Polymer systems in geothermal applications

Abstract

SynopsisThe feasibility of using a copolymer composed of styrene, acrylonitrile, and acrylamide or methacrylamide in the formation of a high-strength thermally and chemically stable polymer concrete for use in geothermal environments has been demonstrated. Specimens produced with the copolymer in conjunction with an aggregate containing sand and portland cement had compressive strengths in the range of 25,000 to 30,000 psi a t 2OoC and were thermally stable up to -24OOC. A study of the effect of monomer concentration on the properties of the polymer concrete indicated that the optimum concentration is in the range of 12 to 13 wt. %. Increased monomer concentrations lead to a nonuniform polymer distribution within the composite, resulting in a deterioration of the properties. The optimum properties are obtained when the monomer is used in conjunction with a n aggregate containing 70 to 80 wt. % silica sand and 20 to 30 wt. % portlqd cement. The results from laboratory and field evaluations in progress indicate that the materials can be used for pipe or as protective liners on pipe and vessels in electric generating and direct utilization geothermal processes.

Influence of the ratio of styrene and acrylonitrile in crosslinked polymeric binders for use in high‐temperature polymer concrete composites

“…The physicochemical properties of the monomers used in the development of PC composite materials were described earlier. 2 It has also been ~h~w n~>~ that a silica sand mixture that is part of the aggregate composition consisting of 50 parts by weight of sieve opening 1180 pm, 25 parts of 600 pm, and 25 parts of 150 pm has the proper particle size distribution for producing a high-quality PC with a minimum polymer content. Type I11 portland cement is added to this mixture to enhance the resistance to brine and steam.…”

Impregnation of mortars with monomers and their radiolytic polymerization

“…Accordingly, numerous applications have been reported, and many others are still under investigation. 15 Complete hydration of cement to achieve the ultimate strength needs several years; but, after 28 days, cured concrete reaches about 80% of the ultimate strength, and, as stated by Steinberg et a1. : it contains 3.5% by weight hydrated water (chemically combined water) and about 3.5% free water.…”

“…Concrete-polymer materials, on the other hand, have outstanding strength and durability and can be used as a materials of construction for such applications as reactors, nuclear technology, highways and bridge decks, pipes, desalination plants, marine use, storage bunkers for explosive chemicals and military applications. 15 Extensive work was carried out on composites formed by polymerization of monomers with cement (or concrete) as aggregates (known as polymerconcrete composites, PC) and by adding a monomer to a fresh concrete mixture which is subsequently cured (known as polymer-portland cement concrete, PPCC). While the first type is expensive and its strength decreases with temperature, the second type gives modest strength.…”

Corrosion of polymer–concrete composites in hydrochloric acid at elevated temperature

“…Also, the results indicated that the PC material has good durability in hot brine solutions and steam, a t temperatures up to 250°C. 9 Furthermore, it was also shown that PC composites have durability and chemical resistance to 0.36% (0.1N) HCl solutions. 'O In that investigation, composites consisting of 55 wt % styrene (St)-36 wt % acrylonitrile (ACN)-9 wt % trimethylolpropane trimethacrylate (TMPTMA), in conjunction with a sand-cement filler in a ratio of 9:1, were exposed to 0.36% HC1 for 1000 days at 90°C.…”