Polymer composites and films comprising reactive additives having thiol groups for improved quantum dot dispursion and barrier properties

A polymer composite having dispersed therein quantum dots wherein the polymer composite comprises of [a] 0.001-5 wt% of quantum dots, preferably cadmium-free quantum dots; [b] 0.5-40 wt% of polymerised units of a first compound comprising from 1-6 thiol groups and preferably having a molecular weight of 300-20,000 and having at least one continuous acyclic hydrocarbyl chain of at least three carbon atoms, such as thiolethylamide of 12-hydroxystearic acid or the thiolethylamide of oligo (12-hydroxystearic acid); and [c] 55-94.999 wt% of polymerised units of a second compound having a molecular weight from 100-750 and comprising at least two polymerisable vinyl groups as part of a (meth) acrylate ester group or attached directly to an aromatic ring, such as tricyclodecane dimethanol diacrylate, isobornyl dimethacrylate, divinyl benzene or mixtures thereof and, wherein the molecular weight of the first compound minus the molecular weight of the second compound is at least 100. The polymer composites provide more stably dispersed and durable quantum dot compositions for use in, for example, display devices.