• Title/Summary/Keyword: Phosphonium salts

Search Result 16, Processing Time 0.026 seconds

Thermally Induced Cationic Polymerization of Glycidyl Phenyl Ether Using Novel Xanthenyl Phosphonium Salts

  • Gupta, Mukesh Kumar;Singh, Raj Pal
    • Macromolecular Research
    • /
    • v.17 no.4
    • /
    • pp.221-226
    • /
    • 2009
  • The present study firstly describes the synthesis of novel, thermo-latent initiators based on xanthenyl phosphonium salts with different counter anions and phosphine moieties and secondly examines their efficiency in the bulk polymerization of glycidyl phenyl ether(GPE). The polymerization was performed with phosphonium salt initiators($I_{SbF6}$, $I_{PF6}$, $I_{AsF6}$ and $I_{BF4}$) at ambient temperature to $200^{\circ}C$ for 1 h. The order of initiator activity was $I_{SbF6}>I_{PF6}>I_{AsF6}>I_{BF4}$. To examine the effect of the phosphine moiety on the initiator activity, polymerization was carried out with $I_{SbF6}(Ph_{3}P)$ and $II_{SbF6}(Bu_{3}P)$ at ambient temperature to $170^{\circ}C$ for 1 h. The order of reactivity was $I_{SbF6}>II_{SbF6}$. In general, the conversion percentage increased with increasing polymerization temperature. The thermal stability of these salts was measured by thermo gravimetric analysis(TGA). The solubility of phosphonium salts in various organic solvents and epoxy monomers was also investigated.

Preparation and their humidity-sensitive properties of crosslinked polymer containing phosphonium salts (포스포늄염을 포함하는 가교 고분자의 제조 및 그들의 감습특성)

  • 이칠원;공명선;이승재
    • Proceedings of the KAIS Fall Conference
    • /
    • 2000.10a
    • /
    • pp.245-250
    • /
    • 2000
  • 고습도 또는 결로시 내수성을 지니는 저항형 습도센서를 제조하기 위하여 vinylbenzyl tributyl phosphonium chloride를 포함하는 4원 공중합체를 합성하여 저습도와 고습도 범위에서 측정이 가능한 습도센서용 감습막을 제작하였다. 1,5-dibrompentane과 4차 염화 가교 반응을 통하여 최종 저항형 습도센서를 제작하였다. 감습막은 알루미나 기판에 한 쌍의 금 paste가 인쇄된 전극을 사용하였으며, 감습막은 다양한 비율의 vinylbenzyl tributyl phosphonium chloride, 2-(dimethlamino)ethyl methacrylate, 2-ethylhexyl acrylate, 그리고 [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride 등을 이용하여 제조하였다. 감습막은 micro-syringe를 이용하여 도포하였으며 건조 oven에서 50℃에서 6시간 동안 가교반응을 진행하였다. 습도센서의 임피던스 특성은 2-(dimethylamino)ethyl methacrylate 또는 [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride의 함량이 증가할수록 감소하였다. vinylbenzyl tributyl phosphonium chloride / 2-(dimethylamino)ethyl methacrylate / 2-ethylhexyl acrylate / [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride의 조성비가 4/4/1/1인 공중합체의 경우 30-90%RH 범위에서 2.64 ㏁ - 3.11 ㏀의 임피던스 특성을 보였으며 우수한 직선성과 낮은 히스테리시스 나타내었다.

Humidity-Sensitive Characteristics and Reliabilities of Polymeric Humidity Sensor Containing Phosphonium Salts (포스포늄 염을 가진 고분자 습도센서의 감습 특성 및 신뢰성)

  • Kim, Ohyoung;Gong, Myoung-Seon
    • Applied Chemistry for Engineering
    • /
    • v.9 no.4
    • /
    • pp.554-560
    • /
    • 1998
  • Vinylbenzyl triphenyl phosphonium chloride(VTPC)/styrenes=3.7 copolymer was prepared for the moisture-absorptive polyelectrolyte dew sensor containing phosphonium salts. The humid membrane was fabricated on the gold/alumina electrode by dipping. The impedances were $11M{\Omega}$, $980k{\Omega}$, $50k{\Omega}$, and $11k{\Omega}$ at 70%RH, 80%RH, 90%RH and 95%RH, respectively, at $25^{\circ}C$ and the humidity-sensitive charactristic was suitable for the dew sensor. The temperature-dependent coefficient between $15^{\circ}C$ and $35^{\circ}C$ was found to be $-0.25%RH/^{\circ}C$ and the hysteresis falled in the ${\pm}2%RH$ range. The response time was found to be 45 sec for the relative humidity ranging from 70%RH to 98%RH at $25^{\circ}C$. The reliabilities such as temperature cycle, humidity cycle, high temperature and humidity resistance, electrical load stability, stability of long-term storage and water durability were measured and evaluated for the application as a dew sensor.

  • PDF

Synthesis and Properties of Epoxy-Clay Nanocomposites (에폭시-점토 나노복합체의 제조 및 성질)

  • 이충로;인교진;공명선
    • Polymer(Korea)
    • /
    • v.27 no.4
    • /
    • pp.392-395
    • /
    • 2003
  • Phosrhonium salt exchanged montmorillonites were prepared from a reaction between alkyl triphenyl phosponium bromide and Na$^{+}$-montmorillonite. Epoxy-clay nanocomposites were also prepared by using cycloaliphtic epoxy, methyl tetrahydrophthalic anhydride as a hardener, and triphenyl butyl phosphonium bromide as an accelerator. TEM and XRD results suggested that clay minerals in the epoxy-montmorillonites composite were intercalated. Mechanical properties such as tensile modulus and strength were measured and the effect of nanocomposite formation was also discussed.

Synthesis of 7-Arylidene Cephalosporanates for ${\beta}-lactamase$ Inhibitor (${\beta}-Lactamase$ 억제작용이 기대되는 7-Arylidene Cephalosporanate 유도체의 합성)

  • Lee, Jong-Min;Yim, Chul-Bu;Im, Chae-Uk
    • YAKHAK HOEJI
    • /
    • v.52 no.4
    • /
    • pp.311-315
    • /
    • 2008
  • The synthesis of 7-arylidene cephalosporanates for ${\beta}-lactamase$ inhibitor was described. The reactions of substituted benzyl halides $[1]{\sim}[3]$ with triphenylphosphine gave triphenylphcsphonium chlorides $[4]{\sim}[6]$. These phosphonium salts were treated with n-butyllithium to give ylides, which were reated with 7-oxocephalosporanate [7] by Wittig reaction to afford the 7-exomethylene cephalosporanates $[8]{\sim}[10]$. These cephalosporanates were oxidized to cephalosporanate sulfones $[11]{\sim}[13]$ with mCPBA. The deprotection of benzhydryl cephalosporanate $[8]{\sim}[13]$ with $AlCl_3$ and $NaHCO_{3}$ gave sodium salts of 7-arylidene cephalosporanates $[14]{\sim}[19]$.

Synthesis and ${\beta}-Lactamase$ Inhibitory Activity of 7-Exomethylene Cephalosporanates (7-엑소메칠렌 세팔로스포라네이트 유도체의 합성과 $\beta$- 락타메이즈 억제작용)

  • 이종민;최수항;이현수;임채욱;임철부
    • YAKHAK HOEJI
    • /
    • v.43 no.6
    • /
    • pp.782-788
    • /
    • 1999
  • 7-Oxocephalosporanate 1 was treated with phosphonium salts 2~4 by Wittig reaction to afford 7-exomethylene cephalosporanates 5~7. They were oxidized to sulfones 8~10 with mCPBA. Deprotecton of benzhydryl 7-exomethylene cephalosporanate with $AlCl_3$ and NaHCO_3$ gave sodium salts of 7-exomethylene cephalosporanates 11~16. The ${\beta}-lactamase$ inhibitory activity of synthesized compounds 11~16 were compared with sulbactam, tazobactam and clavulanic acid against Type I, II, III, IV and TEM-2 $\beta$-lactamase in vitro. Compound 15 showed more potent activity than sulbactam and clavulanic acid against Type III, IV ${\beta}-lactamase$ enzyme.

  • PDF

Characteristics of Electrode Potential and AC Impendance of Perchlorate Ion-Selective Electrodes Based on Quaternary Phosphonium Salts in PVC Membranes (제4급 인산염을 이용한 과염소산 이온선택성 PVC막 전극의 전극전위와 AC 임피던스 특성)

  • 안형환
    • Membrane Journal
    • /
    • v.9 no.4
    • /
    • pp.230-239
    • /
    • 1999
  • Perchlorate ion-selective electrodes in PVC membranes that respond linearly to concentration 106 M were developed by incorporating the quaternary phosphonium salts as a canier. The effects of the chemical structure, the contents of canier, the kind of plasticizer and the membrane thickness on electrode characteristics such as the electrode slope, the linear respone range and the detection limit were studied. With this results, the detectable pH range, selectivity coefficients and AC impedance characteristics were compared and investigated. The perchlorate ion substituents of the quaternary phosphonium salts like tetraoctylphosphonium perchlorate (TOPP) , tetraphenylphosphonium perchlorate(TPPP), and tetrabutylphosphonium perchlorate(TBPP) as a canier were used. The electrode characteristics were better in the ascending order of TBPP < TPPP < TOPP, with the increase of carbon chain length of the alkyl group. Dioctylsebacate(OOS) was best as a plasticizer, the canier contents were better with 11.76 wt% and the optimum membrane thickness was 0.19 mm. Under the above condition, the electrode slope was 56.58 mV/$^P{ClO}_4$,the linear response range was $10^{-1}$\times$10^{-6}$ M, the detection limit was 9.66 x $10^{-7}$ M. The performance of electrode was better than Orion electrode. The electrode potential was stable within the pH range from 3 to 11. The order of the selectivity coefficients for the perchlorate ion was sol < F < Br < 1. With the result of impedance spectrum, it was found that the equivalent circuit for the electrode could be expressed by a series combination of solution resistance, parallel circuit consisting of the double layer capacitance and bulk resistance and Warburg impedance. And solution resistance was almost not appeared and Warburg impedance was highly appeared by diffusion. Then Warburg coefficient was 1.32$\times$$10^74 $\Omega$ $\cdot$ ${cm}^2/s^{1/2}$.

  • PDF

An Efficient Synthesis of Phospha-Morita-Baylis-Hillman Adducts via Michaelis-Arbuzov Reaction of the DABCO Salt of Morita-Baylis-Hillman Bromide

  • Kim, Sung Hwan;Kim, Se Hee;Lee, Hyun Seung;Kim, Jae Nyoung
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.1
    • /
    • pp.133-138
    • /
    • 2013
  • An efficient synthesis of phospha-Morita-Baylis-Hillman adducts was carried out in good yields via the Michaelis-Arbuzov reaction of the DABCO salts of MBH bromides. Instead of a DABCO salt, a phosphonium salt could be effectively used for some substrates which showed some problems in the presence of DABCO.