Page 149 - Handbook of Adhesion Promoters

142 Selection of Adhesion Promoters for Different

8.3 CELLULOSE AND ITS DERIVATIVES

Many commercial additives are suggested by their manufacturers for the improvement of
adhesion of cellulose and its derivatives. These include Amplify EA 100 & 101 and GR
204 &205, Chartwell C-515.4, Eastman G-3015, Regalite R1090 hydrocarbon resin, and
Uniplex 260.
The surface of cellophane (regenerated cellulose) was used to evaluate the effect of
specific interatomic bonding because its surface was smooth and offered no opportunities
1
for mechanical penetration and interlocking. The adhesion of formaldehyde resin to cel-
lophane was still strong after soaking in water or alkali, most likely because of formation
of covalent bonds between the resin and the cellulose (aldehyde group formation in the
1
cellulose followed by condensation with reactive groups in the resin).
In pharmaceutical applications of adhesion of cellulose film to tablet, Hansen solu-
bility parameters have been used long time ago to predict not only adhesion but also
2
potential mode of failure. When the interaction parameter was close to unity then interfa-
cial failure was not possible because the interfacial bond strength was greater than the ten-
2
sile strength of the weaker component. In the opposite case, when the interaction
parameter was significantly lower than unity, the interfacial failure occurred even in per-
2
fectly bonded systems.
The cationic polyelectrolyte (poly[[2-propionyloxy)ethyl]trimethylammoniumchlo-
3
3
ride] in the reported study ) adsorbs onto the cellulose surface. Before the adsorption has
3
reached equilibrium, the adhesion between the surfaces was high. After a longer adsorp-
tion time, an electrostatic repulsion and no adhesion were observed between the polyelec-
3
trolyte-coated cellulose surfaces because of formation of the repulsive double layer.
The contribution of the acid-base component of surface free energy to the total sur-
face free energy of cellulose derived synthetic polymers ranged from 4 to 12%, which was
4
considerably lower than that of cellulose. The cellulose ethers demonstrated near monop-
4
olarity and had dominant electron donor (Lewis-base) character. The cellulose ether films
4
were predominantly electron donating. The work of adhesion of these polymers to vari-
4
ous substrates depended on acid-base contribution.
A reaction product of diacrylate diol (e.g. hexanediol, dipropylene glycol, etc.) 1-
methoxy-2-propyl acetate, 3-aminopropyltrimethoxysilane, and triethylenetetramine was
5
used as an adhesion promoter for coatings on cellulose products.
Cellulose acetate butyrate and cellulose acetate propionate were used as adhesion
6
promoters in UV-curable nail coatings.
REFERENCES
1 Dean, RB, J. Colloid Sci., 6, 4, 348-53, 1951.
2 Rowe, RC, Int. J. Pharm., 41, 219-22, 1988.
3 Osterberg, M, J. Colloid Interface Sci., 229, 620-7, 2000.
4 Luner, PE; Oh, E, Colloid Surf. A: Physicochem. Eng. Aspects, 181, 1-3, 31-48, 2001.
5 Nagelsdiek, R; Gobelt, B; Omeis, J; Freytag, A; Greefrath, D, US20120183787, Byk-Chemie GmbH,
Jul. 19, 2012.
6 Vu, T; Conger, C; Larsen, DM; Valia, D; Schoon, DD, US8901199, Creative Nail Design, Inc., Dec. 2,
2014.