Poly（propylene fumarate-co-propylene sebacate） （P（PF-co-PS）） was crosslinked with Nvinyl pyrrolidone （N-VP） to form networks. It was investigated as biodegradable bone cement. In this paper, P（PF-co-PS） was ...Poly（propylene fumarate-co-propylene sebacate） （P（PF-co-PS）） was crosslinked with Nvinyl pyrrolidone （N-VP） to form networks. It was investigated as biodegradable bone cement. In this paper, P（PF-co-PS） was synthesized and characterized by ^1H-NMR, FTIR and GPC. The effects of the amount of sebacate segments in P（PF-co-PS） main chains and the quantity of N-vinyl pyrrolidone on the in vitro degradation of the polymer networks were examined. Cylindrical specimens were submerged in phosphate buffered saline （PBS） at 37 ℃ and the pH value of PBS is 7.4 for 10 weeks. The gravimetry and compressive mechanical properties were tested over the degradation period. Networks formed by P（PF-oo-PS）8020/N-VP exhibited higher weight loss and better mechanical properties when compared with poly（propylene fumarate）/N-VP networks. The mechanical properties of P（PF-co-PS）/N-VP can be maintained for a very long time, even for 70 days, the yield strength, fracture strength and compressive modulus are （51.78 ± 2.01） MPa, （52.331 ± 1.84） MPa and （957.78 ± 24.40） MPa, respectively. The results demonstrate that the compressive mechanical properties and degradation velocity can be modulated by the amount of crosslinking agents and sebacate segments along the main chains of copolymers.展开更多
A novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) was prepared by cyclic voltammetry (CV) and characterized by FTIR and SEM. It showed good electroactivity for methanol oxidation in H2SO4 solution.
The completely degradable nanocomposites comprised of poly(propylene carbonate)(PPC) and organo-modified rectorite (OREC) were prepared by direct melt intercalation. The structure and mechanical properties of PPC/OREC...The completely degradable nanocomposites comprised of poly(propylene carbonate)(PPC) and organo-modified rectorite (OREC) were prepared by direct melt intercalation. The structure and mechanical properties of PPC/OREC nanocomposites were investigated. The wide-angle X-ray diffraction (WAXD) results show that the galleries distance of OREC is increased after PPC and OREC melt intercalation, which indicates that PPC molecular chain has intercalated into the layers of OREC. The PPC/OREC nanocomposites with lower OREC content show an increase in thermal decomposition temperature compared with pure PPC. The tensile strength and impact strength of PPC/OREC nanocomposites are improved. When the mass fraction of OREC is 4%, the tensile strength and impact strength of the PPC/OREC nanocomposite increase by 22.86% and 48.58% respectively, compared with pure PPC.展开更多
Compared with aqueous single-ion batteries,rechargeable aqueous hybrid ion batteries,especially Li^(+)/Zn^(2+)hybrid ion batteries,are receiving extensive interest owing to their low cost,high operating voltage,and en...Compared with aqueous single-ion batteries,rechargeable aqueous hybrid ion batteries,especially Li^(+)/Zn^(2+)hybrid ion batteries,are receiving extensive interest owing to their low cost,high operating voltage,and energy density.However,their working voltage and lifespan are limited by the decomposition of water and the growth of Zn dendrites.Herein,detrimental side reactions induced by the water reduction and the Zn dendrite growth are successfully suppressed by a poly(propylene glycol)(PPG)-based hybrid ion electrolyte[(1 m Zn(TFSI)2+10 m LiTFSI)in PPG/H2O].The addition of PPG in the electrolyte can not only enhance the bonding strength of hydrogen-bond in water but also tailor the solvation sheath of Zn2+as revealed by synchrotron X-rays.The participated solvation of PPG with Zn^(2+)can weaken Zn-H_(2)O interactions and redistribute Zn^(2+)flux on the surface of the Zn anode,thus inducing favorably even deposition of Zn.In addition,the decomposition of TFSI-contributes a ZnF_(2)-enriched solid electrolyte interface at the Zn anode to further prevent water decomposition and restrain Zn dendrites.The PPG-based electrolyte enables 2.1 V LiMnO_(2)//Zn batteries to deliver high specific capacities(121.7 mAh g^(-1)for a coin cell and 90 mAh g^(-1)for a pouch cell),and maintain 80%of the capacity over 700 cycles at 0.5 C,suggesting a promising pathway for highly reversible aqueous hybrid ion batteries.展开更多
The purpose of the current study is to evaluate the ageing of poly(ethylene-co-propylene) fittings produced by several manufacturers. The fittings were aged for varying times as follows: 0, 2, 13, 23, 45, 106, 225 and...The purpose of the current study is to evaluate the ageing of poly(ethylene-co-propylene) fittings produced by several manufacturers. The fittings were aged for varying times as follows: 0, 2, 13, 23, 45, 106, 225 and 391 days at 100°C. In a previous paper, the oxidation induction time (OItime) and oxidation induction temperature (OItemp) were evaluated with respect to every single step of the ageing process [1]. Here, the Vickers microhardness and wide-angle X-ray line width were used for characterization of the oxidative stability of poly(ethylene-co-propylene) pipes. Both the Vickers microhardness and wide-angle X-ray line width as evaluated from a certain reflex of the diffractogram generally increase with ageing for most samples. The higher microhardness is most likely related to higher fragility of the pipes. The increase of the X-ray line width with ageing indirectly proves that reducing the crystallite size as well as increase of the crystallite defectiveness take place.展开更多
In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom ...In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom transfer radical polymerization(ATRP).The target products were confirmed by GPC and1H NMR.This well-defined copolymer can supply a promising material as drug and gene carriers and protective materials.展开更多
基金Supported by Science Commission of Tianjin (NO.043186011)Outstanding Young Scholarship from NSFC(NO.30125043)+1 种基金the Basic Research Project(NO.2002CCA016500) of the MOSTthe Natural Science Foundation of Tianjin (NO.043803511) .
文摘Poly（propylene fumarate-co-propylene sebacate） （P（PF-co-PS）） was crosslinked with Nvinyl pyrrolidone （N-VP） to form networks. It was investigated as biodegradable bone cement. In this paper, P（PF-co-PS） was synthesized and characterized by ^1H-NMR, FTIR and GPC. The effects of the amount of sebacate segments in P（PF-co-PS） main chains and the quantity of N-vinyl pyrrolidone on the in vitro degradation of the polymer networks were examined. Cylindrical specimens were submerged in phosphate buffered saline （PBS） at 37 ℃ and the pH value of PBS is 7.4 for 10 weeks. The gravimetry and compressive mechanical properties were tested over the degradation period. Networks formed by P（PF-oo-PS）8020/N-VP exhibited higher weight loss and better mechanical properties when compared with poly（propylene fumarate）/N-VP networks. The mechanical properties of P（PF-co-PS）/N-VP can be maintained for a very long time, even for 70 days, the yield strength, fracture strength and compressive modulus are （51.78 ± 2.01） MPa, （52.331 ± 1.84） MPa and （957.78 ± 24.40） MPa, respectively. The results demonstrate that the compressive mechanical properties and degradation velocity can be modulated by the amount of crosslinking agents and sebacate segments along the main chains of copolymers.
文摘A novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) was prepared by cyclic voltammetry (CV) and characterized by FTIR and SEM. It showed good electroactivity for methanol oxidation in H2SO4 solution.
文摘The completely degradable nanocomposites comprised of poly(propylene carbonate)(PPC) and organo-modified rectorite (OREC) were prepared by direct melt intercalation. The structure and mechanical properties of PPC/OREC nanocomposites were investigated. The wide-angle X-ray diffraction (WAXD) results show that the galleries distance of OREC is increased after PPC and OREC melt intercalation, which indicates that PPC molecular chain has intercalated into the layers of OREC. The PPC/OREC nanocomposites with lower OREC content show an increase in thermal decomposition temperature compared with pure PPC. The tensile strength and impact strength of PPC/OREC nanocomposites are improved. When the mass fraction of OREC is 4%, the tensile strength and impact strength of the PPC/OREC nanocomposite increase by 22.86% and 48.58% respectively, compared with pure PPC.
基金the National Natural Science Foundation of China(Grant No.22179044).
文摘Compared with aqueous single-ion batteries,rechargeable aqueous hybrid ion batteries,especially Li^(+)/Zn^(2+)hybrid ion batteries,are receiving extensive interest owing to their low cost,high operating voltage,and energy density.However,their working voltage and lifespan are limited by the decomposition of water and the growth of Zn dendrites.Herein,detrimental side reactions induced by the water reduction and the Zn dendrite growth are successfully suppressed by a poly(propylene glycol)(PPG)-based hybrid ion electrolyte[(1 m Zn(TFSI)2+10 m LiTFSI)in PPG/H2O].The addition of PPG in the electrolyte can not only enhance the bonding strength of hydrogen-bond in water but also tailor the solvation sheath of Zn2+as revealed by synchrotron X-rays.The participated solvation of PPG with Zn^(2+)can weaken Zn-H_(2)O interactions and redistribute Zn^(2+)flux on the surface of the Zn anode,thus inducing favorably even deposition of Zn.In addition,the decomposition of TFSI-contributes a ZnF_(2)-enriched solid electrolyte interface at the Zn anode to further prevent water decomposition and restrain Zn dendrites.The PPG-based electrolyte enables 2.1 V LiMnO_(2)//Zn batteries to deliver high specific capacities(121.7 mAh g^(-1)for a coin cell and 90 mAh g^(-1)for a pouch cell),and maintain 80%of the capacity over 700 cycles at 0.5 C,suggesting a promising pathway for highly reversible aqueous hybrid ion batteries.
文摘The purpose of the current study is to evaluate the ageing of poly(ethylene-co-propylene) fittings produced by several manufacturers. The fittings were aged for varying times as follows: 0, 2, 13, 23, 45, 106, 225 and 391 days at 100°C. In a previous paper, the oxidation induction time (OItime) and oxidation induction temperature (OItemp) were evaluated with respect to every single step of the ageing process [1]. Here, the Vickers microhardness and wide-angle X-ray line width were used for characterization of the oxidative stability of poly(ethylene-co-propylene) pipes. Both the Vickers microhardness and wide-angle X-ray line width as evaluated from a certain reflex of the diffractogram generally increase with ageing for most samples. The higher microhardness is most likely related to higher fragility of the pipes. The increase of the X-ray line width with ageing indirectly proves that reducing the crystallite size as well as increase of the crystallite defectiveness take place.
文摘In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom transfer radical polymerization(ATRP).The target products were confirmed by GPC and1H NMR.This well-defined copolymer can supply a promising material as drug and gene carriers and protective materials.
