Tethis Inc. has raised $3.9 million in equity, according to a Tuesday filing with the Securities and Exchange Commission.

The money was raised by 75 investors.

The company is seeking to raise another $6.7 million to meet its goal of $10.5 million.

The Raleigh-based company creates polymers from bioderived feedstocks for use in the hygiene, personal care, oil and gas, water treatment, building materials and paper industries. It’s hoping to revolutionize the diaper industry, for example.

The company, started by two former North Carolina State University students, has spent the past five years developing a biodegradable alternative to the absorbent polymers used in diapers.

Tethis received an investment of $17.6 million earlier this month in Series C financing led by the Blue Hill Group of Chapel Hill, North Carolina.

The company has received past funding from the Wolfpack Investor Network and the Carolina Angel Network.

The company is led by Chief Executive Officer Scott Bolin and Executive Chairman Chris Evans.

Bolin launched Tethis in June of 2012, following its development as a project at N.C. State.

Companies relying on a Reg D exemption do not have to register their offering of securities with the SEC, but they must file what’s known as a Form D electronically with the SEC after they first sell their securities.