用超细疏水性二氧化硅合成五配位有机硅及含硅聚磷腈

以超细疏水性二氧化硅为原料合成五配位有机硅,进一步与六氯环三磷腈反应,合成了含硅聚磷腈.通过红外、热分析等测试手段对合成产物进行了初步分析.热分析研究表明,合成的含硅聚磷腈具有较好的热稳定性,可用于开发新型阻燃剂.     

Preparation and characterization of collagencoclotriphosphazene and its action in flame-retardant viscose fiber

Abstract

In order to develop a flame retardant using the phosphazene derivative of a natural polymer, hexachlorocyclotriphosphazene and collagen were used as the raw materials to synthesize collagencoclotriphosphazene. The Fourier transform infrared results indicate that flame retardant collagencoclotriphosphazene(CGCP) was successfully synthesized. Thermal properties of CGCP were evaluated using thermogravimetry. The thermal analysis shows that the introduction of phosphazene into collagen lowered the primary decomposition temperature, increased the decomposition rate, and caused less weight loss. The viscose fibers blended by CGCP were prepared by the wet spinning method, and the properties of the fiber were investigated. Limiting oxygen index of the flame-retardant fiber containing 12% CGCP was 28.3%, which increased greatly comparing to the fiber sample without CGCP and just decreased slightly to 27.6% after 30 washing cycles. The thermal analysis shows that the introduction of CGCP increased the decomposition rate of viscose fiber at a lower temperature, and caused less weight loss. After burning, the scanning electron microscopy image showed an inflated carbonized coat on the fiber surface. The effect of CGCP on the mechanical properties of the fibers was insignificant. CGCP was compatible with cellulose, and the flame retardancy of the viscose fiber was significantly improved. Due to the introduction of CGCP, moisture regain of the fiber is a little higher than that of viscose fiber.     

Polyphosphazenes—A Promising Candidate for Drug Delivery,Bioimaging, and Tissue Engineering: A Review

Synthetic polymer materials have been surged to the forefront of research in the fields of tissue engineering, drug delivery, and biomonitoring in recent years. Biodegradable synthetic polymers are increasingly needed as transient substrates for tissue regeneration and medicine delivery. In contrast to commonly used polymers including polyesters, polylactones, polyanhydrides, poly(propylene fumarates), polyorthoesters, and polyurethanes, biodegradable polyphosphazenes (PPZs) hold great potential for the purposes indicated above. PPZ's versatility in the synthetic process has enabled the production of a variety of polymers with various physico-chemical, and biological properties have been produced, making them appropriate for biomedical applications. Biocompatible PPZs are often used as scaffolds in the regeneration of skeleton, bones, and other tissues. PPZs have also received special attention as potential drug vehicles of high-value biopharmaceuticals such as anticancer drugs. Additionally, by incorporating fluorophores into the PPZ backbone to produce photoluminescent biodegradable PPZs, the utility of polyphosphazenes is further expanded as they are used in tracking the regeneration of the target tissue as well as the fate of PPZ based scaffolds or drug delivery vehicles. This review provides a summary of the evolution of PPZ applications in the fields of tissue engineering, drug delivery, and bioimaging in recent 5 years.     

聚磷腈的性质、制备及生物医学应用研究进展

聚磷腈是一类新型无机-有机复合功能高分子化合物,具有结构多样性和有机高分子难以比拟的特性,已应用于航空航天、船舶制造、石油化工及生物医学等领域。介绍了聚磷腈的用途、结构、物化性质、制备方法和发展现状。综述其在生物医学方面应用的研究进展情况。     

基于聚磷腈可降解电活性材料的合成及其降解行为研究

以六氯环三磷腈为原料,加热开环聚合制备了聚二氯磷腈,再分别以苯胺五聚体为功能单元、甘氨酸乙酯和赖氨酸为调节基团,通过两步亲核取代反应,合成了两种可用于神经支架工程材料的可降解电活性高分子聚[(甘氨酸乙酯/苯胺五聚体)磷腈](PGAP)和聚[(赖氨酸/苯胺五聚体)磷腈](PLAP)。通过红外、热重、核磁、循环伏安、紫外等对聚合物进行了全面的表征。在此基础上,重点研究了氨基酸类侧链取代基对聚磷腈降解行为的影响。研究结果表明,侧链氨基酸类取代基的类型和比例对此高分子材料的降解行为有着关键性影响。其降解速率随着取代基比例的增加而加快,此外,随着氨基酸侧链基团极性的增加,降解速率增加。     

Novel biodegradable polyphosphazenes containing glycine ethyl ester and benzyl ester of amino acethydroxamic acid as cosubstituents

Novel biodegradable polyphosphazenes containing glycine ethyl ester and benzyl ester of amino acethydroxamic acid as cosubstituents (PGBP) were synthesized by further modifying poly[bis(glycine ethyl ester)phosphazene] (PGP). The polymers were characterized by IR, ¹H‐NMR, DSC, and elemental analysis. Degradation experiments were conducted in vitro at varied pH conditions. The results indicated that the degradation of PGBP was pH‐sensitive. The sample dissoluted after 1.5 days under a physiological condition (pH 7.4) but took more than 20 days under an acidic condition (pH 5–6), which was related to the content of the benzyl ester of amino acethydroxamic acid in the polymer. The “two‐stage” degradation mechanism of PGBP was proposed: that the polymer first degraded to a water‐soluble polymeric product with the fast break of side groups, followed by the relatively slow scission of the backbone. This property of PGBP may be useful in controlled drug‐delivery systems. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2987–2995, 2000     

Conductivity studies of solid polymer electrolytes based on polyethers and polyphosphazene blends

In this work, electrical characteristics of several polymer electrolytes based on polyether and polyphosphazene blends are reported by means of complex impedance spectroscopy. In addition, a statistical analysis was conducted applying a mathematical model to a previously designed pattern to the purpose of gaining insight into the effect exerted on the conductivity of the electrolyte by the portion of each component in the blend. Evidence was obtained to prove that the dependence of conductivity on blend composition adjusts to a reduced cubic model, whose regression coefficients are determined in this work. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2181–2186, 1998     

Polyphosphazene membranes. III. Solid‐state characterization and properties of sulfonated poly[bis(3‐methylphenoxy)phosphazene]

Poly[bis(3‐methylphenoxy)phosphazene] was sulfonated in a solution with SO₃ and solution‐cast into 100–200‐μm‐thick membranes from N,N‐dimethylacetamide. The degree of polymer sulfonation was easily controlled and water‐insoluble membranes were fabricated with an ion‐exchange capacity (IEC) as high as 2.1 mmol/g. For water‐insoluble polymers, there was no evidence of polyphosphazene degradation during sulfonation. The glass transition temperature varied from −28°C for the base polymer to −10°C for a sulfonated polymer with an IEC of 2.1 mmol/g. The equilibrium water swelling of membranes at 25°C increased from near zero for a 0.04‐mmol/g IEC membrane to 900 % when the IEC was 2.1 mmol/g. When the IEC was < 1.0 mmol/g, SO₃ attacked the methylphenoxy side chains at the para position, whereas sulfonation occurred at all available aromatic carbons for higher ion‐exchange capacities. Differential scanning calorimetry, wide‐angle X‐ray diffraction, and polarized microscopy showed that the base polymer, poly[bis(3‐methylphenoxy)phosphazene], was semicrystalline. For sulfonated polymers with a measurable IEC, the 3‐dimensional crystal structure vanished but a 2‐dimensional ordered phase was retained. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 387–399, 1999     

微波法合成含咔唑聚膦腈接枝偶氮硝基苯及其光电导性能研究

采用微波法成功地合成含咔唑聚膦腈接枝偶氮硝基苯,通过UV-Vis、IR、1 H NMR等手段分析了产物的结构并对光电导性质进行了测试。研究表明,微波功率为400W,反应时间为6min,此时产物的产率最高为78.1%(质量分数)。光电导率随着施加电场强度、光强密度和偶氮生色团含量的增加而增强。为制备新型光电材料奠定了基础。     

Novel Proton Conducting Membranes from the Combination of Sulfonated Polymers of Polyetheretherketones and Polyphosphazenes Doped with Sulfonated Single‐Walled Carbon Nanotubes

Intent on developing efficient proton exchange membranes used for direct methanol fuel cells as well as hydrogen fuel cells, a series of membranes based on sulfonated polyetheretherketone and sulfonated polyphosphazene‐graft copolymers is prepared by cross‐linking reaction because the former material has good enough mechanical property, while the latter is excellent in the proton transfer. The cross‐linked membranes combine the advantages of the two kinds of polymers. Among them, the membrane poly[(4‐trifluoromethylphenoxy)(4‐methylphenoxy)phosphazene]‐g‐poly {(styrene)₁₁‐r‐[4‐(4‐sulfobutyloxy)styrene]₃₃‐sulfonated poly(ether ether ketone)75 (CF₃‐PS₁₁‐PSBOS₃₃‐SPEEK75) shows a proton conductivity at 0.143 S cm⁻¹ under fully hydrated conditions at 80 °C and performs tensile strength about five times as much as did the sulfonated polyphosphazene membrane CF₃‐PS₁₁‐PSBOS₃₃. Further doping of sulfonated single‐walled carbon nanotubes (S‐SWCNTs) into the cross‐linked membranes on the screening of additives gives composite membrane CF₃‐PS₁₁‐PSBOS₃₃‐SPEEK75‐SWCNT possessing proton conductivity of 0.196 S cm⁻¹, even higher than that of Nafion 117 and a tensile strength comparable to that of Nafion 117. However, this significance of the composite membrane in the proton conduction is not observed in the test with a H₂/air fuel cell when it shows a maximal power density of 280 mW cm⁻² at 80 °C, whereas 294 mW cm⁻² is observed for CF₃‐PS₁₁‐PSBOS₃₃‐SPEEK75.