JOURNAL OF
POLYMER SCIENCE
ARTICLE
WWW.POLYMERCHEMISTRY.ORG
8 Chemistry and Technology of Cyanate Ester Resins; I. Hamer-
ton, Ed.; Blackie A&P: Glasgow, 1994.
to V-0 by blending, requiring only 10 wt% in the case of
dicyanate 2. Our study showed that phosphorus was indeed
a suitable heteroatom with which to build intrinsically flame
resistant cyanate esters. The only other V-0 rated cyanate
esters contained fluorine or sulfur, the dicyanates of bisphe-
nol AF and 4,40-thiodiphenol, respectively.54
9 A. Kandelbauer, In Handbook of Thermoset Plastics, 3rd ed;
H. Dodiuk, S. H. Goodman Eds.; Elsevier: New York, 2014;
Chapter 11, pp 425–458.
10 P. M. Hergenrother, C. M. Thompson, J. G. Smith, Jr., J. W.
Connell, J. A. Hinkley, R. E. Lyon, R. Moulton, Flammability of
epoxy resins containing phosphorus; Technical Report DOT/
FAA/AR-TN05/44, November 2005.
The para isomer appeared to be hygroscopic and will require
more attention to conditions of isolation and storage. The
two meta configured 2 and 3 did not, or were less prone to,
pick up water when stored under ambient conditions. These
phosphine oxide containing cyanate esters will likely require
more attention to atmospheric moisture during processing
and composite construction. This issue with water stems
from the polar phosphine oxide moiety and this phenomenon
appears not to have been discussed, as it relates to poly-
mers, in any detail until now.55 This will be important to
examine more thoroughly since phosphorus compounds such
as triarylphosphate ester are the new, halogen-free additives
industry uses to flame retard commodity plastics.56
11 D. M. Knauss, J. E. McGrath, T. Kashiwagi, In Fire and Poly-
mers II: Materials and Tests for Hazard Prevention; G. L. Nel-
son, Ed.; American Chemical Society Symposium Series
599; American Chemical Society: Washington, DC, 1995; pp 41–
55.
12 M. Ito, H. Hirose (Sumitomo Bakelite Company) Japanese
Patent 2000186186, July 4, 2000.
13 Y.-L. Liu, G.-H. Hsiue, R.-H. Lee, Y.-S. Chiu, J. Appl. Polym.
Sci. 1997, 63, 895.
14 ASTM D3801-10, Standard Test Method for Measuring the
Comparative Burning Characteristics of Solid Plastics in a Verti-
cal Position; ASTM International: West Conshohocken, PA,
15 A. Casares, In Fire-Resistant Materials: Progress Report; R.
E. Lyon, Ed.; Technical Report DOT/FAA/AR-97/100, November
1998; pp 83–90.
Future work will include more precise water absorption
studies of the phosphorus-containing cyanate esters and pol-
ycyanurates. Making larger quantities of dicyanate 2 will
allow for further testing in flame retarding the various other
commercial cyanate ester products. Combustion calorimetry
and limiting oxygen index would be good means to quantify
the heat release capacity and flammability of the new resins
and their blends. The dielectric constant and loss of the
phosphorus-cyanate esters should be measured since cyanate
ester are often used in the manufacture of radomes and
printed circuit boards.
16 J. C. Abed, R. Mercier, J. E. McGrath, J. Polym. Sci. Part A:
Polym. Chem. 1997, 35, 977.
17 Y. Tada, T. Inoue, S. Moriya (Fushimi Pharmaceutical Co.)
Japanese Patent 2008088079, April 17, 2008; Chem. Abstr.
2008, 148, 468736.
18 S. Itoh, E. Fukasawa, Y. Ueno, M. Yaginuma (Mitsubishi Gas
Chemical Co.) U.S. Patent 9,394,439 B2, July 19, 2016.
19 C. H. Lin, K. Z. Yang, T. S. Leu, C. H. Lin, J. W. Sie, J.
Polym. Sci. Part A: Polym. Chem. 2006, 44, 3487.
20 S. Toranosuke, M. Kitani, H. Ohishi (Sanko Kaihatsu, Kagaku
Kenkyusho) U.S. Patent 4,618,693, October 21, 1986.
ACKNOWLEDGMENTS
21 Millipore-Sigma, Catalog Number CDS025166, 50 mg/$26.
22 A. Gavezzotti, J. Chem. Soc. Perkin Trans. II 1995, 1399.
Financial support from the Office of Naval Research and the Air
Force Office of Scientific Research are gratefully acknowledged.
Thanks to Mary Ray and Mara Bowen of the NAWC Technical
Library (China Lake) for collecting several of the literature
citations.
23 A. R. Katritzky, U. Maran, M. Karelson, V. S. Lobanov, J.
Chem. Inf. Comput. Sci. 1997, 37, 913.
24 A. C. Holler, J. Org. Chem. 1948, 13, 70.
25 Prudent Practices in the Laboratory: Handling and Disposal
of Chemicals; National Academy Press: Washington, DC, 1995;
pp 288–289.
REFERENCES AND NOTES
26 P. Patnaik, A Comprehensive Guide to the Hazardous Prop-
erties of Chemical Substances, 3rd ed.; John Wiley & Sons:
New York, 2007; pp 328–329.
1 M. R. Kessler, J. Polym. Rev. 2012, 52, 229.
2 Manufacturing Techniques in Polymer Matrix Composites
(PMCs); S. G. Advani, K-T. Hsiao Eds.; Elsevier: New York,
2012.
27 R. P. Pohanish, Sittig’s Handbook of Toxic and Hazardous
Chemicals and Carcinogens, 6th ed.; Elsevier: Oxford, 2012; pp
802–804.
3 P. K. Mallick, Processing of Polymer Matrix Composites:
Processing and Applications; CRC Press: New York, 2017.
28 SAINT and SADABS, Bruker AXS, Inc.: Madison, WI, 2014.
29 G. Sheldrick, Acta Crystallogr. Sect. A: Found. Crystallogr.
2015, 71, 3.
4 Composite Materials for Aircraft Structures; A. A. Baker, S.
Dutton, D. Kelly Eds.; American Institute of Aeronautics and
Astronautics: Reston, VA, 2004.
30 G. Sheldrick, Acta Crystallogr. Sect. C: Cryst. Struct. Com-
mun. 2015, 71, 3.
5 R. Walters, R. E. Lyon, Calculating polymer flammability from
molar group contributions; Technical Report DOT/FAA/AR-01/
31, September 2001.
31 A. E. Senear, W. Valient, J. Wirth, J. Org. Chem. 1960, 25,
2001.
€
32 C. M. Whitaker, K. L. Kott, R. J. McMahon, J. Org. Chem.
1995, 60, 3499.
6 E. Grigat, R. Putter, Chem. Ber. 1964, 97, 3012.
7 R. B. Graver, In High Performance Polymers: Their Origin and
Development; R. B. Seymour, G. S. Kirshenbaum Eds.;
Springer: Dordrecht, 1986; pp 309–316.
33 Combustion analysis (C,H,N) of hemihydrate or anhydride
are both within 0.4% of theoretical.
10
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018, 00, 000–000