Urethane-modified poly

A research program to have benzylic ether-type resin react with polyisocyanate for producing polyurethane or urethane-modified poly-isocyanurate foam is being promoted. A foam which has intermediate properties between phenolic foam and polyurethane foam can be produced. 

Preparation of Microcellular Foams. The major polyols for microcellular elastomers include aliphatic polyester diols having a molecular weight of about 1,000 to 3,000, and poly-epsilon-caprolactones. Poly(oxytetramethylene) glycols (PTMEG) can also be used. The polyisocyanates to be used for microcellular elastomers are TDI-prepolymers and liquid MDI, i.e., carbodiimide-modified MDI or urethane-modified MDI. Low-molecular-weight, active-hydrogen compounds such as chain extenders (difunctional compounds) and... 

The subject of surfactant-modified, water-soluble polymers, briefly discussed in Water-Soluble Polymers, is addressed in the last three sections (Chapters 16-28) of this book. These associative thickeners are covered in detail, ranging from the maleic acid copolymers of variable compositions introduced in various commercial markets in the early 1960s to the most recent entries (that is, in the open literature), hydrophobe-modified poly (acrylamide). Chapter 23 is complementary to the spectroscopic studies in Chapters 13-15 it explores new approaches to understanding associations in aqueous media. The three hydrophobe-modified polymers that have gained commercial acceptance in the 1980s, (hydroxyethyl)cellulose, eth-oxylate urethanes, and alkali-swellable emulsions, are discussed in detail. In particular, hydrophobe-modified (hydroxyethyl)cellulose, which is... 

E. Brinlmian, A. Foot, L. Van der Does, and A. Bantjes. Platelet deposition on copolyether urethane modified with poly(ethylene oxide). Biomaterials 11 200-205 (1990). 

Modification by the incorporation of metals or metalloids, styrene, vinyl acetate, poly(styrene-co-maleic anhydride), urethane linkages, and so on result in poly(ester amide) resins with good chemical properties and excellent thermal resistance. Some can also be used as effective antibacterial and biologically safe corrosion protective coating materials. Urethane-modified ethylenediamine tetraacetic add the fatty amide diol of linseed oil-based poly(ester amide) resin exhibits excellent physicomechanical properties, high thermostability up to 200°C and anticorrosive properties. ... 

Eventually, bis(2-hydroxyethyl)isosorbide may be chemically modified to form, bisacrylate esters or bis vinyl ethers, which can be used in photochemical or thermal cured vinyl resin compositions. Alternatively, this compound may be reacted with epichlorohy-drin and bases to form bis(glycidyl ether) adducts which may be used in epoxy resins. Bis(2-hydroxyethyl)isosorbide will find use as a monomer in many polymeric compositions, such as polyesters, poly(urethane)s, poly(ether sulfone)s. 

Some spacer molecules and the corresponding carrier polymers are shown in Table 3. Benzoquinone was bound to the surface of a polyfcarbonate urethane) modified with poly(4-hydroxybutyl acrylate) (PCU/HBA) and to the vinyl acetate grafted and saponified poly(ether urethane) (Mitrathane) (PEU/VA-plas-ma) [136-139],... 

De Nardo L, Fare S, Di Matteo V, Cipolla E, Saino E, Visai L, et al. New heparinizable modified poly(carbonate urethane) snrfaces diminishing bacterial colonization. J Mater Sci Mater Med 2007 18 2109-15. http //dx.doi.org/10.1007/sl0856-007-3083-9. ISSN 0957-4530. 

Figure 7. Adhesion of 5. epidermidis KH 11 onto polyether-urethane modified in a glow discharge treatment with different gases and acrylic acid (smaller columns adhesion after precoating of the polymer surfaces with a synthetic protein solution) where water = water contact angle of the modified poly-etherurethanes-...

Ahn T O, Choi I S, Lee S W and Jeong H M (1994) Thermal and mechanical properties of poly(ether urethane) modified by copolyamide segments, Macromol Chem Phys 195 2559-2567. 

HydrophobicaHy Modified, Ethoxylated Urethane. HEUR associative thickeners are in effect poly(oxyethylene) polymers that contain terminal hydrophobe units (66). They can be synthesized via esterification with monoacids, tosylation reactions, or direct reaction with monoisocyanates. There are problems associated with aH of the methods of synthesis. The general commercial procedure for their synthesis is by a step-growth addition of... 

Ionic polymers are also formulated from TDI and MDI (43). Poly(urethane urea) and polyurea ionomers are obtained from divalent metal salts of /)-aminohen2oic acid, MPA, dialkylene glycol, and 2,4-TDI (44). In the case of polyureas, the glycol extender is omitted. If TDI is used in coatings apphcations, it is usually converted to a derivative to lower the vapor pressure. A typical TDI prepolymer is the adduct of TDI with trimethyl olpropane (Desmodur L). Carbodiimide-modified MDI offers advantages in polyester-based systems because of improved hydrolytic stabihty (45). Moisture cure systems based on aromatic isocyanates are also available. 

The variation of mechanical parameters correlates with variation of AH sudden drop of tensile and impact strength with a thin modifier layer, then increase of strength with increase of poly(urethane urea) film — a minor increase of strength but a tangible one for specific impact strength. 

Careful XPS analysis of a series of poly(dimethylsiloxane-urea-urethane) multiblock copolymers demonstrated that, as well as a surface layer of siloxane, there was a layer enriched in the hard block immediately beneath this. The thickness of both these layers depended on the molecular weights of the soft and hard block segments, respectively112. Annealing of these copolymers increased the thickness of both layers. The same authors have also shown that the thickness of these layers of hard and soft blocks could be modified by use of solvent mixtures which selectively precipitate the polar hard block during film formation by solvent casting113. 

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