Facile Synthetic Route Toward High Conversion Primary Aliphatic Poly(vinyl benzyl isocyanate) via Iodination

Abstract

Aliphatic isocyanato polymers, poly(vinyl benzyl isocyanate)s were synthesized via iodination and isocyanation from starting materials poly(vinyl benzyl chloride)s. This new process does not require phosgene which is highly toxic. This synthetic route takes advantage of the unique property of iodide ion which functions not only as a good nucleophile for iodination but also as a leaving group for isocyanation. The isocyanation conditions are mild with reaction temperatures ranging from 30 to 70 C. In addition, the process is very efficient with conversions over 90%, yielding no dimer, trimer or other byproducts.KEY WORDS: Poly(vinylbenzyl isocyanate) / Iodination / Isocyanation / TEMPO / Isocyanato functional groups are highly reactive toward amines and alcohols to form urea and urethane compounds, respectively. Extremely large amounts of polyurethanes (PUs) have been produced for daily necessities in various industries. In one example, PUs are used extensively in rigid and soft foams which are widely used in commercial products, and also capable of satisfying specific needs such as adhesives, coatings and sealants. Apart from that, isocyanato polymers have attracted lots of attention because of their wide range of applications. Synthesis of isocyanato polymers that contain polystyrene (PS) backbones falls into two categories.For the first category, one can directly polymerize the vinylcontaining isocyanato monomer such as m-isopropeny-, 0 -dimethylbenzyl isocyanate (TMI).