub>O<sub>3</sub> content, ethanol-aqueous solution ratio and KH560 dosage on the dispersion and particle size of nano-α-Al<sub>2</sub>O<sub>3</sub> were investigated. The material structure before and after modification was determined by Fourier transform infrared spectroscopy (FTIR). Aqueous polyurethane resin and inorganic components are combined with modified nano-α-Al<sub>2</sub>O<sub>3</sub> dispersion to form chromium-free passivation solution. The solution is coated on the galvanized sheet, the adhesion and surface hardness are tested, the bonding strength of the coating and the surface hardness of the substrate are discussed. The corrosion resistance and surface morphology of the matrix were investigated by electrochemical test, neutral salt spray test and scanning electron microscope test. The chromium-free passivation film formed after the modification of nano-α-Al<sub>2</sub>O<sub>3</sub> increases the surface hardness of galvanized sheet by about 85%. The corrosion resistance of the film is better than that of a single polyurethane film. The results show that the surface hardness and corrosion resistance of polyurethane resin composite passivation film are significantly improved by the introduction of nano-α-Al<sub>2</sub>O<sub>3</sub>.
基金the National Natural Science Foundation of China(No.50273035)
文摘A novel and facile method toward a series of yellow water-borne polyurethane was developed by using an intrinsically colored diol in this paper.The yellow aqueous dispersion PCLD-HENA-PU was synthesized based on isophorone diisocyanate(IPDI), polycaprolactonediol(PCLD) and 2,2-dimethylol propionic acid(DMPA) using a yellow diol N,N-bis(2-hydroxyethyl)-4-nitroaniline (HENA) as a chain extender.Due to the complete reaction of OH group in colorant HENA with NCO group in diisocyanate,a series of stable yellow p...
基金Funded by the National High Technology Research and Development Program("863"Program)(No.2003AA305071)
文摘In order to prepare hydrophobic waterborne polyurethane coatings with better performances,the silicon-containing waterborne polyurethane(SiWPU)with functional chain extender hydroxyethyl acrylate(HEA)was prepared first,and then a series of silicon&fluorine-containing polyurethane/acrylate(FSiPUA)emulsions were obtained with flourine containing acrylic monomer by seed emulsion polymerization,introducing micro-nano SiO2 into FSiPUA emulsion to make the final hybrid emulsion.The properties of Si WPU,FSiPUA and SiO2/FSiPUA were investigated by fourier transform infrared spectra(FTIR),transmission electron microscope(TEM),Scanning Electron Microscope(SEM)and some other analytical methods.The results revealed that FSiPUA emulsion particles possessed composite core-shell structure and FSiPUA films with suitable ratio performed better than Si WPU films in hardness,water resistance and solvent resistance.The SiO2/FSiPUA films with micro-nano dual roughness structure showed a water contact angle of 136°with good resistance to acid and alkali.
基金supported by the National Natural Science Foundation of China(21776249,21878267,21576236)。
文摘In this work,a degradable polyurethane composed of caprolactone(CL)and L-Lactide(LLA)as soft segments,and 4,40-methylenebis(cyclohexyl isocyanate)(H12 MDI)and polytetramethylene ether glycol(PTMEG)as hard segments,was prepared.Hydrolytic degradation experiment revealed that the degradable polyurethane(PU)could be degraded in artificial seawater.It also showed that caprolactone-copolyurethane(CL-PU)copolymer with higher crystallinity degraded much slower in artificial seawater.However,the introduction of LLA resulted in an increase in the hydrophilicity and reduction in the crystallinity of degradable PU,as demonstrated by the contact angle analysis.The result of the scanning electron microscope showed that the surface of degradable PU renewed under static condition.Moreover,degradable PU was able to be used as a carrier,and it controlled the release rate of 4,5-dichloro-2-octyl-isothiazolone(DCOIT).The anti-diatom(Navicula incerta)test demonstrated that the(caprolactone-co-L-lactide)-co-polyurethane 4(CL/LAx-PU4)with DCOIT contents prevented the adhesion of diatom Navicula incerta(88.37%reduction)due to their self-polishing and the release of antifoulants.Therefore,the degradable PU consisted of CL,LLA,and DCOIT could be a durable resin with good antifouling activity for the application in the marine anti-biofouling field.
基金supported by the National Natural Science Foundation of China(Nos.21827815 and 42192571)。
文摘The effective and affordable separation of oil and water,a crucial process in the safe han dling of environmental disasters such as crude oil spills and recovery of valuable resources is a highly sought-after yet challenging task.Herein,superhydrophobic PU sponge was fab ricated for the fast and cost-effective adsorptive separation of oil and different organic sol vents from water.Octadecyltrichlorosilane(OTS)-functionalized Fe_(3)O_(4)@SiO_(2)core-shell mi crospheres were dip-coated on the surface of porous materials via a dip-coating process thereby endowing them with superhydrophobicity.Owing to the hydrophobic interaction between OTS molecules and oil and increased capillary force in the micropores,the result ing superhydrophobic sponge served as a selective oil-sorbent scaffold for absorbing oil from oil-water mixtures,including oil-water suspensions and emulsions.Remarkably,after the recovery of the adsorbed oil via mechanical extrusion,these superhydrophobic materials could be reused multiple times and maintain their oil-water separation efficacy even afte 10 oil-water separation cycles.
基金financially supported by the National Natural Science Foundation of China(Nos.21574019 and 21304015)the Fundamental Research Funds for the Central Universities and the DHU Distinguished Young Professor Program(No.B201303)
文摘Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals and materials. Poly（propylene carbonate）（PPC） is an emerging CO_2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive（RHMPA） based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics（PC, PMMA, ABS） and metals（aluminium, steel）, which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process（up to 270 °C）. The study is expected to expand the applications of PPC and provide a new type of CO_2-based renewable and eco-friendly materials.
