Synthesis and properties of new novolacs based on heteroatom‐bridged phenol derivatives

Abstract

AbstractWe describe the synthesis and properties of new novolacs prepared by addition‐condensation of heteroatom‐bridged phenol derivatives and formaldehyde. The trifluoroacetic acid‐catalyzed polymerization of equimolar amounts of bis(4‐methoxyphenyl) ether (1a) and formaldehyde proceeded homogeneously to afford the polymer (2a) in 49% yield (Mn 2600, Mw/Mn 1.8). From the FTIR, 1H‐NMR, and 13C‐NMR spectra of 2a, it was evident that the polymer had methylene moieties‐bridged repeating units in the polymer backbone. A higher molecular weight novolac (2a′) (yield 99%, Mn 16,600, Mw/Mn 12.9) could be prepared by using an excess of formaldehyde. Bis(4‐methoxyphenyl) sulfone novolac (2b) (Mn 1300, Mw/Mn 1.2) and bis(4‐methoxyphenyl) sulfide novolac (2d) (Mn 1200, Mw/Mn 1.9) were also prepared. However, the polymerization of bis(4‐hydroxyphenyl) sulfone (1c) did not proceed, even when it was attempted under various reaction conditions. From TGA, the temperatures at 10% loss in weight (T10) for 2a, 2a′, and 2b were found to be 413, 430 and 393°C, respectively. These results suggested that heteroatom‐bridged novolacs based on phenol derivatives have good thermal stability than other organosoluble polymers; moreover, these novolacs could be expected to function as processable materials, polymer blends for engineering plastics, etc. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009