Stearic acid reinforcing fillers

Zinc salt of maleated EPDM rubber in the presence of stearic acid and zinc stearate behaves as a thermoplastic elastomer, which can be reinforced by the incorporation of precipitated silica filler. It is believed that besides the dispersive type of forces operative in the interaction between the backbone chains and the filler particles, the ionic domains in the polymer interact strongly with the polar sites on the filler surface through formation of hydrogen bonded structures. [Pg.450]

Use of fine particle size precipitated carbonate filler provides good reinforcing properties and also increases viscosity. Some fine particle size precipitated carbonates are coated with stearic acid to improve wetting. These fillers are desirable where a high pH is required in a compound. Fine particle size coated precipitated carbonates improve thixotropy of a compound. [Pg.135]

Chem. Descrip. Calcium carbonate, coated with < 2% stearic acid Chem. Analysis CaCOj (97.6%), MgCOs (1.5%), moisture (0.2% max.) Uses Coated pigment, filler, reinforcement with easy dispersion in plastic compds., e.g., polyolefins, rigid and flexible PVC, nat. and syn. rubbers and latexes for wire and cable insulation compds., water sealant compds., improved impact props, in PP hardens and stiffens stocks filler, pigment, reinforcing agent in paper, paints, caulks Features Flydrophobic disperses readily Regulatory NSF compliance... [Pg.463]

Both the ground and precipitated calcium carbonates can by treated with stearic acid to control water absorption, improve dispersabUity, and promote better wetting of the flUer by rubber. Silane treatment of these fillers is not effective. However, there is an ultra-fine grade coated with carboxylated polybutadiene, which reactively links to the particle surfaces. Such treated ultra-fine products can give reinforcement of about the same level of the semireinforcing thermal carbon blacks. [Pg.286]

Include at least 2 phr of stearic acid in the formulation as this acts as a retarder. Select less reinforcing fillers to reduce heat build up during process as the unfilled polymer has a tensile strength of 15-16 MPa. In this regard, keep the stock temperature low during processing. [Pg.83]

Chem. Descrip. Hydrogenated stearic acid, rubber grade Uses Intermediate, process aid in alkyd resins, rubber compding., water repellents, polishes, soaps, abrasives, cutting oils, candles, crayons, emulsifiers activator, plasticizer, softener, process aid for rubbers (mod. reinforcement, good disp.) dispersant for pigments and fillers... [Pg.580]

FIG U RE 11.1 Typical contour plot to abbreviate compounding data (Vistalon 3708/Ethylene-Propylene Terpolymer, Enjay Chemical Company, 1968). Note that a compound with 200 parts each of oil and filler per 100 parts of rubber by weight (phr) still has a strength of about 1000 psi (7 MPa), quite acceptable for many mechanical applications. The compound, based on a high-molecular-weight ethylene-propylene terpolymer, also contains 5 parts zinc oxide, 1 part stearic acid, 1.5 parts sulfur, 1.5 parts tetramethylthiuram disulfide, and 0.5 parts of benzothiazyl disulfide. Cross-linking takes place at 160°C for 20 min. SRF, Semi-reinforcing furnace. [Pg.451]

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