The company announced plans in March to sell the business as it looks to focus on faster-growing sectors, such as feed additives and rubber silica for tyres.
Evonik and its adviser Barclays have started sending out first information packages to prospective bidders for the unit, which is seen fetching around 2.5-3 billion euros ($2.9-$3.5 bln), the people said.
Potential suitors are to receive detailed information after the summer, and first bids will be due several weeks after that, they added.
Peers such as South Korea's LG Chem and SK Holdings, China's Wanhua Chemical Group and Saudi Arabia's Sabic are being contacted about their potential interest, as well as U.S. chemicals firms LyondellBasell and DowDuPont, they added.
Separately, private equity investors with an interest in chemicals assets such as Advent, Carlyle, Blackstone and Apollo are seen as likely to participate in the auction, they added.
Evonik said its efforts to divest the business were on track but declined to provide further details. The potential suitors declined to comment or were not immediately available.
The business up for sale posted 2017 earnings before interest, tax, depreciation and amortisation of less than 400 million euros on 1.8 billion euros of sales from clear acrylic sheets and methacrylate chemicals, the people said.
"2017 was the top of the cycle and Evonik benefited from capacity outages at peers," a person close to the matter said, adding overhead costs also needed to be taken into account when looking at the business on a standalone basis, while allowing for some synergies.
The people said bidders would likely offer 2 to 2.5 billion euros for the asset, including debt, or 7 to 8 times the unit's expected adjusted core earnings, while the seller was hoping to bag up to 3.5 billion.
Shares in Evonik, which is controlled by a state-backed foundation, lags peers such as BASF, Lanxess and DSM as a multiple of expected core earnings.
Polymethyl methacrylate (PMMA) is used in the construction, automotive and electronics industries and known by brand names such as Plexiglas.
($1 = 0.8538 euros)
(Editing by Maria Sheahan and Mark Potter)
By Arno Schuetze and Matthias Inverardi