MASTICATING AGENT

Properties Wh. cryst. powd. m.w. 171.30 sp.gr. 0.967 m.p. 71-76 C b.p. 238 C flash pt. 50 C Toxicology Harmful by ing. causes burns NFPA Health 3, Flammability 1, Reactivity 0 Uses Light stabilizer mastication agent intermediate for medicine bleaching agent polymerization inhibitor epoxy crosslinking agent intermediate for UV stabilizers, other org. chems. 

Natural rubber which has been reduced to an easy flowing consistency by prolonged mastication in the presence of peptising agents. Suitably compounded, DPR may be cast into moulds and vulcanised ebonite products from DPR are also possible. 

Mechanical synthesis by cold mastication of rubber and monomers depends on the reaction condition (monomer concentration, temperature, solvent concentration, atmosphere, presence of transfer agents, or catalyst) and on the physical and chemical properties of the rubbers, the monomers and the product interpolymers. A critical factor is the shear stress developed in the system rather than instrumentally-defined shear rates. The degree of reaction of polymer and consequently also the concentration of free macroradicals depends on stress. As a consequence, the influence of the above parameters may be connected to their influence on the viscosity of the reaction medium since an increase in viscosity causes an increase in stress at constant shear rate. 

Fig. 16a-

The polymer was masticated in the internal mixer for 5 min then ZnO and stearic acid were added. Curing agents were added on a two-roll mill and dispersed during 15 min of milling. 

Exemplary materials for the waterproofing of masonry surfaces are waterproof membranes such as poly(vinyl chloride), PE, butyl rubber, and sealants such as tar, asphalt, paints, poly(urethane), epoxy or mastics. While these waterproofing agents can offer excellent resistance to water penetration and other contaminants, they can alter the appearance of the masonry surface, e.g., they may change the color of the surface or leave it with a shine. Waterproofing treatments can also trap moisture within the masonry surface and promote spalling. 

Attagel. [Engelhard] Atttqwlgite day drilling muds, paints, adhesives, sealants, and mastics. 

CF. [Qistom Fibers] Cellulose fibers reinforcing filler and vise, control agent for epoxy grouts, gasket material, mastics as asbestos replacement... 

Siivo Bond. [Unimin Specialty Minerals] Ground silica fill, flatting agent for paints, mastics, adhesives, bu g compds., elec, qroxy conq)ds. 

Thixseal. [Rheox] Casmr oil deriv. thixotrope, gellant for solv.-based systems si and slump control agent fix cauUa, sealants, and mastics. 

Unispar. [Unimin Specially Minerals] Feldspar fillers and flatting agents for traffo paint, interior/exterior atdiitec-turai coatings, protective, maintenance and marine coatii, mastics and adhesives. 

Pentachlorthiofenol Renacit 7 RPA 6 USAF B-51. Peptizer for natural rubber, polyisoprene, styrene/butadiene rubber, polybutadiene, NBR, bu l, chloroprene and blends absorbed on clay, used as a peptizing agent facilitating open rnill and internal mixer mastication in rubber industry, Mildly toxic by ingestion severe eye irritant. Akrochem Chem. Co. Bayer AG Polysar. 

---