Chemical foaming agent , additive

Using a laboratory technique previously developed to evaluate the performance of chemical foaming agents in XLPE foam, metallocene polyolefins are evaluated at various addition levels to branched LDPE to determine their effect on general foam quality (cell size, density, appearance). The laboratory method is discussed, and conclusions on acceptable levels of the metallocene resins are offered. 5 refs. 

Thermally stable foam additives, such as alkylaryl sulfonates and C -C g alpha-olefin sulfonates, are being used in EOR steam flooding for heavy od production. The foam is used to increase reservoir sweep efficiency (178,179). Foaming agents are under evaluation in chemical CO2 EOR flooding to reduce CO2 channeling and thus increase sweep efficiency (180). 

As it turned out, CFCs were ideal for the purpose. The members of this chemical family are nonflammable, noncorrosive, nontoxic, odorless, and very stable. Within a short period, they became widely popular for a variety of industrial applications. In addition to their applications in refrigeration systems, they became popular as aerosol propellants, cleansing agents for electrical and electronic components, and foaming agents in the manufacture... 

E-A. Tomic, USP 3713919(1973) CA 78, 126468(1973) (Chemical foaming of waterbearing expls with N,Nf-DinitrosopentamethyI-enetetramine. A typical gelled or emulsified aq blasting agent is sensitized by addition... 

In addition to the basic plastics in liquid and bead forms with foaming agents, fillers, additives that include cell controllers and fire-retardants, catalysts, surfactants, styrene monomer, systems that vary viscosity from liquid to paste form, and other additives are used. The gas can be put directly in to the plastic before the plastic solidifies. Reactant chemicals can be put in the plastic formulation that during polymerization will release a gas and produce the foam. 

The proper balance between viscosity and gas evolution can be controlled by a number of factors such as a suitable type and concentration of catalyst and surfactant, the presence of a nucleating agent (not always necessary) (17,18) and control of reaction temperature (or exotherm). Additional factors that must be considered are the use of a suitable chemical blowing agent, which is especially important for the production of thermoplastic foams, and the formation of oligomers (prepolymers) which exhibit higher viscosities than monomers in the preparation of thermoset foams (e.g. polyurethane foams). 

Additives and Fillers for Structural Foam Chemical Blowing Agents Processing Structural Foam Tooling... 

---