Polyethers block copolymers

Block copolymers such as styrene-butadiene-styrene (SBS) and its hydrogenated versions (SEBS), along with polyester-polyether block copolymers, can also be used to improve PBT impact. The SEBS and SBS copolymers [47], and especially their functionalized, grafted derivatives [48], show surprisingly good affinity for the polyester. 

Polyelectrolytes Polyether block copolymers Polyvinylamides dimethlyaminoethyl methacrylate For example, poly(7V-methyl-TV-vinyl acetamide) CSM (Sloan, 1995a,b) CSM (Sloan, 1995a,b) CSM (Sloan, 1995a,b) ... 

Membranes comprising silicone rubber coated onto polyimides, polyacrylonitrile or other microporous supports membranes are widely used [12,27]. Other rubbers such as ethylene-propylene terpolymers have been reported to have good properties also [28]. Polyamide-polyether block copolymers have also been used for pervaporation of some polar VOCs [29,30]... 

Polyamide-polyether block copolymers (Pebax , Elf Atochem, Inc., Philadelphia, PA) have been used successfully with polar organics such as phenol and aniline [32-34], The separation factors obtained with these organics are greater than 100, far higher than the separation factors obtained with silicone rubber. The improved selectivity reflects the greater sorption selectivity obtained with the polar organic in the relatively polar polyamide-polyether membrane. On the other hand, toluene separation factors obtained with polyamide-polyether membranes are below those measured with silicone rubber. 

Newer developments are polyester/polyether block copolymers (Hytrel, Amitel), etc. By choosing various levels of block length ratio, a broad spectrum of stiffnesses (or hardnesses) can be obtained, which practically fills the gap between rubbers and thermoplasts. TPE s form a rapidly growing class of materials, which find an increasing number of applications. 

Tsubouchi and Yoshikawa [79] are concerned with pervaporation separation of benzene/cyclohexane mixtures using membranes based on polyamide/polyether block copolymers. It has been established that the separation factor increases with the increase in the polyamide component containing polar amide groups capable of forming hydrogen bonds e.g., the 1 1 block copolymer of polyamide 12 and polyoxyethylene has the benzene/cyclohexane separation factor /3p = 2.8 and the flux 2 = 300 g/m h a more rigid 3 1 polyamide 12/polyoxyethylene block copolymer has a much higher separation factor )8p = 5.0 and 2 = 80 g/m h. 

Tsubouchi K and Yoshikawa M. Pervaporation separation of benzene/cyclohexane mixtures through polyamide-polyether block copolymer membranes. Membrane (Maku) 1998 23(6) 322-326. 

Water (1) + Pluronic P105 (2). Pluronic PI05 is a polyether block copolymer (EO37PO58EO37, where EO and PO denote ethylene oxide and propylene oxide segments, respectively). At elevated temperatures (above 40—60 °C), this block copolymer self-assembles in water and in water + cosolvent as micelles. At low temperatures and concentrations, the block copolymer molecules are present in solution as independent polymer chains. We carried out the calculation at the low ... 

Wong, E.W. Urethane-Polyether Block Copolymer Membranes for Reverse Osmosis, Ultrafiltration and Other Membrane Processes, ORF Record of Invention No. 335, 1969. 

NNMR spectra of polyamide/polyether block copolymers based on polyethylene oxide) and either nylon-6 or nylon-12 are dominated by peaks at approximately 119 ppm, arising from the amorphous nylon phase. In addition, both polymers also exhibit a shoulder. Downfield (about 112 ppm) and upheld (about 117 ppm) shoulders indicate that polyamide phases exist as a (nylon-6) and y (nylon-12) forms, respectively (62). 

To prepare the graft copolymer, a PO (MW = 50 to 1,000 kg/mol) was either dissolved or swollen in an inert hydrocarbon, monomers (>80 wt% of a methacrylic ester, CH2=C(CH3)COOR) and an initiator was added to the heated mixture while stirring. As a result, acrylic branches of a relatively high molecular weight (MW = 20 to 200 kg/mol) were grafted onto the PO macromolecules. The graft copolymer could be used as a compatibilizer-cwm-impact modifier in a variety of polymers selected from between PO, acrylic polymers, SAN, EVAc, PA, PEST, PC, POM, PAr, PVC, ABS, PVDC, cellulosics, polyester-polyether block copolymers, PEA, PEEK, PEI, PES, CPVC, PVDF, PPE, PPS, PSF, TPU, PAI, PCL, polyglutarimide, blends of PEST with PC or PVC [Ilendra et al., 1992, 1993]. 

PBT with segmented polyester-polyether block copolymer The miscibility was found to depend on the copolymer composition Gallagher et al., 1993... 

The wide applicability of aluminum porphyrin initiators (1) leads to a variety of tailored block copolymers such as polymethacrylate-polyether and polymethacrylate-polye-ster, as well as polymethacrylate-polymethacrylate and polymethacrylate-polyacrylate, that can be synthesized by sequential living polymerization of the corresponding monomers.- For example, when 1,2-epoxypropane (11, R = Me) is added to a polymerization mixture of methyl methacrylate (21, R = Me) with la at 100% conversion of 21, the polymerization of 11 takes place from the enolate growing end (32 ) to give a narrow MWD polymethacrylate-polyether block copolymer having an alcoholate growing terminal (Table 4). Likewise, the aluminum enolate species (32 ) can also react with lactones (14,15), thereby allowing the formation of a poly(methyl methacrylate)-polyester block copolymer with narrow MWD. 

Polyamide-polyether block copolymers can be formed by a variety of techniques. One of them consists of initial preparation of amine-terminated polyethers. This can be done by reacting hydroxv-terminated polyethers with acrylonitrile and then reducing the nitrile groups to amines ... 

Extensively studied nonionic surfactants are PDMS / polyether block copolymers [31] and poly(ethylene oxide) substituted trisiloxanes [32-35]. They are able to achieve a maximum surface tension depression to about 21 mN/m and a low critical micelle concentration (CMC) [36], These siloxane surfactants can self-assemble into a variety of... 

N. P. Patel, R. J. Spontak, Mesoblends of polyether block copolymers with Poly(ethylene glycol), Macromolecules, 37, 1394—1402 (2004). 

There are two generic types of permanent antistats hydrophilic polymers and inherently conductive polymers. Hydrophilic polymers are currently the dominant permanent antistats in the market. Typical materials that have been used successfully are such polyether block copolymers as PEBAX from Atochem. Typical use levels for these materials are in excess of 10%. B.F. Goodrich is supplying compounds utilizing their permanent antistat additive, STAT-RITE. Office automation equipment, such as fax and copier parts, is the principal application for permanent antistats based on hydrophilic polymers. The most common resins are ABS and high-impact polystyrene (HIPS). 

Silicones are polymers with backbones consisting of—[Si(R>2—O]— repeating units. They are prepared by reacting chlorosilanes with water to form silanols that condense to form siloxanes. Silicone oils made from dimethyldichlorosilane and methyltrichlorosilane are used as additives to reduce surface tension. Chemically modified silicone fluids, such as polysiloxane/polyether block copolymers, with broader ranges of compatibility have been described (175). 

Crystallizable Block Copolymer Morphologies While the largest part of the block copolymer literature describes totally amorphous materials, one or more of the blocks may form semicrystalline regions. Examples include polyester-polyether block copolymers (39), where the poly(tetramethylene terephthalate) polyester blocks crystallize, and the thermoplastic polyurethane elastomers, where the polyurethane hard blocks crystallize (40). 

Chen, D., et al. Morphology and biodegradation of microspheres of polyester-polyether block copolymer based on polycaprolactone/polylactide/ polyfethylene oxide). Polymer International, 49(3) p. 269. 2000. 

By anionic procedures, Teyssie and his coworkers prepared block copolymers of types AB, ABA, and BAB from tert-hniyl methacrylate and ethylene oxide. The initiators studied were (PhCHPh)K and K(naphthalene). Upon hydrolysis, polyacid-polyether block copolymers were formed [28]. 

J. L. Illinger, N. S. Schneider and F. E. Karasz, "Low Temperature Dynamic Mechanical Properties of Polyurethane-Polyether Block Copolymers", Poly. Eng. Sci. 1, 25 (1972). 

Okano, X., Uruno, M., Sugiyama, N., Shimada, M., Shinohara, I., Kataoka, K., Sakurai, Y. Suppression of platelet activity on microdomain surfaces of 2-hydroxyethyl methacrylate-polyether block copolymers. J. Biomed. Mater. Res. 20(7), 1035-1047 (1986)... 

Castaldo L, Maglio G and Palumbo R (1978) Synthesis of polyamide-polyether block copolymers, J Polym Sci Polym Lett Ed 16 643-645. 

Hashimoto H, Wakumoto H, Nagai K and Todo A (1986) Manufacture of polyamide-polyester-polyether block copolymers, JP Patent 62 246,930, to Mitsui Petrochemical Ind., Chem A6sfr 109 55457. 

Chem. Descrip. Silicone polyether block copolymer Uses Emulsiferfor highly stable water-in-silicone and org. oil systems in clear shampoos, skin care, hair care, antiperspirants and deodorants, color cosmetics pigment dispersant for mica and zinc oxide Features Formulation flexibility with a broad range of silicone and organic oil phases tolerates high level of antiperspirants salt can be used in cold or hot processes... 

Chem. Descrip. Polysiloxane-polyether block copolymer Uses Foam stabilizer and emulsifier for rigid PU and polyisocyanurate foams with max. demand on flow properties esp. for refrigeration and pipe insulation Properties Cl, vise, liq, sol. in common rigid foam polyols and resin preblends dens. 1,055 0,01 g/cc vise. 750 170 mPa-s solid, pt. < -8 C hyd. no. 100 10 cloud pt. 70 3 C (4% aq.) pH 6.5 1.5 (4% aq.)... 

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