Commercial acrylic

Hie common acrylic ester monomers are combustible liquids. Commercially, acrylic monomers are shipped with DOT red labels in bulk quantities, tank cars, or tank tmcks. Mild steel is the usual material of choice for the constmction of bulk storage facilities for acrylic monomers. Moisture must be excluded to avoid msting of the tanks and contamination of the monomers. Copper or copper alloys must not be allowed to contact acrylic monomers intended for use in polymerization because copper is an inhibitor (67). 

Over the years many attempts have been made to produce commercial acrylic polymers with a higher softening point than PMMA. The usual approach was to copolymerise MMA with a second monomer such as maleic anhydride or an N-substituted maleimide which gave homopolymers with a higher Tg than PMMA. In this way copolymers with Vicat softening points as high as 135°C could be obtained. 

The major commercial acrylates are formed from the alcohols that should by now be familiar to you—methanol, ethanol, butanol, iso-butanol, and 2-ethyl hexanol. The corresponding acrylates are shown in Table 19—1. 

Table 19-1 Commercial acrylates Acetylene to ethyl acrylate...

DuPont continued their leadership role in synthetic fibers by commercializing acrylic fibers (Orion) in 1950. They did a repeat performance in 1-953 with a polyester called Dacron. The big four fibers—Nylon 6, Nylon 66, acrylics, and polyester—now account for most of the synthetic production and about half of the fiber production of all kinds, including cotton, silk, and wool. 

Waegemaekers THJ, van der Walle HB a, P-Diacryloxypropionic acid, a sensitizing impurity in commercial acrylic acid. Der-matosen Beruj Umwelt 32 55, 1984... 

Most commercial acrylic sheets have an index of refraction of about 1.5 and a total luminous transmittance of about 90%. PC sheet has an index of refraction of about 1.6 and a total luminous transmittance of about 88%, Polysulfone sheet (IJdel) has an index of refraction of about 1.63 and a total luminous transparency of 80%. 

After dermal exposme, 4% acrylic acid resulted in marked skin irritation in three strains of mice (McLaughlin et al., 1995), while 1% in acetone was tolerated, i.e. a less pronounced irritative effect was observed. In a commercial acrylic acid sample, a.p-di-acryloxypropionic acid was identified as a strongly contact sensitizing constituent in guinea-pigs (Waegemaekers van der Walle, 1984). 

Some of the physical properties of the principal commercial acrylic esters are given in Table 2... 

Acrylics. The DuPont Company introduced the first commercial acrylic fiber, Orion, in 1950. Acrylics are made from the polymerization of acrylonitrile and other co-monomers to allow dyeability and to open the internal structure. The fibers are produced by either solventspinning (Orion), or wet-spinning (Acrilan). In the solvent-spinning process, the polymer is... 

FIGURE 48 SEM micrograph of matrix tablet containing potassium chloride as drug model and commercial acrylic-metacrylic copolymer. The white KCI particles are surrounded by an almost continuous dark gray mass of excipient. (Courtesy of M. Millan.)... 

The physical properties of the principal commercial acrylic esters are given in Table 4. A more comprehensive listing of physical properties, including other less common acrylates, is provided in the article Acrylic acid AND DERIVATIVES. 

Table 5.7 Physical properties of commercial acrylic emulsions used as cement modifiers...

B) Similarly, as the length of the ester side chain increases, segmental rotations in the side chain, as well as an increase in the specific volume of the polymers, result in freer segmental motion within the polymer chain, with a concomitant decrease in tensile strength and an increase in the extensibility of the polymers (Table I). When one considers that commercial acrylic polymers are almost... 

Table 15.11. Commercial acrylic/impact modifier blends vs. acrylic...

This polymer, whose name is often abbreviated to PMMA, is the most important of the commercial acrylic polymers. These polymers are formally derived from poly(acrylic acid), [—CH2CH(C02H)—] . In the case of PMMA, this derivation... 

The composition and process details of most commercial acrylic and styrene-acrylic latexes are proprietary, and there is such variety that it would be difficult to select one or two as typical examples. A sampling of polymerization processes from the patent literature follows an acrylic latex for aqueous... 

The situation changed dramatically when DuPont introduced the first commercial acrylic fiber under the trade name of Orion. This commercial development took place shortly after DuPont [12] and I.G. Farbenindustrie [13] simultaneously reported solvents suitable for spinning acrylonitrile fibers in 1942. Based on this solvent breakthrough, DuPont was able to develop a commercial process for producing acrylic fibers. The DuPont process was based on dry spinning with A,A-dimethylformamide (DMF) as the solvent. The product was introduced in 1944 as Orion. Shortly thereafter Chemstrand (later to become Monsanto Fibers and Intermediates Company) introduced Acrilan, Siiddeutsche Chemiefaser (Hoechst) introduced Dolan, and Bayer introduced Dralon. Developments in this fledgling industry occurred rapidly from that time on. 

FIGURE 12.9 X-ray diffraction patterns of (a) commercial acrylic and (b) polyethylene terephthalate fibers. The acrylic fiber was a commercial sample containing 7% vinyl acetate comonomer. In both cases, the fiber axis is vertical. 

Several experimental approaches have been applied for determining the fiber Tg under hot wet conditions [199-203]. Aiken et al. [199] compared the Tg of a commercial acrylic yarn in the dry state and in water using dynamic-mechanical analysis, and observed a reduction from 92 to 72°C. Bell and Murayama [200] observed that the Tg of a commercial AN-NA copolymer decreased from 128°C when dry to 80°C in a 100% relative humidity atmosphere. Gur-Arieh and Ingamells [201] related the extension in length of Acrilan filaments to a Tg reduction and showed a shift from a 90°C in air to 57°C in water. Finally, Hori et al. [202] used DSC to show that the Tg of four kinds of acryhc fibers decreased with increasing water content and approached an almost constant value for all four fibers. 

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