Novel Bio-based Poly(vinyl ether)s for Coating Applications
and 150 °C was done for one hour. For elevated temperature
curing, coated panels were placed into the oven shortly after
the solvent had evaporated from the ;lm. In addition to coated
steel panels, free ;lm specimens were prepared by casting ;lms
over Te;on™-laminated glass panels. Table 1 displays the properties of the coatings and free ;lms. In general, the coatings
produced were relatively ;exible and possessed sub-ambient
Tgs. Although the coatings possessed sub-ambient Tgs, they exhibited good solvent resistance as expressed by the number of
methyl ethyl ketone (MEK) double rubs.
Polymers Based on Eugenol
Eugenol is a major component of Ocimum, Cinnamon, and
Clove oils. 22 Eugenol is also a potential product from the
breakdown of lignin, and approximately 50 million tons of lignin is produced annually from the pulp and paper industries
worldwide. 23
Analogous to the monomer based on cardanol, eugenol ethyl
vinyl ether (EEVE) was produced from eugenol and 2-chloro-
ethyl vinyl ether. This monomer was readily polymerized by
cationic polymerization to produce a soluble polymer that was
a viscous, tacky liquid at room temperature with a Tg of ap-
proximately 2 °C. Using proton nuclear magnetic resonance
spectroscopy, preservation of the allyl group derived from euge-
nol was con;rmed.
As illustrated in Figure 8, the methylene hydrogen atoms
between the vinyl group and the phenyl group should be very
labile to abstraction by singlet oxygen since the radical can be
resonance stabilized by both the adjacent double bond and
the phenyl ring. As a result, it was of interest to determine if
poly(EEVE) could be cured into a crosslinked ;lm by autoxidation. A poly(EEVE) sample with a number-average molecular
weight of 17,900 g/mol was dissolved in toluene at 35 wt.%.
To this solution, a drier package containing cobalt 2-ethylhex-
anoate, zirconium 2-ethylhexanoate, and zinc carboxylate was
added. With this system, a cast ;lm became dry-to-touch in 10
min, Coating specimens were produced using three different
curing conditions, i.e., curing at room temperature for 3 weeks,
120 °C for 1 h, and 150 °C for 1 h. In addition to ;lms cast on
steel substrates, free ;lms were produced and used to determine
;lm mechanical and viscoelastic properties. Table 2 shows the
properties obtained for the coatings and ;lms produced.
Figure 7. Schematic illustrating cardanol ethyl vinyl ether synthesis.
Table 1. Data for cured ;lms of poly(cardanol ethyl vinyl ether).
Figure 8. Illustration of resonance stabilization of a radical generated by
hydrogen abstraction by singlet oxygen.
