Segment of novolak, illustrating the predominance of cresol subunits and presence of crosslinking.
Novolaks (sometimes: novolacs) are low molecular weight polymers derived from phenols and formaldehyde. They are related to Bakelite, which is more highly crosslinked. The term comes from Swedish "lack" for lacquer and Latin "novo" for new, since these materials were envisioned to replace natural lacquers such as copal resin.
Typically novolaks are prepared by the condensation of phenol or a mixture of p- and m-cresol with formaldehyde (as formalin). The reaction is acid catalyzed. Oxalic acid is often used because it can be subsequently removed by thermal decomposition. Novolaks have a degree of polymerization of approximately 20-40. The branching density, determined by the processing conditions, m- vs p-cresol ratio, as well as CH2O/cresol ratio is typically around 15%.[1]
Novolaks are especially important in microelectronics where they are used as photoresist materials.[2][3] They are also used as tackifiers in rubber.
^Ralph Dammel (1993). "Basic Chemistry of Novolaks". Diazonaphthoquinone-based Resists. Int. Soc. Optical Engineering. doi:10.1117/3.2265072.ch3. ISBN 9780819410191.
^Hinsberg, W. D.; Wallraff, G. M. (2005). "Lithographic Resists". Kirk-Othmer Encyclopedia of Chemical Technology. New York: John Wiley. doi:10.1002/0471238961.1209200808091419.a01.pub2. ISBN 9780471238966.
^Integrated Laboratory Systems (January 2006). Chemical Information Review Document for Diazonaphthoquinone Derivatives Used in Photoresists (PDF) (Report). National Toxicology Program.
Novolaks (sometimes: novolacs) are low molecular weight polymers derived from phenols and formaldehyde. They are related to Bakelite, which is more highly...
properties. Novolaks are produced by reacting phenol with methanal (formaldehyde). The reaction of epichlorohydrin and novolaks produces novolaks with glycidyl...
can further link generating tri- and tetra-and higher phenol oligomers. Novolaks (or novolacs) are phenol-formaldehyde resins with a formaldehyde to phenol...
Kerria lacca). He produced a soluble phenol-formaldehyde shellac called Novolak, but it was not a market success, even though it is still used to this...
Gil (2009). "Crosslinking and thermal stability of thermosets based on novolak and melamine". Journal of Applied Polymer Science. 114 (6): 4059–4065....
beetles). Baekeland produced a soluble phenol-formaldehyde shellac called "Novolak" but concluded that its properties were inferior. It never became a big...
(commonly Kovar) or ceramic. A common plastic used for this is epoxy-cresol-novolak (ECN). All three material types offer usable mechanical strength, moisture...
republic of Dagestan, populated by Chechens. Aukh encompasses parts of the Novolak, Khasavyurtovsky, Babayurtovsky and Kazbekovsky districts. The Chechens...
(DQ) 20-50% weight photosensitive hydrophobic, not water soluble Phenolic Novolak Resin (N) Frequently used for near-UV exposures Water soluble UV exposure...
support the leads and handling of the package. The plastic can be cresol-novolaks, siloxane polyimide, polyxylylene, silicones, polyepoxides and bisbenzocyclo-butene...
Municipal District • Municipal divisions 0 urban settlements, 12 rural settlements Time zone UTC+3 (MSK ) OKTMO ID 82639000 Website http://mo-novolak.ru/...
diazonaphthoquinone (DNQ), a chemical compound used for dissolution inhibition of novolak resin in photomask creation. They mathematically modeled effects, predicted...
polymers and resins from phenol-formaldehyde condensations (Bakelite, Novolak, and calixarenes). Similar crosslinking occurs in urea-formaldehyde resins...
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