Braskem：债权人向法院提交针对间接子公司America Finance的非自愿Chapter 11申请

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13A-16
OR 15D-16 OF THE SECURITIES EXCHANGE ACT OF 1934

For the month of October, 2026

(Commission File No. 1-14862 )

BRASKEM S.A.

(Exact Name as Specified in its Charter)

N/A

(Translation of registrant's name into English)

Rua Eteno, 1561, Polo Petroquimico de Camacari
Camacari, Bahia - CEP 42810-000 Brazil

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F ___X___       Form 40-F ______

Indicate by check mark if the registrant is submitting the Form 6-K
in paper as permitted by Regulation S-T Rule 101(b)(1). _____

Indicate by check mark if the registrant is submitting the Form 6-K
in paper as permitted by Regulation S-T Rule 101(b)(7). _____

Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes ______       No ___X___

If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82- _____.

NOTICE TO THE MARKET

São Paulo, October 21, 2026 - Braskem S.A. ("Company") (Ticker B3: BRKM3, BRKM5 and BRKM6; NYSE: BAK; LATIBEX: XBRK) hereby informs its shareholders and the market in general that, on October 21, 2026, FFI Fund Ltd., FYI Ltd. and Olifant Fund Ltd. (the "Petitioning Creditors") filed an Involuntary Chapter 11 petition ("Chapter 11 Petition") in the United States Bankruptcy Court for the Southern District of New York against Braskem America Finance Company ("America Finance"), an indirect subsidiary of the Company whose sole purpose is to raise and manage funds in international markets to finance the operating activities of the Company and its subsidiaries. According to the documents filed, the Petitioning Creditors currently hold beneficial interest in the 7.125% Notes due 2041 issued by America Finance and guaranteed by the Company (the "2041 Notes"), in the principal amount of approximately US$272 million (approximately 47% of the aggregate outstanding principal amount of the 2041 Notes).

The Chapter 11 Petition relates to and affects only America Finance and its indebtedness, which consists exclusively of the 2041 Notes, in the principal amount of approximately US$589 million. The Company and its subsidiaries (including those subject to the ongoing extrajudicial reorganization in Brazil and to the Chapter 15 cases in the United States) are not listed as debtors in the Chapter 11 Petition.

For more information, contact Braskem’s Investor Relations Department by calling +55 (11) 3576-9531 or sending an e-mail to [email protected]

SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: October 21, 2026

FORWARD-LOOKING STATEMENTS

This Notice to the Market may contain forward-looking statements. These statements are not historical facts, but rather are based on the current view and estimates of the Company's management regarding future economic and other circumstances, industry conditions, financial performance and results, including any potential or projected impact regarding the geological event in Alagoas and related legal procedures on the Company's business, financial condition and operating results. The words “project,” “believe,” “estimate,” “expect,” “plan”, “objective” and other similar expressions, when referring to the Company, are used to identify forward-looking statements. Statements related to the possible outcome of legal and administrative proceedings, implementation of operational and financing strategies and investment plans, guidance on future operations, the objective of expanding its efforts to achieve the sustainable macro objectives disclosed by the Company, as well as factors or trends that affect the financial condition, liquidity or operating results of the Company are examples of forward-looking statements. Such statements reflect the current views of the Company's management and are subject to various risks and uncertainties, many of which are beyond the Company’s control. There is no guarantee that the events, trends or expected results will actually occur. The statements are based on various assumptions and factors, including, but not limited to, general economic and market conditions, industry conditions and operating factors, availability, development and financial access to new technologies. Any change in these assumptions or factors, including the projected impact from the joint venture and its development of technologies, from the geological event in Alagoas and related legal procedures and the unprecedented impact on businesses, employees, service providers, shareholders, investors and other stakeholders of the Company could cause effective results to differ significantly from current expectations. For a comprehensive description of the risks and other factors that could impact any forward-looking statements in this document, especially the factors discussed in the sections, see the reports filed with the Brazilian Securities and Exchange Commission (CVM). This Notice to the Market does not constitute any offer of securities for sale in Brazil. No securities may be offered or sold in Brazil without being registered or exempted from registration, and any public offer of securities carried out in Brazil must be made through a prospectus, which would be made available by Braskem and contain detailed information on Braskem and its management, as well as its financial statements.