The number of chemical merger and acquisition deals in the U.S. picked up in the final quarter of 2013, buoyed by the favorable economy and optimistic profit forecasts, according to PricewaterhouseCoopers. Chemical M&A activity will likely continue to be strong in the coming months and will be driven by firms looking to divest their non-core business assets, said A.J. Scamuffa, U.S. chemicals leader at PwC.