Well-defined multi-stimuli responsive fluorinated graft poly(ether amine)s (fgPEAs)

Well-defined multi-stimuli responsive fluorinated graft poly(ether amine)s (fgPEAs) were synthesized through nucleophilic substitution/ring-opening reaction of commercial poly(propylene glycol) diglycidyl ether and Jeffamine L100, followed by functionalization of hydroxyl groups in backbone by fluorinated alkyl carboxylic acid. fgPEAs are comprised of hydrophilic short poly(ethylene oxide) (PEO) and hydrophobic fluorinated alkyl chains, which are grafted on poly(propylene oxide) (PPO) backbone alternately to form well-defined structure. In aqueous solution, fgPEA11 and fgPEA12 self-assembled into multi-dispersed micelles, while fgPEA13 formed the uniform-sized micro-micelles with diameter of about 200 nm. These obtained micelles from fgPEAs were multi-responsive to temperature, pH and ionic strength with tunable cloud point (CP). It’s notable that CP of fgPEAs aqueous solution increased with the increasing amount of graft fluorinated alkyl chains.     

Absorption kinetics of carbon dioxide into aqueous ammonia solution: Addition of hydroxyl groups for suppression of vaporization

Aqueous ammonia can act as an alternative absorbent for CO₂ removal, but it has high volatility and reduces the ammonia concentration. We analyzed the hydroxyl additives 2-amino-2-methyl-1-propanol (AMP), ethylene glycol, and glycerol to reduce the vapor pressure of ammonia solutions. In addition, absorption efficiency groups of aqueous ammonia solutions containing hydroxyl additives were investigated. The results show that the addition of AMP, ethylene glycol, or glycerol to NH₃ reduced the vapor pressure of the absorbent by 14.0%, 22.7%, and 75.2%, respectively. The reaction rate constants of aqueous NH3 containing AMP, ethylene glycol, and glycerol additives at 293, 303, 313 and 323 K are given by $k_{2,NH_3 /AMP} = 4.565 \times 10^5 \exp ( - 1396.5/T)$ , $k_{2,NH_3 /ehylene glycol} = 1.499 \times 10^6 \exp ( - 1978.7/T)$ and $k_{2,NH_3 /glycerol} = 7.078 \times 10^6 \exp ( - 2413.3/T)$ , respectively.     

Preparation and characterization of amphiphilic block copolymer of polyacrylonitrile‐block‐poly(ethylene oxide)

The synthesis of polyacrylonitrile‐block‐poly(ethylene oxide) (PAN‐b‐PEO) diblock copolymers is conducted by sequential initiation and Ce(IV) redox polymerization using amino‐alcohol as the parent compound. In the first step, amino‐alcohol potassium with a protected amine group initiates the polymerization of ethylene oxide (EO) to yield poly(ethylene oxide) (PEO) with an amine end group (PEO‐NH₂), which is used to synthesize a PAN‐b‐PEO diblock copolymer with Ce(IV) that takes place in the redox initiation system. A PAN‐poly(ethylene glycol)‐PAN (PAN‐PEG‐PAN) triblock copolymer is prepared by the same redox system consisting of ceric ions and PEG in an aqueous medium. The structure of the copolymer is characterized in detail by GPC, IR, ¹H‐NMR, DSC, and X‐ray diffraction. The propagation of the PAN chain is dependent on the molecular weight and concentration of the PEO prepolymer. The crystallization of the PAN and PEO block is discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1753–1759, 2003     

Nonaqueous emulsion copolymerization of ethyl methacrylate/lauryl methacrylate in propylene glycol. I. Evaluation of stabilizing efficiency for PEO‐PS‐PEO triblock copolymers

Sixteen poly(ethylene oxide)–polystyrene–poly(ethylene oxide) (PEO‐PS‐PEO) triblock copolymers were synthesized by anionic polymerization. They were characterized by gel permeation chromatography and proton NMR. The molecular weight of these 16 PEO‐PS‐PEO triblock copolymers ranged from 5100 to 13,300. The polystyrene (PS) block length was between 13 and 41. The PEO block length was between 41 and 106. The polydispersity index for these PEO‐PS‐PEO triblock copolymers were 1.05 ± 0.02. When using these stabilizers in the emulsion copolymerization of ethyl methacrylate and lauryl methacylate in propylene glycol, only a narrow window of stability was observed. Stable latexes were formed only when the molecular weights of the PEO blocks were within the range of 5300–7700 and the molecular weights of the PS blocks were 2000–4000. The stabilizer ability for these triblock copolymers was correlated with their molecular weight and conformation in propylene glycol. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1951–1962, 2001     

Incorporation of nonionic emulsifiers inside styrene–methacrylic acid copolymer particles during emulsion copolymerization

Emulsion copolymerizations of styrene and methacrylic acid with polyoxyethylene nonylphenyl ether nonionic emulsifiers having various hydrophilic–lipophilic balance (HLB) values (13.7, Emulgen 911; 15.5, Emulgen 920; 17.2, Emulgen 931) were performed. The incorporation behavior of the nonionic emulsifiers, comprising polydisperse poly(ethylene oxide) (PEO) chain lengths, inside the particles was investigated. At the completion of the polymerization, the incorporated percentage of the lowest HLB emulsifier was 61%, much higher than that of the highest HLB one (10%). In both polymerizations, the amounts of the incorporated emulsifiers increased with conversion, and shorter PEO chain (i.e., lower molecular weight) components were predominantly incorporated over longer PEO chain components.     

Polarity index of surface-active ethylene oxide adducts

The polarity indexes of surface-active ethylene oxide adducts with varying lipophilic parts and varying content of ethylene oxide have been studied. An interesting relationship has been found between the fraction of ether groups and polarity index, which gives a polarity index line for every type of ethylene oxide adduct. It permits the calculation of polarity indexes of all ethylene oxide adducts of known composition with known polarity index of the lipophilic part. It also gives valuable information for evaluating different lipophilic substances as raw materials for ethylene oxide adducts.     

Micellization of Some Bile Salts in Binary Aqueous Solvent Mixtures

The micellization behavior of bile salts—sodium cholate and sodium deoxycholate was studied in aqueous methanol, ethanol and ethylene glycol mixtures (10–20 % v/v) over a temperature range (300–320 K) by surface tension and conductivity methods. Critical micelle concentration, extent of counter ion binding (α), interfacial property (A _min, ζ_max, π-CMC, $ \Updelta G_{\text{ad}}^{ \circ } $ ) and thermodynamic parameters ( $ \Updelta G_{\text{m}}^{ \circ } $ , $ \Updelta H_{\text{m}}^{ \circ } $ , $ \Updelta S_{\text{m}}^{ \circ } $ ) for the micellization process are reported and discussed.     

Aqueous reactive polyurethane prepolymer with poly(ethylene oxide) monomethyl ether side chains for the hydrophilic finishing of poly(ethylene terephthalate) fabrics

In this study, a series of aqueous polyurethane (PU) prepolymers were synthesized with 4,4‐methylene bis(isocyanatocyclohexane), poly(ethylene glycol) or polycaprolactone diol (PCL), methyl ethyl ketoxime, and dispersing centers produced by isophorone diisocyanate, N‐diethanol amine, and poly(ethylene oxide) monomethyl ether (PEO), containing different hydrophobic groups (? CH₃ and ? C₆H₄C₉H₁₉) at the end. The thermal properties of the prepolymers and the characteristics of poly(ethylene terephthalate) (PET)‐treated fabrics were investigated. The glass‐transition temperature was the highest in the CC prepolymer containing a benzene ring (? C₆H₄C₉H₁₉) and a long PEO side chain, and it was the lowest in the CA prepolymer having a longer PEO side chain. The CB prepolymer containing a shorter PEO side chain did not produce a melting point of PEO, although a heat endothermic peak of the PCL crystal appeared. The melting point and enthalpy from PEO of the CA prepolymer were larger than those of the CC prepolymer. With respect to the hydrophilic finishing effects of aqueous PU prepolymers for PET fabrics, the fabric treated with the CB prepolymer had higher add‐on and washing durability than the fabrics treated with the CA prepolymer, which was followed by the CC prepolymer with the lowest, but the opposite trend was found for the hydrophilic properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Polymerization of cyclohexene oxide by methyl-4-[bis(4-bromophenyl)amino]benzoate cation radical salts

Methyl-4-[bis(4-bromophenyl)amino]benzoate cation radical salts having non-nucleophilic anions such as $ {\text{SbF}}^{ - }_{6} $ , $ {\text{PF}}^{ - }_{6} $ and $ {\text{AsF}}^{ - }_{6} $ were newly prepared and found to be very active initiators for the polymerization of cyclohexene oxide at room temperature, in dichloromethane without any external stimulation. The effects of counter ion structure, salt and monomer concentration on the polymerization yield and molecular weight, and the mechanism of initiation are presented.     

Architecture of rod consisting of hyperbranched pendant chains‐coil block copolymers by ATRP approach

Atom transfer radical polymerization (ATRP) was applied to a novel synthesis of rod consisting of hyperbranched pendant chains‐coil block copolymers. The procedure included the following steps: (1) esterification reaction of poly(ethylene glycol) methyl ether (PEO) with 2‐bromoisobutyryl bromide (BIBB) yielded a PEO‐Br macroinitiator, (2) ATRP method of 2‐hydroxylethyl methacrylate (HEMA) using PEO‐Br provided PEO‐block‐poly(2‐hydroxyethyl methacrylate) (PHEMA) block copolymers, (3) esterification of PEO‐block‐PHEMA with BIBB yielded block‐type polyinitiator, and (4) ATRP of HEMA‐Br inimer using block‐type polyinitiator provided coil‐rod (consisting of hyperbranched pendant chains) block copolymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis of graft copolymer polyethylene‐ graft‐poly(ethylene oxide) by a new anionic graft‐from polymerization

A series of amphiphilic graft copolymers, PE‐graft‐PEO, containing hydrophobic polyethylene (PE) as the backbone and hydrophilic poly(ethylene oxide) (PEO) as the side‐chain, have been synthesized by a novel route. The graft structure and the molecular weight, as well as the molecular weight distribution of the graft copolymer can easily be controlled. The molecular weight of the side‐chain PEO is proportional to the reaction time and the monomer concentration, which indicates the ‘living’ character of the anionic polymerization of ethylene oxide. The produced copolymers PE‐graft‐PEO were characterized by ¹H NMR and DSC measurements. Copyright © 2004 Society of Chemical Industry     

Synthesis of end-branched poly(ethylene glycol)s by aqueous atom transfer radical polymerization

Summary This article reports the synthesis of novel hydrophilic end-branched poly(ethylene glycol)s, in aqueous media by atom transfer radical polymerization (ATRP). Poly(ethylene glycol)s with molecular weights 10,000 and 16,000 were end-functionalized and used as bifunctional initiators for the polymerization of a poly(ethylene glycol) macromonomer with a molecular weight of 2,000 (PEGMA), either by aqueous ATRP or in a watedmethanol (l/l V/V) mixture. For both macroinitiators a DP of 10 was the target, giving an average of 5 branches in each end. The rates of polymerization were of the same order of magnitude when the polymerizations were initiated by either of the two macroinitiators in watedmethanol (l/l V/V). When a bifunctional oligo(ethy1ene glycol) initiator (M_n = 600) was used to study the polymerization of PEGMA in water/methanol a reduction in the rate of polymerization was observed indicating an influence of the molecular weight of the initiator on the rate of polymerization. Received 25 Maich 2002/Revised 8 November 2002/Accepted 8 November 2002 Correspondence to Jorgen Kops     

Aggregation phenomena of amphiphilic UVB absorptive oligoesters containing p‐alkoxycinnamate and poly(ethylene oxide) blocks

The synthesis of new amphiphilic oligoesters containing a hydrophobic block based on p‐alkoxycinnamate and hydrophilic poly(ethylene oxide) is reported. Two hydrophobic monomers, 1,2‐(bis(4‐(2‐carboxyvinyl)phenoxy))ethane ( M2 ) and 1,12‐(bis(4‐(2‐carboxyvinyl) phenoxy))dodecane ( M12 ), were synthesized. Four oligoesters, poly((1,2‐(bis(4‐(2‐carboxyvinyl)phenoxy))ethane) ‐co‐(poly(ethylene oxide)200)) ( P2‐200 ), poly((1,2‐(bis(4‐(2‐carboxyvinyl)phenoxy))ethane)‐co‐(poly(ethylene oxide) 400)) ( P2‐400 ), poly((1,12‐(bis(4‐(2‐carboxyvinyl)phenoxy)) dodecane)‐co‐(poly(ethylene oxide)400)) ( P12‐400 ), and poly((1,12‐(bis(4‐(2‐carboxyvinyl)phenoxy))dodecane)‐co‐ (poly(ethylene oxide)1000)) ( P12‐1000 ) were then constructed by reacting the M2 or M12 with poly(ethylene oxide) (PEO) with lengths of ～ 4 (PEO 200), ～ 10 (PEO 400), or ～ 23 (PEO1000) units using multiple esterifications. These oligoesters possess UVB absorption properties and show good solubility in various organic solvents. Self‐assembly of the oligoesters into aqueous spherical colloids could be induced through an acetone to water solvent displacement technique. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

CBABC terpolymer-based nanostructured vesicles with tunable membrane permeability as potential hydrophilic drug nanocarriers

The self-assembly of an amphiphilic pentablock terpolymer, consisting of a pH-sensitive poly(2-vinylpyridine) (P2VP) central block, bearing at both ends hydrophilic poly(ethylene oxide) (PEO) end-capped with hydrophobic poly(ε-caprolactone) (PCL) blocks was investigated in aqueous media. When the polymer was transferred to aqueous medium through solvent exchange technique, micellar assemblies were obtained, with a morphological switch from “flower-like” crew-cut micelles to large compound vesicles upon partial quaternization of 2VP block. More importantly, well-defined polymer vesicles were formed when thin film hydration method was employed. Such polymersomes presented “flower-like” morphology, with a membrane composed of self-assembled P2VP hydrophobic central blocks shielded by PCL hydrophobic ends and surrounded by PEO looping chains at the inner and outer surfaces. The potential of the pentablock vesicles as drug delivery carriers was explored by encapsulation of calcein, a model hydrophilic drug, in the polymersomes and monitoring its release at different pH values simulating physiological environments. It is shown that the release profile of the nanoparticle formulations could be modulated by tuning the membrane permeability either through chemical (i.e. partial quaternization) and/or physical (i.e. pH variations) pathways.     

Synthesis and Characterization of Linear and Tri-Block PLLA–PEG–PLLA Blends

This study was conducted to synthesize poly(L-lactide)–poly(ethylene glycol)–poly(L-lactide) triblock copolymer (PEGLA) with different poly(L-lactide) block length, and explore its applicability in a blend with linear poly(L-lactide) (3051D NatureWorks) with the intention of improving heat seal and adhesion properties at extrusion coating on paperboard. Poly(L-lactide)–poly(ethylene glycol)–poly(L-lactide) was obtained by ring opening polymerization of L-lactide using poly(ethylene glycol) (molecular weight 6000 g mol^?1) as an initiator and stannous octoate as catalyst. The structures of the PEGLAs were characterized by proton nuclear magnetic resonance spectroscopy. The melt flow and thermal properties of all PEGLAs and their blends were evaluated using dynamic rheology and differential scanning calorimeter. All blends containing 10 wt% of PEGLAs displayed similar zero shear viscosities to neat poly(L-lactide), while blends containing 30 wt% of PEGLAs showed slightly higher zero shear viscosity. However, all blends displayed higher shear thinning and increased melt elasticity (based on tan δ). No major changes in thermal properties were distinguished from differential scanning calorimetric studies. High molecular weight PEGLAs could be used in extrusion coating with 3051D without problems.     

Surface modification of polypropylene by the entrapping method using the short‐chained stearyl‐alcohol poly(ethylene oxide) ether modifier

On the basis of the short‐chained modifier of stearyl‐alcohol poly(ethylene oxide) ether (AEO), an entrapping modification was carried out on the polypropylene (PP) surface for hydrophilic improvement. A swelling layer was confirmed locating in the amorphous region on the PP surface, from which the modifiers could penetrate into the surface. The AEO‐8 modifier achieved the optimal hydrophilic modification on the surface with a contact angle of 20.6° and modifier coverage of 19.2%. A microphase separation was speculated to occur between the poly(ethylene oxide) (PEO) chain of AEO and the PP substrate in the entrapping surface, after which surface‐enriched PEO chains could improve surface hydrophilicity, simultaneously, reserved stearyl chains in the surface could approach modifier fixation. Water immersion durability of the modified surface could be improved by establishing a covalent linkage in the surface‐fixed structure. This work gives more comprehensive insights in the entrapping modification on the semi‐crystalline PP surface based on the short‐chained and block modifier. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43607.     

Effect of Head Groups,Temperature, and Polymer Concentration on Surfactant—Polymer Interactions

The micellization behaviour of sodium dodecyl sulphate, sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, and cetylpyridinium chloride in water and in aqueous solutions of polyethylene oxide (PEO, molecular weight = 100,000) having concentrations (0.005–0.04 %, w/v) has been studied at different temperatures (288.15–318.15 K) using conductivity, surface tension, and viscosity methods. From conductivity measurements various micellar parameters, like critical micellar concentration (CMC), critical aggregation concentration (CAC), polymer saturation point (PSP), degree of ionization (β), and standard free energy of transfer ( \( \Delta G_{t}^{0} \) ), have been calculated. CAC values have been found to decrease with polymer concentration and increase with temperature. However, the PSP values increase with both polymer concentration and temperature for all surfactants. Similar parameters have also been calculated from surface tension data (CMC^σ, CAC^σ, PSP^σ) along with other parameters such as maximum surface excess concentration at the air/water interface ( \( \Gamma_{\hbox{max} } \) ), minimum area per molecule (A _min), and packing parameter (p). The CMC^σ, CAC^σ, and PSP^σ values are smaller than the corresponding CMC, CAC, and PSP values, but both show similar behaviour with temperature and concentration of polymer. Various parameters indicate that the presence of the aromatic ring in the head group of surfactant decreases its interaction with PEO, whereas the increased hydrophobicity in the tail leads to stronger interactions with PEO. Viscosity studies further supplement the conclusions drawn from the above results.     

Time-resolved gel permeation chromatographic study on poly(N-isopropylacrylamide)-block-poly(ethylene glycol) prepared by soap-free emulsion polymerization

To synthesize an amphiphilic block copolymer of poly(N-isopropylacrylamide)-block-poly(ethylene glycol) (NE), an aqueous soap-free emulsion polymerization system was employed where poly(N-isopropylacrylamide) (PNIPA), polymerized from the radically activated chain ends of poly(ethylene glycol) (PEG), forms micelle cores stabilized by PEG brush chains emanating there from. When this polymerization was carried out at temperatures equal to or higher than 34 °C, narrowly-dispersed NE, which cannot be obtained by solution polymerization, was successfully obtained. To elucidate the living nature of the soap-free emulsion polymerization, time-dependent monomer conversion and molecular weight of NE was investigated by time-resolved gel permeation chromatography (GPC). The results indicate that the compartmentalization of end radicals into micelles cores leads to the quasi-living behavior of the polymerization.     

Structural properties of poly(ether) macromonomer based hydrogels

Summary The major part of the present work discusses the synthesis and the properties of a series of hydrogels obtained by free radical copolymerization of α,ω-methacryloyloxy poly(ethylene oxide) (PEO) or poly(1,3-dioxolane) (PDXL) macromonomers. The influence of several parameters such as macromonomer molar mass, comonomer concentration, type of solvent, and crosslinking concentration on the weight degree of equilibrium swelling, the uniaxial compression modulus and the thermodynamic interaction parameter was investigated systematically. Hydrogels whose elastic chains are constituted of a short central PDXL block surrounded by two hydrophilic PEO blocks were prepared according to the same strategy. PDXL is known to be sensitive to acidic degradation due to the presence of acetal groups. Therefore, once placed in acidic media (in water or in an organic solvent) network degradation occurred. The solid-state properties of the different PEO or PDXL co-networks were examined by DSC, and compared to those of linear PEO or PDXL chains and to those of homopolymeric PEO or PDXL networks.     

Preparation and properties of poly(ethylene oxide) star polymers

Poly(ethylene oxide) (PEO) star polymers were prepared by anionic polymerization of methacryloyl chloride and glyceryl trimethacrylate with sec‐butyllithium in cyclohexane. The ensuing polymers were grafted with poly(ethylene glycol) of molecular weight 400. The final product was washed with methylene chloride and analyzed with infrared spectroscopy, differential scanning calorimetry, and thermogravimetry. Star polymers of PEO were also prepared by anionic polymerization of glycidol with sec‐butyllithium in cyclohexane. The initiator was chosen so as to yield a polymer of 10,000 molecular weight. The resulting polymers were analyzed by nuclear magnetic resonance, infrared spectroscopy, and thermogravimetry. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 322–327, 2003