High pressure phase behavior for the binary mixture of pentafluoropropyl methacrylate and poly(pentafluoropropyl methacrylate) in supercritical carbon dioxide and dimethyl ether

Pressure-composition isotherm is obtained for the carbon dioxide+2,2,3,3,3-pentafluoropropyl methacrylate (PFPMA) using static apparatus with a variable volume view cell at temperature range from 40 °C to 120 °C and pressure up to 130 bar. This system exhibits type-I phase behavior with a continuous mixture-critical curve. The experimental result for carbon dioxide+PFPMA mixture was modeled using the Peng-Robinson (P-R) and multi-fluid nonrandom lattice fluid (MF-NLF) equation of state. Experimental cloud-point data of pressure up 470 bar and temperature to 182 °C were reported for the binary mixture of poly(2,2,3,3,3-pentafluoropropyl methacrylate) [Poly(PFPMA)] in supercritical carbon dioxide and dimethyl ether (DME). The Poly(PFPMA)+carbon dioxide and Poly(PFPMA)+DME systems showed LCST behavior.     

Improvement of the physical properties of poly(methyl methacrylate) by copolymerization with pentafluorophenyl methacrylate

Copolymers of methyl methacrylate (MMA) and pentafluorophenyl methacrylate (PFPMA) of various compositions were prepared with a free‐radical initiator. When PFPMA was included in the copolymers, the glass‐transition temperatures increased and showed a positive deviation from the Gordon–Taylor equation. A copolymer containing 20 wt % PFPMA exhibited almost zero orientational birefringence, and the photoelastic birefringence became zero when the copolymer contained 13 wt % PFPMA. When 20 wt % PFPMA was incorporated into the MMA copolymer, its water absorption decreased to 0.4 wt % versus 1.8 wt % for poly(methyl methacrylate) (PMMA) under the same condition. The flammability of the PFPMA/MMA copolymer was reduced in comparison with that of the MMA homopolymer. The refractive indices of the PFPMA/MMA copolymers were very close to that of PMMA, and the transmittances of the copolymers were slightly better than that of PMMA. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Anionic polymerization of fluorine-containing vinyl monomers

Summary The anionic polymerization of pentafluorophenylmethyl methacrylate (PFPMA) were examined with several anionic initiators. The initiators of relatively low activity such as t-C₄H₉OK, organozinc compounds and Al(C₂H₅)₃ produced poly(PFPMA) in fairly high yields though no polymer was obtained by the initiations of n-C₄H₉Li and C₂H₅MgBr within 7 days. The anionic polymerization reactivity of PFPMA was found to be strongly affected by the pentafluorophenyl group though the e-value of PFPMA is similar to those of methyl methacrylate and benzyl methacrylate.Part 7, Polym. J. 19, 958 (1987)     

Spontaneous copolymerization of N-(2-hydroxyethyl)ethyleneimine with maleic anhydride

Summary The copolymerization of N-(2-hydroxyethyl)ethyleneimine, (HEEI) as nucleophilic monomer and maleic anhydride (MA) as electrophilic monomer in the absence of initiator in acetonitrile was investigated. Copolymers were characterized by IR, ¹H-NMR and ¹³C-NMR spectroscopy. The copolymer composition depends on the monomer ratio in the feed, determined by ¹H-NMR spectroscopy. The presence of MA bridges between copolymer chains was established by spectroscopic analysis. At lower temperature the yield and molecular weight of copolymers decrease as well as the MA unit content in the copolymer.     

Poly[N-(2-hydroxypropyl)methacrylamide]. IV. Heterogeneous polymerization

Kinetics of radical heterogeneous polymerization of N-(2-hydroxypropyl)methacrylamide was studied in acetone at 55°C. The values of reaction order with respect to the monomer (1.6) and to the initiator (0.5) indicate a bimolecular termination and degradative transfer during the chain growth. The over-all rate constant of polymerization was found to be 5.6.10-4. Addition of a small amount of a solvent (methanol) to the polymerization mixture led to an increased polymerization rate and increased molecular weight of the resulting polymer, but a higher amount of the solvent brought about a decrease of both characteristics. The Occurence of maxima on the dependences of R_p, as well as M?_w on the monomer concentration was interpreted in terms of the classical Bamford and Jenkins theory.     

Using dilatometry in the reversible addition fragmentation transfer polymerization of N-(S)-(−)-α-methylbenzyl methacryloylamine

Optically active polymers were prepared using reversible addition-fragmentation chain transfer polymerization (RAFT) of N-(S)-α-methylbenzylmethacryloylamine (N-(S)-α-MBMA), a functional optically active monomer. RAFT polymerizations were carried out at 70 °C in ethanol using AIBN as a thermal initiator and benzyl or (1-phenyl)ethyl dithiobenzoate (BDB and PEDB, respectively) as the RAFT agents. The kinetic study was performed by dilatometry. Plots of conversion vs time indicated that the polymerizations followed first order kinetics. ¹H NMR, IR, and UV–vis spectrophotometric studies confirmed the presence of thiocarbonylthio moieties (−SCS-) in the polymer chains. The molecular weight distributions (MWDs) were moderately narrow with polydispersity indices between 1.3 and 1.6, which indicated that the control of the reaction was not completely achievement using BDB or PEDB as RAFT agents. The optical activity [α]_D²⁵ measurements of synthesized polymers by RAFT did not show a noticeably linear increase dependence with respect to molecular weight, as was previously reported for another controlled free radical polymerization (CRP) system.     

离子液体中丙烯腈三元共聚的研究

采用离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)为溶剂,进行了丙烯腈(AN)、丙烯酸甲酯(MA)、衣康酸(ITA)的自由基三元共聚反应的研究。讨论了总单体浓度、引发剂含量、聚合时间、MA含量、ITA含量对共聚物相对分子质量和转化率的影响。结果表明:以离子液体[BMIM]BF4为溶剂,AN、MA和ITA可发生三元共聚,聚合物相对分子质量可达10万以上;且MA的含量可以很低直至为0,对聚合物相对分子质量影响不大;以离子液体为溶剂的共聚物的化学结构与以NaSCN水溶液为溶剂的聚合物的结构相似。     

Surface and mechanical properties of hydrophobic silica contained hybrid films of waterborne polyurethane and fluorinated polymethacrylate

The surface and mechanical properties of hybrid films of waterborne polyurethane (WPU) and fluorinated polymethacrylate (FPMA), and high-hydrophobic silica (SiO₂) contained hybrid films of FPMA/WPU were investigated. X-ray photoelectron spectroscopy confirmed that the surfaces of hybrid films exhibited notable fluorine enrichment. Scanning electron microscopy observation demonstrated that micro-scale rough structures consisted of sub-micro papillae and micro-scale wrinkles formed on the surfaces of FPMA/WPU. This was attributed to the enhanced phase separation of WPU and the incompatibility of low-surface-energy FPMA and WPU. Colloidal SiO₂ was modified by polydimethylsiloxane and the modified SiO₂ was reactive and high-hydrophobic. After the addition of reactive SiO₂, the rough structures became micro-scale striped wrinkles studded with nano- and sub-micro papillae formed by the high-hydrophobic SiO₂. The combination of the fluorine enrichment and the rough structures accounted for the high hydrophobic FPMA/WPU film and superhydrophobic SiO₂/FPMA/WPU film.     

Reversible addition-fragmentation chain transfer polymerization of 7-(4-(acryloyloxy)butoxy)coumarin

The light sensitive vinyl monomer with coumarin unit, 7-(4-(acryloyloxy)butoxy)coumarin (7AC), was synthesized. The reversible addition-fragmentation chain transfer (RAFT) polymerization of 7AC, initiated by 2,2′-azobisisobutyronitrile (AIBN), was carried out using 2-cyanoprop-2-yl dithiobenzoate (CPDB) as a RAFT agent in N,N-dimethylformamide (DMF) solution. The kinetics exhibited first-order relationship with respect to the monomer concentration. The molecular weight of the polymer increased linearly with the monomer conversion. The chain extension of poly(7-(4-(acryloyloxy)butoxy)coumarin) (P7AC) using styrene (St) as the second monomer demonstrated that the obtained polymers were almost “living”. The fluorescence intensity of P7AC increased with the molecular weight of P7AC and was stronger than that of the monomer. The obtained polymer had strong ultraviolet (UV) absorption at 322 nm. The molecular weights of the polymer had no effect on its ultraviolet absorption intensity. The coumarin structure existing in P7AC underwent [2 + 2] cycloaddition reaction (photodimerization) under UV irradiation in tetrahydrofuran (THF) solution, which can be further used to prepare small particles from the single polymer.     

超声辐射下氨基硅油的合成研究

以八甲基环四硅氧烷(D4)作为反应单体,六甲基二硅氧烷(MM)为封端剂,N-β-氨乙基-γ-氨丙基甲基二甲氧基硅烷(DL-602)为氨基硅烷偶联剂,二甲亚砜(DMSO)为促进剂,氢氧化钾为催化剂,采用本体聚合,分别在超声辐射和非超声辐射条件下,合成氨基硅油。讨论了超声功率、超声时间、促进剂、封端剂、反应温度及反应时间对产物的粘度、流体力学半径及其分布的影响。结果表明,采用超声辐射不仅能够增大产物粘度、缩小分子量的分布,还能提高催化剂的效率。当超声功率为140 W,超声时间80 min,反应温度90℃,反应时间7 h,KOH、DMSO、MM用量分别为D4单体用量的0.04%,0.5%,0.1%时,合成的氨基硅油粘度最大。     

FI Zr-type catalysts for ethylene polymerization

Two FI-type catalysts of Bis[N-(3,5-dicumylsalicylidene)-naphthylaminato]zirconium(IV) dichloride (catalyst (a)) and Bis[N-(3,5-dicumylsalicylidene)-anthracylaminato]zirconium(IV) dichloride (catalyst (b)) were prepared and used for ethylene polymerization comparatively. Methylaluminoxane (MAO) was used as cocatalyst. Polymerization reactions of ethylene using the prepared catalysts at the different conditions of polymerization were carried out. Plurality of the fused aromatic rings on the N atom of the imine in the catalyst structure affected the polymerization activity and molecular weight of the resulting polymer as well. Productivity of the prepared catalysts increased with the addition of [Al]/[Zr] molar ratio. The highest activity was observed at about 35–40 °C for the catalysts. The catalyst (b) produced higher viscosity average molecular weight (M_v) of the obtained polyethylene, while generally the activity of the catalyst (a) was higher than the catalyst (b). Similar behavior was observed for the polymerization carried out at the monomer pressure of 2 to 6 bars using the catalysts. The higher the pressure the more activity of the catalysts obtained, in the range studied. Crystallinity and melting point of the obtained polymer were between 55–65% and 120–135 °C respectively. Higher pressure increased both the crystallinity and the M_v values of the resulting polymer. The polymerization was carried out using different amounts of hydrogen. Higher amount of hydrogen could increase the activity of the catalysts. A linear dependence between the polymerization time and the molar weight was observed, however the polydispersity was broadened with the time.     

Synthesis of poly(N,N,N-trimethyl–N-2-methacryloxyethyl) ammonium chloride initiated by anodically generated Sn2+ cation

Cationic polymerization of N,N,N-trimethyl–N-2-methacryl oxyethyl ammonium chloride (DMAEM-MC) was studied using a new synthesis technique and new initiator system, Sn2+. The Sn2+ was produced by the electrolysis of a sacrificial anode. The polymer was prepared in a batch reactor using only Sn material as electrodes. Factors affecting the conversion and average molecular weight of the polymer by electrolysis were obtained. On the one hand, the results indicated that the agitation rate, initial pH, current density and assembly of electrodes significantly affected both conversion and polymer molecular weight. On the other hand, temperature and monomer concentration were minor factors in the electropolymerization, while these two factors were the major factors in conventional chemical methods. The optimal pHi and agitation rate were 5.50 and 0 rpm, respectively. The reaction rate increased with current density; however, the current efficiency decreased with increase in current density. The results also revealed that the optimum reaction temperature and monomer concentration were 25 C and 0.73 m, respectively.     

Rheology and microstructure of functionalized polymer‐modified asphalt

Viscoelastic and morphological properties of functionalized‐polymer‐modified asphalt, FPMA, have been described as function of number of epoxy groups presented in the functionalized polymer. At low temperatures, simple viscoelastic models can predict the elastic response of FPMA at short times and its viscous behavior at long times. The increase of epoxy groups yielded an increase on activation energy for viscous deformation of FPMA, and so, on its resistance to irreversible deformations under strain cycles. From ambient to higher temperatures, emulsion model can predict rheological properties of FPMA because they behave as viscoelastic emulsions. Modification of relaxation spectrum for FPMA due to the presence of a polymer network was not as strong as in normal PMA, thus, the rheological behavior of FPMA was found similar to systems having weak networks. However, the network became stronger as the number of epoxy groups was increased. This trend was verified by morphology of FPMA. Emulsion‐like structure was observed for all FPMA but differentiating each other by the polymer particle size. It was also observed that increase on epoxy groups, polymer particle size in the FPMA decreased, and higher stability at 180°C of FPMA was observed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Polymerization of styrene using N-(p-tolyl)-N′,N′-diethyldithiocarbamoylacetamide as photoiniferter

N-(p-Tolyl)-N′,N′-diethyldithiocarbamoylacetamide was prepared and used as a new photoiniferter for polymerization of styrene in bulk under UV light. This photopolymerization showed some specific character, i.e., molecular weights of resulting polymers increase with reaction time and monomer conversion, respectively. The reversible reaction between growing radical and dormant species was confirmed by electron spin resonance using 2-methyl-2-nitrosopropane as a spin trapping agent. Thus, the end functionalized polymer, N,N-diethyldithiocarbamoyl-terminated polystyrene, reinitiated photopolymerization of methyl methacrylate and vinyl acetate to form block copolymers. The molecular weight distribution about 2.7 indicated that the polymerization is not a strictly living radical polymerization. © 1996 John Wiley & Sons, Inc.     

Hyperbranched poly(arylene ether phosphine oxide)s

Summary New AB₂ and A₂B monomers, bis(4-fluorophenyl)-4'-hydroxyphenylphosphine oxide and bis(4-hydroxyphenyl)-4'-fluorophenyl-phosphine oxide were prepared and converted to corresponding hyperbranched poly(arylene ether phosphineoxide)s with hydroxyphenyl and fluorophenyl end functional groups. While the dihydroxy monomer gave a low molecular weight polymer, the difluoro monomer produced a high molecular weight hyperbranched polymer. The glass transition temperature of the obtained polymers was 266°C and 230°C, and 5% weight loss temperature was 491 °C and 391 °C, respectively. The fluorophenyl-terminated hyperbranched polymer was soluble in CHCl₃, but the hydroxyphenyl-terminated polymer was not soluble in CHCl3 even though it has lower molecular weight than the fluorophenyl-terminated polymer, indicating that properties of the hyperbranched polymers markedly depend on end functional groups as well as their molecular weight. Received: 23 August 2000/Revised version: 19 October 2000/Accepted: 31 October 2000     

Optical and thermal properties of methyl methacrylate and pentafluorophenyl methacrylate copolymer: Design of copolymers for low-loss optical fibers for gigabit in-home communications

As a novel base material for low-loss graded index plastic optical fibers (GI POFs) in gigabit home networks, a copolymer of methyl methacrylate (MMA) and pentafluorophenyl methacrylate (PFPMA) was prepared and its thermal and optical properties were investigated. When the PFPMA content in the monomer feed was 0-50 mol%, both the glass transition temperature (T_g) and the decomposition temperature of the copolymer were higher than that for PMMA, which is the base material for many commercially available POFs. The transmittance of the copolymer was also found to be higher than that of PMMA since it has fewer C-H bonds per unit volume. As the core material of GI POFs, MMA-co-PFPMA (65/35 mol%), which had the highest T_g of 118 °C was utilized. A low-loss GI POF with an attenuation of 172-185 dB/km at the emission wavelengths of a high-speed light source (670-680 nm) was successfully obtained for the first time.     

酶促木质素与酚聚合反应分子量及分布实验

在反相微乳液系统中 ,进行了过氧化物酶催化木质素与酚共聚反应实验 ,考察了酶浓度、WO(水 /表面活性剂 ,质量比 )、表面活性剂浓度、单体 (酚、木质素 )浓度及醇烃比对聚合物分子量的影响。结果表明 ,聚合物重均分子量可用表面活性剂浓度、酶浓度、单体浓度及油相中醇烃比来调控。用单纯形优化法关联了实验数据 ,得到了聚合物重均分子量的关联式 :M =6 2 7× 10 4 (Y1× 10 7) -0 .3 4Y0 .982 Y0 .83 Y2 .4 64 Y1.0 55。聚合物分子量分布出现双峰 ,是两种反应机理竞争的结果。     

Preparation of new polymer from podophyllotoxin derivative

Summary The new monomer, 4α-acrylpodophyllotoxin(APPT) was synthesized from reaction of acryloyl chloride with the 4α-hydroxy of podophyllotoxin. The homo- and copolymer of new monomer with NIPAAm/AAm have been prepared by free radical polymerization. The new monomer and polymers have been characterized by IR, ¹H- and ¹³C-NMR spectra. The homopolymer have low the molecular weight but it is not oligomer, and the molecular weight of copolymer increased with decreasing new monomer content. The composition of copolymers was close to the original monomer composition. The distinction of antitumor activity among podophyllotoxin, new monomer and homopolymer was smaller. The copolymer with NIPAAm (The PAPPT content (mol-%) =43.7%) did not exhibit any antitumor activity at present condition of experimentation. Received: 30 July 2001/ Revised version: 3 September 2001/ Accepted: 14 September 2001     

Synthesis and Polymerization of N-(2,4,5-trichlorophenyl) Acrylamide Monomer and its Thermal and Antimicrobial Properties

N-(2,4,5-trichlorophenyl) acrylamide (CPAM) new monomer was synthesized by condensing acrylic acid and 2, 4, 5-tri chloro aniline using dicyclohexyl carbodiimide as a coupling agent. The CPAM monomer was characterized by ¹HNMR, FT-IR, and mass spectroscopy. Further, the CPAM monomer was homopolymerized by solution technique in toluene using azobisisobutyronitrile (AIBN) as an initiator. The CPAM monomer and its homopolymer were employed to screen an antimicrobial activity against E. coli, S. aureus, M. luteus, and B. subtilis microorganisms, which are representative of Gram-positive and Gram-negative bacteria using ciprofloxacin and Sulphametoxazol as standards. The results showed that the CPAM monomer has good antimicrobial activity, comparable with its homopolymer. Also, the CPAM homopolymer was investigated for its thermal stability by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).     

Low Temperature Initiation by 3-Mercaptopropionic Acid-Ce(IV) or -KMnO4 Redox System for Polymerization of Acrylamide Monomer

Polymerization of acrylamide monomer was performed at low temperatures using 3-mercaptopropionic acid-cerium(IV) sulfate and 3-mercaptopropionic acid-KMnO₄ redox systems in acid aqueous medium. Water soluble polyacrylamides containing 3-mercaptopropionic acid end groups were synthesized. The effects of mole ratio of acrylamide to initiator(n_MSA= n_Ce(IV)), polymerization time, temperature, and concentration of sulfuric acid on the yield and molecular weight of polymer were investigated. The decrease in the mole ratio of acrylamide/Ce(IV) at constant monomer concentration resulted in an increase in the yield but a decrease in molecular weight of polymer. The increase of reaction temperature from 20° to 70°C resulted in a decrease in the yield but indicated generally a constant value for the molecular weight of polymer. With increasing of polymerization time, the yield and molecular weight of polymer did not change mainly. Ce(IV) and Mn(VII) ions are reduced to Ce(III) and Mn(II) ions, respectively in the polymerization reaction. The existence of Ce(III) ion bonded to polymer was investigated by UV-visible spectrometry and fluorescence measurements. The amount of Mn(II) that is incorporated to the polymer was determined using graphite furnace atomic absorption spectrometry. The mechanism of this phenomenon is discussed.