There's no Polaris service on that route. If you are talking about UA 340, that's generally a 3-class internationally-configured 777, but it's not branded as and does not include any Polaris "extras". It's domestic F. Nicer hard product, but still F.
Not even the UC access which goes with TCON premium.
That's the bad news. The good news is that there are tons of great food & drink options on the C-D concourse at IAD.