Acrylic acid nonvolatile

Sulfosuccinic and sulfopropionic acids are economically attractive when synthesized in situ or offsite from maleic anhydride or acrylic acid. Both are subject to oxidation, but should give nonvolatile degradation products. Synthesis of sulfopropionic acid can give undesirable polyacrylic acid impurities. 

Many aliphatic acids, such as FO, AC, PRO, BUT, VAL, and rare-aromatic acids, such as BZ, were found in marine algae. The origin of these acids has not been reported. The origin of acrylic acid was shown to result from hydrolysis of dimethyl- S-propiothetin [82]. Nonvolatile fatty acid amounts in algae were previously published [97]. 

Acrylic Resin and Formulation. The acrylic resin was obtained commercially (Rohm and Haas QR-496) as a 70% solution in 2-butoxy-ethanol. The solvent was removed under vacuum, the final conditions being one hour at 120°C and 2 mm Hg. Typically 2000 grams of the resin as supplied yielded 1452 grams of 100% solids resin (72.1% non-volatile). Titration showed the product had an acid value of 36.8. A typical solids determination of the original solution gave 67.5% nonvolatile, indicating some residual monomer in the resin. 

Figure 11.26 PEB stability of a conventional DUV 248-nm resist based on poly (4-hydroxystyrene-co-tert-butylcarbonyloxy styrene) versus ESCAP based on poly(4-hyd-roxystryene-co-tert-butyl acrylate). Note that the acid generated in the conventional DUV resist is trifluoromethane sulfonic acid (a very strong, small, volatile acid), while that of the ESCAP resist is camphor sulfonic acid (a very weak, bulky, nonvolatile acid). While the conventional DUV resist polymer is nonannealing, that of the ESCAP is an annealing polymer. [Reproduced from R. Dammel, Practical photoresist processing, SPIE Short Course No. SC616 (2005).]...

The last-mentioned inhibitor is of particular interest. In the acid, it obviously exists as a nonvolatile salt that can act as a still-pot inhibitor when small amounts of acrylic or methacrylic acid have to be distilled under reduced pressure to prepare an inhibitor-free sample of the acids. 

---