Dear Student
The nodal industry for synthetic textiles and various other chemical industries is the Petroleum industry which includes exploration, extraction, refining, transporting and marketing of petroleum products such as fuel oil, gasoline, propane, distilled crude oil etc.
Thus, petroleum itself acts as a raw material for other industries as it provides for the basic manufacturing needs. Hence is a nodal industry for synthetic textiles as it involves usage of machinery and various chemicals.
Regards