End-capped poly

Noell et al. reported the preparation of silica-poly(ether ether ketone) hybrid materials with improved physical properties.155 An amine-end-capped poly(ether ether ketone) was used to react with isocyanatopropyltriethoxysilane in tetrahydrofuran (THF). The triethylsilane-end-capped poly (ether ether ketone) was mixed with tetraethoxysilane (TEOS) in THF. Quantitative amounts of water were introduced into die system, and the mixture was reduxed at 80°C. The entire reaction mixture was allowed to further react in Tedon molds. Tough transparent materials were obtained by diis approach. 

The rate of hydrolysis of the partially ethoxylated polymer was retarded, although not to the extent calculated from theory (Fig. 25), suggesting some contribution to the rate of chain scission by an uncatalyzed process. End-capping poly (glycolic acid-co-lactic acid) has a similar effect on the rate of hydrolysis of this polyester (100). 

Although the biocompatibility and biodegradability of these materials were rapidly determined, the bioactivity of Si02-PCL hybrid materials was not studied until recently [99]. In order to provide bioactivity to Si02-PCL hybrid materials, Rhee prepared triethoxysilane end-capped poly(s-caprolactone) which was then cocondensed with tetraethyl orthosilicate and calcium nitrate via the sol-gel method. The Ca-containing PCL/silica hybrid so obtained showed in vitro bioactivity and biodegradability. The hybridization procedure between the a,co-hydroxyl PCL and silica phases was proposed to be as follows ... 

Fig. 10. Amide end-capped poly(hexafluoropropy-lene oxide) used for the inverse emulsion polymerization of acrylamide in C02 [123]...

This basic approach to chemical amplification was subsequently extended by Ito et al. [3] through resist formulations incorporating appropriately chosen triaryl sulfonium or diaryliodonium salt. For example, end-capped poly(phthalaldehyde) used in combination with an onium salt photoacid generator is an excellent self-... 

Goh HW, Goh SH, Xu GQ, Lee KY, Yang GY, Lee YW, Zhang WD (2003). Optical limiting properties of double-C60-end-capped poly(ethylene oxide), double-C -end-capped polyethylene oxide)/poly(ethylene oxide) blend, and double-C -end-capped poly(ethylene oxide)/multiwalled carbon nanotube composite. J. Phys. Chem. B 107 6056-6062. 

Hybrid materials have been made by incorporating end-capped poly(tetramethylene oxide) blocks to tetramethoxysilane sol-gel glasses. These materials have high extensibility with interdispersed organic and inorganic regions. 

Peng S, An Y, Chen C, Fei B, Zhuang Y, Dong L (2003) Thermal degradation kinetics of uncapped and end-capped poly(propylene carbonate). Polym Degrad Stab 80 141-147... 

Figure 7.8 Chemical structures of 2,6-bis(l methylbenzimidazolyl) pyridine (Mebip) end-capped poly(2,5-dioctyloxy-p-phenylene ethynylene) (PPE) (5) and poly(2,5-dioctyloxy-p-xylylene) (PPX 6) MSPs and pictures of the resulting fibers and films (Knapton, Iyer, et al. 2006 Knapton, Rowan, et al. 2006).

H. Cheradame, J. Habimana de la Croix, E. Rousset, and F.J. Chen, Synthesis of polymers containing pseudohalide groups by cationic polymerization. 9. Azido end-capped poly(2-methylpropene) by polymerization initiated by the system lewis acid-2-azido-2-phenylpropane, Macromolecules, 27(3) 631-637, January 1994. 

Fig. 16 TEM pictures showing nanoparticles of cholesteryl end-capped poly(NIPA-co-dimethylacrylamide). The nanoparticles were obtained by the dialyzing dimethylfor-mamide solutions of copolymers against water and subsequent freeze-drying. The initial concentrations of the copolymer in dimethylformamide were a-c 0.35 wt%, d 0.1 wt%, e, f 1.2 wt%. a, c-f were obtained for the copolymer with Mw = 3400 b was obtained for the copolymer with Mw = 8000. (Reprinted with permission from Ref. [55]. Copyright 2003 Elsevier)...

Table VII. Solvents for Acetate End-Capped Poly-n -Butyraldehyde...

Preparation of Coumarin Ester End-Capped Poly(E-Caprolactone-co-Trimethylene Carbonate)... 

M Poly(s-Caprolactone-co-Trimethylene Carbonate) (daltons) OH value (mol/g) M of Post UV Cured End-Capped Poly(E-Caprolactone-co-Trimethylene Carbonate) Coumarin Ester (daltons)... 

The specific inclusion of adamantyl groups in /3-cyclodextrin in aqueous environments has been used as binding interaction between adamantyl end-capped poly(ethylene oxide)263-264 or polyester and a cyclodextrin polymer. Even though the formation of linear chain extended structures was not specifically... 

Barentin C, Muller P, Joanny JF (1998) Polymer brushes formed by end-capped poly(ethylene oxide) (PEO) at the air-water interface. Macromolecules 31 2198-2211... 

Wong and coworkers. [82, 83] used solution and solid-state NMR to study the cure of the norbornene end-capped poly(imide)s 2NE/DDM and PMR-15. At lower cure temperatures, exo-endo isomerization was observed to be a major product [84]. Loss of cyclopentadiene was suggested to result in initiation of the partner maleimide, as well as Diels-Alder addition of cyclopentadiene with norbornene. There was no evidence of internal double bonds formed by incorporation of the cyclopentadiene into the polymer backbone. The solid-state spectra were very poorly resolved, but did allow confirmation of the mechanism of reaction [83]. Spectra obtained at higher fields did not show improved resolution, indicating that the dominant mechanism for line-broadening in these materials is the dispersion of isotropic chemical shifts resulting from frozen conformations. In later work, Milhourat-Hammadi and coworkers [84, 85] reported solution-state and NMR studies of PMR-15 prepolymers. 

S. Vuorinen, et al.. Sugar end-capped poly-d, 1-lactides as exdpienis in oral sustained release tablets. AAPS PharmSdTech 10 (2009) 566-573, doi 10.1208/sl2249-009-9247-9. 

Acrylamide was successfully polymerized in a supercritical inverse emulsion composed of an ethane-propane mixture as the continuous phase, water and acrylamide as the dispersed phase, and a mixed nonionic surfactant system as the emulsifier [86], AIBN [2,2 -azobis(isobutyronitrile)] was the initiator. The polymerization was subsequently repeated in supercritical CO2 [87]. The C02-philic surfactant used to produce the inverse emulsion was an amide, end-capped poly(hexafluoropropylene oxide). The process yielded polymers of average molecular weights from 5 x 10 to 7 x 10. ... 

Iliis paper descnbes a novel contact lens materim based on a methacrylate end capped poly (trifluoropropylmethylsiloxane)(TET), octafluoropentyl-methacrylate (OFPMA) and a wettmg agent 2-vinyl-4,4-dimethyl-2-oxazolin-5-one (VDMO). The trifluoropropylmethyl siloxane, fluorinated methacrylate methacrylate and VDMO in the correct concentration provide a lipid resistant, oxygen permeable, hydrophilic contact lens material. 

Synthesis of a DP 100 methacrylate end capped poly (65 mole % trifluoropropylmethylsiloxane)-co-(35 mole % dimethylsiloxane) (65-TFP) (Scheme 1)... 

BE Obeid, R., Tanaka, F., and Winnik, F.M., Heat-induced phase transition and erystallization of hydrophobically end-capped poly(2-isopropyl-2-oxazoline)s in v/aXer, Macromolecules, 42, 5818, 2009. 

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