A 47-year-old man was taken to Queen Alexandra Hospital in Cosham after the assault in High Street, Lee-on-the-Solent, at 4am on May 3.
The man, who was on his way to work, is still in hospital being treated, police have said.
Detectives have released the e-fits in a bid to find the men.
Investigating Officer Detective Sergeant David West said: ‘I am issuing two e-fit images in the hope of speaking to these two men about this incident.
‘We have spoken again to the victim who has updated the descriptions we had previously issued to help us to prepare these images.
‘The investigation is progressing to establish the exact circumstances of what has happened and specialist resources from Hampshire Fire and Rescue Service were deployed as a precaution to enable officers to identify the nature of the liquid that the victim described.
‘Preliminary examination of samples recovered from the scene suggests that the liquid was Sodium Hydroxide, which is also known as caustic soda.
‘This substance does not present a wider risk to the local community.
‘The victim was taken to hospital to be treated for injuries to his face, where he remains.’
One suspect was white, 5ft 8ins, of medium build, had blue eyes, dark hair and had beard following his jaw line.
He was in his early 20s, was wearing a blue or black tracksuit with a QPR emblem on the left shoulder, and white trainers. He had black dots tattooed on his fingers and spoke with a strong Scottish accent.
The second suspect was white, white, 5ft 3ins tall, in his late teens, had red cheeks and was clean shaven.
He was wearing blue jeans, a black and white striped collared shirt under a black hooded bomber jacket and had pierced ears and was wearing studs.
He spoke with a slight Scottish accent.
Anyone with information should call 101 quoting 44160165297.