High Performance Polymers in Ionic Liquids: A Review on Prospects for Green Polymer Chemistry. Part I: Polyamides

The introduction of cleaner technologies has become a major concern worldwideand therefore, the search for alternatives to the unsafe volatile solvents hasbecome the greatest priority throughout the academy and industry. Due toenforcement of policies in protecting the environment, green chemistry has receivedmuch attention since 1990 s which it is still progressing. Green chemistry is understoodto be a superior, innovative chemistry which is cost-effective and has minimumdeleterious impact on environment. Highly polar conventional solvents such as N,N -dimethylformamide, N,N -dimethylacetamide, pyridine, N-methylpyrrolidone andchlorinated solvents which are used in polycondensation polymerizations are volatileand most of them are flammable, toxic, quite hazardous and harmful compared to ionicliquids (ILs). Hence, there is a basic obligation for the advancement of new methodologiesof polymerizations by using environmentally benign media which could replacethe conventional solvents and enhance adequate solubility for polymerizationprocesses. Ionic liquids have great potential as a non-volatile organic medium forpolymerization and polymer processing due to their near-zero vapour pressure,nonflammability, low cost and ease of production. However, implementation of ILs assolvents for polymerization processes has afforded some marked advantages such asincreased molecular weight and narrower polydispersity in comparison to organicsolvents. Owing to their higher performance and characteristics, the demand forhigh-performance polymers is growing steadily. Hence, the synthesis and properties ofhigh-performance polyamides in the green media using ILs are reviewed to develop amethodology for green polymer chemistry.