144 hour free visa shanghai

I am flying on a return ticket with ba London to Shanghai and then Hong Kong to London. I have a separate ticket from Shanghai to Hoi an in Vietnam with air Macau which stops in Macau for 3 hours with a change of plane to Vietnam. I then fly Hanoi on a separate ticket to Hong Kong and then to the UK with ba . Do I need a visa for our 2 day stay in Shanghai?
Thank you