La Scala, John J. published the artcileEffect of methyl and methoxy substituents on dianilines for thermosetting polyimide system, Category: quinuclidine, the publication is High Performance Polymers (2020), 32(7), 801-822, database is CAplus.
4,4-Methylenedianiline (MDA) is widely used in high-temperature polyimide resins, including polymerization of monomer reactants-15. The toxicity of MDA significantly limits the manufacturability using this resin. Modifying the substitution and electronics of MDA could allow for the reduction of toxicity while maintaining the high-performing properties of the materials derived from the modified MDA. The addition of a single Me substituent, methoxy substituent, location of these substituents, and location of the amine relative to the phenolic bridge were modified as were other non-aniline diamines. Various anilines were condensed with paraformaldehyde under acidic conditions to yield dianilines. These dianilines and diamines were reacted with nadic anhydride and 3,3,4,4-benzophenonetetracarboxylic dianhydride in methanol to form the polyamic acid oligomers and heated at elevated temperature to form polyimide oligomers. It was found that the mol. weight of the oligomers derived from MDA alternatives was generally lower than that of MDA oligomers resulting in lower glass transition temperatures (Tgs) and degradation temperatures Addnl., methoxy substituents further reduce the Tg of the polymers vs. Me substituents and reduce the thermal stability of the resin. Methyl-substituted alternatives produced polyimides with similar Tgs and degradation temperatures The toxicity of the MDA alternatives was examined Although a few were identified with reduced toxicities, the alternatives with properties similar to that of MDA also had high toxicities.
High Performance Polymers published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Category: quinuclidine.
Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider