Global Polyacrylonitrile Market By Type (Acrylic Staple Fiber , Acrylic Tow , and Acrylic Top), By Application (Filtration , Textiles , Precursors to carbon fiber , Outdoor , and Fiber-reinforced concrete), By Region, and Key Companies - Industry Segment Outlook, Market Assessment, Competition Scenario, Trends and Forecast 2019-2028