Asphalt adhesion

D 3747 Specification for Emulsified Asphalt Adhesive for Adhering Roof Insulation... 

Styrene-containing block copolymers are commercially very important materials. Over a billion pounds of these resins are produced annually. They have found many uses, including reinforcement of plastics and asphalt, adhesives, and compatibilizers for polymer blends, and they are directly fabricated into articles. Most styrene-containing block copolymers are manufactured using anionic polymerization chemistry. However, anionic polymerization is one of the more costly polymerization chemistries because of the stringent requirements for monomer and solvent purity. It would be preferred, from an economic cost perspective, to have the capability to utilize free radical chemistry to make block polymers because it is the lowest cost mode of polymerization. The main reasons for the low cost of FR chemistry are that minimal monomer purification is required and it can be carried out in continuous bulk polymerization processes. 

There are two different bonding systems employed with the block a urethane asphalt adhesive/membrane or a special inorganic silica-based mortar. The choice depends on mechanical considerations and on the chemical and thermal environment. 

Urethane Asphalt Adhesive/Membrane A urethane asphalt elastomer serves as both an adhesive and a membrane to protect the substrate. It is a two-component material which bonds the blocks to each other and to carbon steel, alloy steel, concrete or other organic linings and also functions as a moisture and chemical-resistant barrier (or membrane) between the block and the substrate. 

Figure 17-2 Foamed borosilicate glass block and urethane asphalt adhesive/membrane over fiberglass reinforced plastic.

The insulating power and chemical resistance of the glass block allows for a thinner lining and better membrane protection for pickle tanks where stability is not a concern. The tank is first lined with the rubber membrane, the block is bonded over that with its urethane asphalt adhesive/membrane and finally a course of acid-resistant brick laid in acid-resistant mortar is placed over the block for mechanical protection. 

In the early 1970s, light, closed-cell foamed borosilicate glass block (see Chapter 17) were developed. These block, with a mass of only 12 Ib/cu.ft., will adhere to the underside of a concrete or steel cover by using a urethane asphaltic adhesive all joints between them are made the same way. Insulation of this type has been applied to the underside of both concrete and steel covers and has functioned successfully for a decade. 

Uses Antifoam for industrial applies., esp. latex, traffic paints, decorative paints for asphalt, adhesives, inks, wallcoverings defoamer in food-contact coatings, paper/paperboard food pkg. adhesives, coatings Features Silicone-free highly compat. in finished prod., no film defects Regulatory FDA 21 CFR 175.105,175.300,175.320,176.170,176.180, 176.200,176.210 EPA compliance... 

Fourier transform IR spectroscopy, SEM, energy dispersive X-ray spectroscopy and tensile testing were used to characterise a fully adhered EPDM roofing membrane which had exhibited surface degradation in the form of brownish staining and subsequent failure. The results suggested that the cause of the staining and failure could be attributed to the rubberised asphalt adhesive. 6 refs. 

Uses Antistripping additive for highway paving applies. asphalt adhesion agent Properties Dk. brn. vise, liq. sp.gr. 0.970 dens. 8.10 Ib/gal vise. 2450ops pourpt. 55 F flash pt. (COC) 320 F 100% act. 

TABLE 5.6 Physical Properties of FiberTite FTR 390 Rubberized Asphalt Adhesive [27]... 

Butyl rubber and asphalt adhesives compete in applications such as flashing applications. Table 5.8 shows a side-by-side comparison of those two adhesives indicating advantages for the butyl rubber over rubberized asphalt adhesive. 

TABLE 5.8 Comparison of Properties of Butyl Rubber and Rubberized Asphalt Adhesives [29]... 

Applications. These materials are stiU in developmental infancy. Current production is limited to one commercial process in Europe and a demonstration-scale process in North America. The lignins produced in these processes have potential appHcation in wood adhesives, as flame retardants (qv), as slow-release agents for agricultural and pharmaceutical products, as surfactants (qv), as antioxidants (qv), as asphalt extenders, and as a raw material source for lignin-derived chemicals. 

Fiber dmms can be produced to meet a wide variety of requirements. They can be constmcted with adhesives for water resistance, their interiors can be coated, their walls and ends can incorporate metal foil or asphalt-impregnated pHes, and their exteriors can be decorated by painting, varnishing, and silk screening for both ornamental and functional purposes. 

The use of petroleum or derived materials, such as asphalt, and the heavier nonvolatile cmde oils is an old art (2). In fact, petroleum utilization has been documented for more than five thousand years. The earliest documented uses occurred in Mesopotamia (ancient Iraq) when it was recognized that the nonvolatile derivatives (bitumen or natural asphalt and manufactured asphalt) could be used for caulking and as an adhesive for jewelry or as a mastic for constmction purposes. There is also documented use of bitumen for medicinal use. 

Interest in naphtha (nafta) began with the discovery that petroleum could be used as an illuminant and as a supplement to bituminous incendiaries, which were becoming increasingly common in warfare. Greek fire was a naphtha—bitumen (or naphtha—asphalt) mix the naphtha provided the flame and the bitumen (or asphalt) provided the adhesive properties that prolonged the incendiary effect. 

Dispersion at temperatures of 90—110°C is a common final step io European mills processiog wax-coated old cormgated containers. Dispersion temperatures less than 90°C are reported to reduce wax particle size to improve pulp drainage properties on paper machines while improving paper strength (45). Dispersion has been used to reduce hot-melt adhesive, plastic coating, and asphalt particle size. These low density particles can then be removed from the pulp by flotation (46). 

Built-Up Roofing. Built-up roofing (BUR) is a continuous-membrane covering manufactured on-site from alternate layers of bitumen, bitumen-saturated or coated felts, or asphalt-impregnated glass mats and surfacings. These membranes are generally appHed with hot bitumens or cold apphed bituminous adhesives (qv). 

Procedures for testiug asphalt shingles resistant to wind blowup/blowoff when appHed on low slopes in accordance with manufacturer instmctions. Shingles are Type I, factory-appHed adhesive (self-sealing shingles) and Type II, lock-type, with mechanically interlocking tabs (ears). 

The modulus of elasticity can also influence the adhesion lifetime. Some sealants may harden with age as a result of plasticizer loss or continued cross-linking. As a sealant hardens, the modulus increases and more stress is placed on the substrate—sealant adhesive bond. If modulus forces become too high, the bond may faH adhesively or the substrate may faH cohesively, such as in concrete or asphalt. In either case the result is a faHed joint that wHl leak. 

Pa.ints, Paints (qv) prepared from poly(vinyl acetate) and its copolymers form flexible, durable films with good adhesion to clean surfaces, including wood, plaster, concrete, stone, brick, cinder blocks, asbestos board, asphalt, tar paper, wahboards, aluminum, and galvani2ed iron (147). Adherence is also good on painted surfaces if the surfaces are free from dirt, grease, and mst. Developments in emulsion polymeri2ation for paint latices have been reviewed (148). 

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