Hardwood residue(HR),a byproduct of paper industry,was liquefied by using polyethylene glycol 400(PEG400) and ethylene carbonate(EC) as the liquefaction solvents,and concentrated sulfuric acid as the catalyst to...Hardwood residue(HR),a byproduct of paper industry,was liquefied by using polyethylene glycol 400(PEG400) and ethylene carbonate(EC) as the liquefaction solvents,and concentrated sulfuric acid as the catalyst to produce bio-polyols(HRLP),which were used to synthesize polyurethane(PU) foams.The effects of conditions on the properties of HRLP and modified PU foams were investigated and the mechanism of biomass liquefaction was discussed.The optimum conditions of liquefaction were obtained as follows: reaction temperature of 160 °C,reaction time of 60 min,ratio of PEG400/EC of 8:2(w/w),and ratio of liquid/solid of 5:1(w/w).The characterization of HRLP modified PU foams suggested that HRLP could partially replace the petroleum polyols to synthesize PU foams.With the increase of the replacement percentage of HRLP,the apparent density and compressive strength of the foams increased firstly,and then decreased.Meanwhile,the thermal stability was improved slightly.展开更多
Objective: To study and compare the hemocompatibility of MWCNTs and hydroxyl modificated MWCNTs (MWCNTs-OH). Methods: MWCNTs and MWCNTs-OH were characterized by scanning electron microscope, Fourier transform infrared...Objective: To study and compare the hemocompatibility of MWCNTs and hydroxyl modificated MWCNTs (MWCNTs-OH). Methods: MWCNTs and MWCNTs-OH were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, water contact angle assays, platelet-adhesion and hemolytic rate assays. Results: The results showed that the two MWCNTs had a similar surface topography and MWCNTs-OH were functionalized with hydroxyl groups on their surfaces. Water contact angle assays indicated that MWCNTs were hydrophobic materials, whereas MWCNTs-OH was hydrophilic. The platelet-adhesion assays displayed that the platelet-adhesion rate of MWCNTs-OH was much lower than MWCNTs. The hemolytic rate assays showed that the hemolytic rates of both MWCNTs were lower than the standard value of 5%. Conclusion: MWCNTs-OH shows superior anticoagulant capacity over MWCNTs. Both MWCNTs and MWCNTs-OH are nonhemolytic materials.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.51503041 and 51472050)
文摘Hardwood residue(HR),a byproduct of paper industry,was liquefied by using polyethylene glycol 400(PEG400) and ethylene carbonate(EC) as the liquefaction solvents,and concentrated sulfuric acid as the catalyst to produce bio-polyols(HRLP),which were used to synthesize polyurethane(PU) foams.The effects of conditions on the properties of HRLP and modified PU foams were investigated and the mechanism of biomass liquefaction was discussed.The optimum conditions of liquefaction were obtained as follows: reaction temperature of 160 °C,reaction time of 60 min,ratio of PEG400/EC of 8:2(w/w),and ratio of liquid/solid of 5:1(w/w).The characterization of HRLP modified PU foams suggested that HRLP could partially replace the petroleum polyols to synthesize PU foams.With the increase of the replacement percentage of HRLP,the apparent density and compressive strength of the foams increased firstly,and then decreased.Meanwhile,the thermal stability was improved slightly.
基金National Natural Science Foundation of Chinagrant number:11075116 and 51272176+3 种基金National Basic Research Program of China(973 Program)grant number:2012CB933604Open Research Fund of the State Key Laboratory of Bioelectronics,Southeast Universitythe Key Laboratory of Beam Technology and Material Modification of the Ministry of Education,Beijing Normal University
文摘Objective: To study and compare the hemocompatibility of MWCNTs and hydroxyl modificated MWCNTs (MWCNTs-OH). Methods: MWCNTs and MWCNTs-OH were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, water contact angle assays, platelet-adhesion and hemolytic rate assays. Results: The results showed that the two MWCNTs had a similar surface topography and MWCNTs-OH were functionalized with hydroxyl groups on their surfaces. Water contact angle assays indicated that MWCNTs were hydrophobic materials, whereas MWCNTs-OH was hydrophilic. The platelet-adhesion assays displayed that the platelet-adhesion rate of MWCNTs-OH was much lower than MWCNTs. The hemolytic rate assays showed that the hemolytic rates of both MWCNTs were lower than the standard value of 5%. Conclusion: MWCNTs-OH shows superior anticoagulant capacity over MWCNTs. Both MWCNTs and MWCNTs-OH are nonhemolytic materials.