• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.517-526
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• 1990

The crystal structures of two alditol acetates, D-glucitol hexaacetate and xylitol pentaacetate, have been determined by diffraction methods with Mo-K$\alpha$radiation, using direct methods for phase determinations. The crystal data are: for D-glucitol hexaacetate, P2$_1$, with a = 10.275 (2), b = 8.363 (1), c = 12.560 (5) $\AA;\beta$ = 95.97 $(2)^{\circ}$, Z = 2; for xylitol pentaacetate, P2$_1$/C with a = 18.126 (1), b = 11.422 (2), c = 8.649 (1) $\AA$, $\beta = 95.03 (1)^{\circ}$, Z = 4. Both molecules have extended zigzag carbon chain conformations which differ from previous studies of the structures of D-glucitol and xylitol and also differ from NMR studies on alditol acetates. The bond lengths and angles are normal, with mean values over both structures of C($sp^3)-C(sp^3): 1.514 (10),\; C(sp^3)-O: 1.444 (6),\; C(sp^2)-O: 1.347 (9),\; C(sp^2)=O: 1.197 (6),\; C(sp^2)-C(sp^3): 1.479(9){\AA},\; C(sp^3)-C(sp^3)-C(sp^3): 114.6 (17),\; O-C(sp^3)-C(sp^3): 109.4 (23),\; C(sp^2)-O-C(sp^3): 117.4 (6),\; O=C(sp^2)-O: 122.6 (6),\; C(sp^3)-C(sp^2)-O: 111.8 (7),\; C(sp^3)-C(sp^2)=O: 125.5 (4)^{\circ}$. The atoms of acetate groups are in coplanar. There are no particularly short intermolecular contacts and the molecules are held together by van der Waals force only.

• Journal of Adhesion and Interface
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• v.23 no.2
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• pp.25-32
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• 2022

There has been a growing demand for water based-type PSA due to environmental regulations for solvent-type PSA. And accordingly, there is a growing expectation as well for tackifiers used to compensate for the problem of deterioration of physical properties. Therefore, In this study, water-based tackifiers were synthesized by changing the contents of hard and functional acrylic monomers CHMA, IBOA, and AA. And these were added to the pressure-sensitive adhesive at 10 phr and their physical properties were compared. Tackiness slightly decreased as CHMA increased and IBOA decreased. Since the intermolecular bonding force increased due to the increase in AA content, the lower the AA content showed better results. Peel strength increased as the tackifiers were added because the fluidity of the polymer chain increased. And higher AA content showed better results because more hydrogen bonds were formed. The holding power tended to decrease as CHMA increased because the content of IBOA relatively decreased which has a large influence on the holding power. And higher AA content showed better results.