Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2021 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36473 Trinseo PLC (Exact name of registrant as specified in its charter) Ireland N/A (State or other jurisdiction of incorporat ...

Fourth Quarter 2021 Financial Results & 2022 Outlook February 8, 2022 ™Trademark of Trinseo PLC or its affiliates Introductions & Disclosure Rules Introductions • Frank Bozich, President & CEO • David Stasse, Executive Vice President & CFO • Andy Myers, Director of Investor Relations Disclosure Rules Cautionary Note on Forward-Looking Statements.This presentation may contain forward-looking statements including, without limitation, statements concerning plans, objectives, goals, projections, forecasts, stra ...

Financial Data and Key Metrics Changes - In 2021, the company achieved record profitability with net income of $440 million and adjusted EBITDA of $729 million [8] - For the full year, net income from continuing operations was $280 million, and adjusted EBITDA was $729 million, with cash from operations of $453 million and free cash flow of $329 million [25][26] Business Line Data and Key Metrics Changes - The Engineered Materials segment's adjusted EBITDA was about $25 million lower than expected due to increased natural gas costs and higher raw materials and freight costs [24] - The company expects earnings in the first quarter of 2022 to be similar to the prior year, driven by continued demand strength and improved pricing actions [28] Market Data and Key Metrics Changes - The company noted robust demand for many products, particularly in ABS, polycarbonate, and polystyrene, despite challenges from external factors [19] - The automotive sector is experiencing constraints due to chip shortages, impacting overall demand [30] Company Strategy and Development Direction - The company is transforming into a specialty materials and sustainable solutions provider, with acquisitions aimed at enhancing product offerings and entering new markets [9][10] - The acquisition of Heathland B.V. aligns with the company's sustainability goals and aims to secure a steady supply of recycled feedstocks [12][13] Management's Comments on Operating Environment and Future Outlook - Management acknowledged challenges in 2021 due to external factors like weather events and COVID-19, but expressed confidence in overcoming these obstacles [16] - The company anticipates continued strong cash generation in 2022, with expected cash from operations of $530 million to $580 million [32] Other Important Information - The company plans to increase its quarterly dividend from $0.08 to $0.32 per share and has reinstated its share repurchase program [26] - The company is focusing on organic growth in sustainable products, with a significant increase in sales volume of recycled products [15] Q&A Session Summary Question: Timing and interest in the Styrenics divestiture - Management expects good interest from strategic buyers, regional players, and financial sponsors, with updates on timing to come in future quarters [36][37] Question: Buyback program expectations for 2022 - The buyback program will be opportunistic, with expectations for a similar amount to the $48 million buyback in Q4 2021 [38] Question: Sustainable margins in Engineered Materials - Management indicated that Q4 margins were impacted by external factors, but pricing actions taken should improve margins moving forward [41][44] Question: Heathland acquisition's role in recycling strategy - The acquisition is crucial for securing a steady stream of recycled feedstock, with expectations for significant growth in sustainable solutions by 2030 [55][57] Question: Capital expenditures for the new portfolio - Maintenance CapEx is estimated at $50 million to $60 million for the new portfolio, with additional spending on ERP implementation and manufacturing upgrades [58][60] Question: Future profitability of ABS and polycarbonate - Management expects slightly lower earnings in 2022 compared to 2021 due to the relaxation of supply chain constraints, but healthy end demand remains [70] Question: PMMA market dynamics - Management does not see PMMA as cyclical but rather as a solution-driven market with opportunities for growth through material substitution [74][80] Question: Sustainability targets post-Styrenics divestiture - The company aims to maintain its sustainability target of 30% of its portfolio being sustainably advantaged, even after the divestiture [96]

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36473 Trinseo PLC (Exact name of registrant as specified in its charter) (State or other jurisdiction of ...

Trinseo PLC (NYSE:TSE) Q3 2021 Earnings Conference Call November 8, 2021 10:00 AM ET Company Participants Andrew Myers - Director of Investor Relations Frank Bozich - President & Chief Executive Officer David Stasse - Executive Vice President & Chief Financial Officer Conference Call Participants Frank Mitsch - Fermium Research Laurence Alexander - Jefferies Hassan Ahmed - Alembic Global Advisors David Begleiter - Deutsche Bank Duffy Fischer - Barclays Eric Petrie - Citigroup Angel Castillo - Morgan Stanley ...

Financial Data and Key Metrics Changes - The company reported record net income and adjusted EBITDA for the second quarter of 2021, with expectations for net income from continuing operations between $344 million and $380 million and adjusted EBITDA of $750 million to $800 million for the year [14][18] - Free cash flow is projected to be between $275 million and $325 million, with capital spending expected to be $150 million, an increase due to the addition of the PMMA business and SAP S/4 upgrade project [20] Business Line Data and Key Metrics Changes - The Engineered Materials segment has seen an increase in product offerings due to the acquisition of Arkema's PMMA business, which is performing well despite industry challenges [8][10] - CASE products in latex binders have grown 23% year-to-date, indicating solid demand across various applications [14] Market Data and Key Metrics Changes - The company observed strong demand in products related to appliances, packaging, textiles, footwear, and building and construction, contributing to tight supply conditions and strong margins in styrene, polystyrene, ABS, and polycarbonate [14] - The Asian market for applications like hot tubs and swim spas is expected to grow at an average rate of 13% from 2020 to 2025 [11] Company Strategy and Development Direction - The company is focused on transforming into a specialty materials and sustainable solutions provider, with significant steps taken in 2021, including acquisitions and sustainability initiatives [7][13] - The acquisition of Aristech Surfaces is expected to broaden the product portfolio and enhance growth opportunities in Asia [10][12] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in navigating external challenges and anticipates a strong operating environment in derivative products well into 2022 [14][17] - The company expects to recover working capital used in the first half of the year as raw material prices normalize [17][20] Other Important Information - The company has set a sustainability goal of increasing the share of sustainably advantaged products to 40% by 2030, with progress reported in reducing greenhouse gases by 21% since 2017 [13] - The PMMA business is expected to contribute approximately $140 million in EBITDA on a prorated basis for the year [51] Q&A Session Summary Question: Clarification on 2021 guidance - Management confirmed that the improvement in guidance includes $80 million from the legacy business and the addition of PMMA, with no contribution from synthetic rubber [24][26] Question: Plans for free cash flow utilization - The company plans to prioritize transformation efforts, servicing debt, and reestablishing dividends over share buybacks [26][27] Question: Trends in polystyrene and ABS - Polystyrene demand is strong, contributing to the improved outlook, while ABS has seen robust demand despite raw material tightness [30][31] Question: Future EBITDA margins for Engineered Materials - Expected EBITDA margins for the Engineered Materials segment are projected to be above 20% going forward [35] Question: Insights on PMMA synergies - Initial synergies from the PMMA acquisition are expected from organizational efficiencies, with significant savings anticipated from ERP harmonization in the future [39][40] Question: Outlook for styrene and feedstocks - Management expects styrene feedstocks to normalize to a breakeven level over time, with little downside and potential upside in certain market conditions [41][42]

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36473 Trinseo S.A. (Exact name of registrant as specified in its charter) Luxembourg N/A (State or other juris ...

Q2 2021 Financial Performance - Net sales increased to $1.274 billion, a 138% increase year-over-year[9, 10] - Net income reached $133 million, compared to $26 million in Q2 2020[9] - Diluted EPS was $3.35, while Adjusted EPS was $3.70[12] - Adjusted EBITDA was $239 million, a significant increase from $17 million in Q2 2020[13] Segment Performance Highlights - Latex Binders net sales increased to $311 million, up 89% year-over-year, with volume up by 13%[15, 17] - Engineered Materials net sales increased to $181 million, a substantial 383% increase, including PMMA business contribution, volume increased 69%[20, 21] - Base Plastics net sales increased to $397 million, a 162% increase, volume increased 40%[24, 25] - Polystyrene net sales increased to $313 million, a 101% increase, volume decreased 12%[32, 31] - Feedstocks Adjusted EBITDA increased to $40 million from negative $4 million[36] Full Year 2021 Outlook - Net income from continuing operations is projected to be between $344 million and $380 million[41] - Adjusted EBITDA is expected to be between $750 million and $800 million[41] - Free Cash Flow is projected to be between $275 million and $325 million[43] Sustainability - Achieved a 21% reduction in GHG emissions and a 33% reduction in chemical emissions since 2017[6]

First Quarter 2021 Financial Results & Outlook May 6, 2021 Trinseo Confidential – For internal use only Introductions & Disclosure Rules Introductions • Frank Bozich, President & CEO • David Stasse, Executive Vice President & CFO • Andy Myers, Director of Investor Relations Disclosure Rules Cautionary Note on Forward-Looking Statements. This presentation contains forward-looking statements including, without limitation, statements concerning plans, objectives, goals, projections, strategies, future events o ...

Trinseo S.A. (NYSE:TSE) Q1 2021 Earnings Conference Call May 7, 2021 10:00 AM ET Company Participants Andrew Myers - Director, IR Frank Bozich - President, CEO & Director David Stasse - EVP & CFO Conference Call Participants Frank Mitsch - Fermium Research Hassan Ahmed - Alembic Global Advisors Matthew Blair - Tudor, Pickering, Holt & Co. Eric Petrie - Citigroup Angel Castillo - Morgan Stanley David Begleiter - Deutsche Bank Operator Good morning, ladies and gentlemen, and welcome to the Trinseo Firsts Quar ...