Phenolformaldehyde resins

Acrylic Resins. The first synthetic polymer denture material, used throughout much of the 20th century, was based on the discovery of vulcanised mbber in 1839. Other polymers explored for denture and other dental uses have included ceUuloid, phenolformaldehyde resins, and vinyl chloride copolymers. Polystyrene, polycarbonates, polyurethanes, and acryHc resins have also been used for dental polymers. Because of the unique combination of properties, eg, aesthetics and ease of fabrication, acryHc resins based on methyl methacrylate and its polymer and/or copolymers have received the most attention since their introduction in 1937. However, deficiencies include excessive polymerization shrinkage and poor abrasion resistance. Polymers used in dental appHcation should have minimal dimensional changes during and subsequent to polymerization exceUent chemical, physical, and color stabiHty processabiHty and biocompatibiHty and the abiHty to blend with contiguous tissues. 

The Raymond ring-roll mill with its internal air separation is widely used to pulverize phenolformaldehyde resins. The usual fineness of grind is finer than 99 percent minus 200 mesh. Air at 4°C (40°F) is usually introduced into the mill to limit temperature rise. A typical 3036 Raymond mill using 34 kW (45 hp) will produce better than 900 kg/h (2000 Ib/h) at 99 percent minus 200 mesh. 

Using synthesized diallylsilazanes modification of the properties of some important industrial polymer composites based on phenolformaldehide resins has been carried out. Preliminary investigations showed that synthesized polymers in combination with phenolformaldehyde resins were successfully used as binding-components for polymer/graphite and polymer/carbon black electro-conducting composites. 

Besides the aforementioned, preliminary investigations showed that synthesized oligomers and polymers, in combination with phenolformaldehyde resin, were successfully used as binding component for polymer/graphite electro-conducting composites (ECC) [15, 16], Obtained ECC were recommended for creation of electrode material for electrolytic section and the chemical (fuel) sources of electrical energy (on the basis of analogous material) [16],... 

Schoenberg JB, Mitchell CA Airway disease caused by phenolic (phenolformaldehyde) resin exposure. Arch Environ Health 30 574-577, 1975... 

Novolac epoxy resins are produced by reaction of novolac, a phenolformaldehyde resin, with epichlorohyrin and a base. ... 

Some expl compns, contg C and examined at PicArsn included Illuminating Composition, Sr(N03)2 54, Mg 33, PVC 10, C 3 Ca stearate 1% Squib, NC, (lacquer) 51, KC103 44 C 555 Flare, Mg 44, NaCl04 35, Na202 4, phenolformaldehyde resin 15 graphite 255 ... 

Ordnance practices, the term combustible cartridge case is referred to cases fabricated from fibrous NC and a binder. Such cases produce no residue when fired in a conventional artillery weapon system. The term consumable cartridge case has been reserved for cases prepd from combustible materials other than NC, such as woodpulp or paper impregnated with a phenolformaldehyde resin In each type of case, fungicides, flash reducing agents and gun erosion inhibitors can be incorporated... 

Examples are the sulfonating of polyethylene film with chloro-sulfonic acid (60) the sulfonating of sheets of phenolformaldehyde resin (77) the treatment of a film consisting of polystyrene and polyvinylchloride with concentrated sulfuric acid (4) the sulfonating of films consisting of aliphatic vinylpolymers with chlorosulfonic acid (125) the sulfonating of copolymers of a monovinyl- and a polyvinyl compound (30). Also are used copolymers of aromatic monovinyl-compounds and linear aliphatic polyene hydrocarbons (3) copolymers of an unsaturated aromatic compound and an unsaturated aliphatic compound (76), and of reaction products of poly olefines and partially polymerized styrene (173). 

Process optimization of the thermal treatment of an ablation polymer material, based on phenolformaldehyde resins, was done by time and temperature, by the application of simplex optimization. 

Figure 28 Typical chronopotentiometric profile of a disordered carbon charged-discharged in Li salt-alkyl carbonate solution. The carbon was a Li doped polyacenic semiconductor (PAS) obtained by heat treatment of phenolformaldehyde resin [348]. Note the high capacity, the sloping potential profile and the hysteresis between the charge and discharge routes. (With copyrights from Elsevier Science Ltd., 1998.)...

Durez. Trademark of Hooker Chem Corp, for a line of phenolformaldehyde resins and molding compds, also including diallyl phthalate resins... 

Plastics Cyanoacrylate, epoxy resins, polyacrylates, phenolformaldehyde resins, polyurethane, rubber additives (thiuram, carbamates)... 

A typical commercial novolac epoxy resin (VI) produced by epoxidation of phenolic hydroxyl groups of novolac (see the section on phenolformaldehyde resins) by treatment with epichlorohydrin has an... 

Polymer chemistry is another field for application of the Sn methodology. It has recently been shown that phenolformaldehyde resins can be modified by reacting with 3-(pyridyl-2)-l,2,4-triazin-5-one. Incorporation of heterocyclic fragments in the structure of resins enabled to improve their selective sorption abilities toward Cu " and other ions of metals (Scheme 48) [157]. 

CHANGES IN CERTAIN PROPERTIES OF MODIFIED PHENOLFORMALDEHYDE RESIN NO. 236 AFTER HEAT TREATMENT AT TEMPERATURES UP TO 600 DEGREES. 

CHANGES IN CERTAIN PROPERTIES OF MODIFIED PHENOLFORMALDEHYDE RESIN NO. 236 AFTER HEAT TREATMENT AT TEMPERATURES UP TO 600 DEGREES. //ENGLISH TRANSLATION OF ZH. PRIKLAD. KHIM. 40 111 424-8,... 

DETERMINATION OF VOLUME CAPACITY OF SULFONIC PHENOLFORMALDEHYDE RESINS. 

If one compares the smoke-formation in combustion of 2-3 mm of samples from ABC-plastics, pol5winylchloride, polystyrene, polycarbonate, polytetrafluorethylene, phenolformaldehyde resin, polyestersulfone. 

Presently in cryogenics, composite polymer materials are widely used. These are glass and carbon plastics based on epoxy and phenolformaldehyde resins. But there are scanty data on their thermophysical properties, and they refer, as a rule, to positive temperatures. 

Plastics, such as acrylates and phenolformaldehyde resins (see also epoxy resins)... 

Malten KE, Seutter E (1984) Phenolformaldehyde resin in paper. Contact Dermatitis 11 127-128... 

An interesting method, used by A. Davis [213] to synthesize fragments of phenolformaldehyde resins, can be used to produce the products under consideration. By heating an alcoholic solution of a mixture of cyclohexanone with p-hydroxybenzaldehyde in the presence of sodium hydroxide, the authors produced the intermediate 2,6-bis-hydroxy-benzylidenecyclohexanone, which was converted to a dialkylenetriphenol after hydrogenation with heating with Pd/C ... 

Fig. 146. Stability to thermal decomposition of hardened epoxide (1) and phenolformaldehyde resins (2).

Figure 3.356. Dependence of wear of some plastic materials by temperature [959] I) plasticized PVC II) plasticized PMMA 111) pressing powder K-18-2 based on phenolformaldehyde resin IV) epoxy resin of high-thermal stability. Applied load 3, 9) 13 MPa 8, 12) 0.13 MPa 2, 11) 0.10 MPa 1, 10) 0.05 MPa 1) 0.05 MPa 6) 0.003 MPa 5) 0,015 4) 0006 MPa.

When the blends of polyesterimide-novolac and polyesterimide-resole are heated separately to 300 C or above and 200 C or above, respectively, it is found that the heated products are insoluble in solvents like N,N-dimethyl foimiamide (DMF), l methyl-pyrroli-done (NMP), 1,4-dioxane, m-cresol, etc. The insolubilil of the blends after heating is believed to be due to crosslinking. It is very likely that the phenolformaldehyde resin component of the polyblend provides the crosslinks. It has been observed that the blend containing as low as 10% P-F resin is capable of cross-linking. 

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