Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 8, pp. 1287−1291.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © R.Yu. Galimzyanova, M.S. Lisanevich, Yu.N. Khakimullin, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 8,
AND POLYMERIC MATERIALS
Effect of Calcium Carbonate on the Properties of Noncuring
Sealants Based on Butyl Rubber and Thermoplastics
R. Yu. Galimzyanova, M. S. Lisanevich, and Yu. N. Khakimullin
Kazan National Research University of Technology, Kazan, Tatarstan, Russia
Received April 9, 2013
Abstract—The effect of the content, dispersity, and surface polarity of calcium carbonate on the physicomechani-
cal and rheological properties of ﬁ lled noncuring hot melt sealant formulations based on butyl rubber and various
thermoplastics was examined. In the formulations based on nonpolar polymers, the cohesion strength and viscosity
increase with an increase in the content and dispersity of calcium carbonate, with the strongest reinforcing effect
observed with hydrophobized grades of calcium carbonate. With an increase in the polarity of the polymer base,
untreated natural carbonate (chalk) becomes more efﬁ cient.
The development of new and modiﬁ cation of existing
ﬁ llers open wide possibilities for improving the properties
of polymeric compounds. One of such ﬁ llers is calcium
carbonate, both natural (chalk, marble) and chemically
precipitated. The assortment of the latter is now expand-
ing as a result of the development of new preparation and
Calcium carbonate is attractive for the development
and processing of polymeric compounds for several rea-
sons [1, 2]: it is free of heavy metals, is nontoxic, has no
taste and odor, and is admissible for contact with food;
if necessary, the particle size distribution of calcium car-
bonate can be readily controlled; coatings can be readily
deposited onto the particle surface to control the surface
polarity and improve the rheological properties; it is
possible to introduce calcium carbonate into a polymeric
compound in large amounts without considerable increase
in the viscosity.
Calcium carbonate is widely used as ﬁ ller in noncur-
ing and curable sealants based on elastomers and reactive
oligomers. The ﬁ ller content in their formulas is up to
60% and more .
Wide assortment of calcium carbonate used as ﬁ ller
allows optimization of the thermodynamic state of the
polymer–ﬁ ller interface, thus improving the calcium
carbonate dispersion in the polymer and hence the pro-
cessability and properties of the compounds.
These advantages of calcium carbonate make efﬁ cient
its use in noncuring sealants, in particular, in hot melt
sealants based on butyl rubber (BR).
We studied how the content, dispersity, and surface
polarity of calcium carbonate affect the physicomechani-
cal and rheological properties of ﬁ lled noncuring hot melt
sealants based on BR and various thermoplastics: ethyl-
ene–vinyl acetate copolymer (EVAC 11808-340, vinyl
acetate content 23–30%) and low-density polyethylene
(LDPE 15803-020). The effect of ﬁ llers was studied with
the formulation consisting (wt parts) of BR-1675N rubber
(100), Pn-6sh plasticizer (10), Rubrax (30), P-803 carbon
black (5), and EVAC or LDPE (20).
The following kinds of ﬁ llers were used: MTD-2 (Bel-
gorod deposit), Omyacarb 2X, Omyacarb 5X (Omya),
and Winnoﬁ l SPT (Solvay Chemicals); their main char-
acteristics are given in Table 1.
It should be noted that all the ﬁ llers we chose, except
Winnoﬁ l SPT chalk, are not hydrophobized. Hydropho-
bization of calcium carbonate is performed with the aim
to make the particles water-repelling, mainly using fatty
acids (e.g., stearic). In so doing, the ﬁ ller surface becomes
hydrocarbon-like and less polar. As a result, the level of