OFF-ROAD VEHICLE MANUFACTURER S E A T P A N • Consolidate parts to reduce assembly time and lower manufacturing costs • Maintain performance while replacing metal seat pan with lightweight composite material • Aided consolidation of multiple metal parts and fasteners into a single injection molded component, lowering costs $100k year • Saved time and money using FEA validation to confirm real-world performance before building tooling • Created full-size 3D printed prototypes to test fit and function Complēt™ Long Glass Fiber Nylon Composite KEY REQUIREMENTS WHY AVIENT? AVIENT SOLUTION METAL REPLACEMENT + COST SAVINGS LEARN MORE Copyright © 2020, Avient Corporation.

Sync design with manufacturability: Learn how Avient Design Labs can help with your next project Our team of industrial designers and project engineers utilize a proprietary design process that enables you to get to market faster without unforeseen hurdles that cost you time and money. We’re working to find the ways in which 3D printing can take you to a new level of innovation.

TPEs can also incorporate a thermochromic additive that changes color depending on the temperature. In an infant feeding spoon, for example, the bowl of the spoon is made with a soft, flexible TPE that changes color when the food in the spoon is too hot for an infant to eat without burning his or her mouth. Soft, flexible TPEs can be easily overmolded onto hard substrates.

Sounds hard to believe, I know. PolyOne sponsors various voluntary retirement savings plans (RSP). Exhibit 31.1 CERTIFICATION I, Robert M.

The Company does not provide reconciliations of forward-looking non-GAAP financial measures, such as adjusted EPS and adjusted EBITDA, to the most comparable GAAP financial measures on a forward-looking basis because the Company is unable to provide a meaningful or accurate calculation or estimation of reconciling items and the information is not available without unreasonable effort. Factors that could cause actual results to differ materially from those implied by these forward-looking statements include, but are not limited to: disruptions, uncertainty or volatility in the credit markets that could adversely impact the availability of credit already arranged and the availability and cost of credit in the future; the effect on foreign operations of currency fluctuations, tariffs and other political, economic and regulatory risks; disruptions or inefficiencies in our supply chain, logistics, or operations; changes in laws and regulations in jurisdictions where we conduct business, including with respect to plastics and climate change; fluctuations in raw material prices, quality and supply, and in energy prices and supply; demand for our products and services; production outages or material costs associated with scheduled or unscheduled maintenance programs; unanticipated developments that could occur with respect to contingencies such as litigation and environmental matters; our ability to pay regular quarterly cash dividends and the amounts and timing of any future dividends; information systems failures and cyberattacks; our ability to service our indebtedness and restrictions on our current and future operations due to our indebtedness; amounts for cash and non-cash charges related to restructuring plans that may differ from original estimates, including because of timing changes associated with the underlying actions; and other factors affecting our business beyond our control, including without limitation, changes in the general economy, changes in interest rates, changes in the rate of inflation, geopolitical conflicts and any recessionary conditions.

Karibu switched from a local supplier to PolyOne to obtain an advanced TPE made without bisphenol A (BPA), phthalates, or heavy metals. The patented foldaway design enables easy storage without sacrificing a full-size tub for infants.

The non‐GAAP financial measures  i l d dj t d EPS i b f i t t t d i ti dinclude: adjusted EPS, earnings before interest, tax, depreciation and  amortization (EBITDA), adjusted EBITDA, net debt, Specialty platform operating  income, Specialty platform gross margin percentage, adjusted operating income,  return on invested capital, net debt/ EBITDA, and the exclusion of corporate p p charges in certain calculations.  EPS: $2.50 Assumptions • High single digit organic  revenue CAGR • Operating margins in mid range  of 2015 targets • No global recession• No global recession • No investment in incremental  PP&S capacity • Completion of 2‐3 midsize  accretive acquisitions • No divestitures  • Housing starts at 85% of 50 year  norm by 2015 R i f t bl b l 3X N t 2012 $ • Remain comfortably below 3X Net  Debt / EBITDA Page 13 Rev: $3.0B Adj.  Strong past performance demonstrates that our  strategy and execution are workinggy g • Megatrends align with our strengths • Innovation and services provide differentiation  and competitive advantage • Strong and proven management team driving  growth and performancegrowth and performance The New PolyOne: A Specialty Growth Company $2015 Target: $2.50 Adjusted EPS Page 16 Schedule I Reconciliation of Non-GAAP Financial Measures (Unaudited) (Dollars in millions, except per share data) Below is a reconciliation of non-GAAP financial measures to the most directly comparable measures calculated and presented in accordance with U.S.

IMPACT PROTECTION D E S I G N A N D M A T E R I A L S O L U T I O N S Avient Corporation 1 PROJECT KICK OFF B R I E F Application: Protective sports equipment Challenge: Provide functional material to protect against impact for chest protector Requirements: • Compact - reduce thickness and weight for improved comfort and functionality • Meet EN standards • EN1621-1 level 2 & EN1621-2 level 1 • Eliminate the use of foam and glue • Be waterproof and easy to clean • Sustainable • Easy to prototype & considers manufacturing efficiency Avient Corporation 2 VIBRATION DAMPING TECHNOLOGY (VDT) H O W D O E S I T W O R K ? Avient Corporation 3 Simplified Drop Test • 65g steel ball • Dropped from 305mm • Onto 3.175mm thickness flat samples Materials Tested • Standard TPE 30 Shore A • TPU alloy 60 Shore A • Damping TPE 32 Shore A VDT reduces bounce Avient Corporation 4 SIMULATION & CALIBRATION E N 1 6 2 1 - 1 L E V E L 2 Image courtesy of Airobag TV https://www.youtube.com/c/AirobagTV/videos Simulation of Impact A weight dropped onto protective element in contact with rigid substrate https://www.youtube.com/c/AirobagTV/videos Avient Corporation 5 SIMULATION & CALIBRATION E N 1 6 2 1 - 1 L E V E L 2 REFINING THE DESIGN D E S I G N A N D M A T E R I A L C O M B I N A T I O N Avient Corporation 6 • A number of different shapes and designs are created and simulated to determine which one works best • Refining to meet EN standard • VDT TPEs can help reach compliance with EN1621-1 level 2 and EN1621-2 level 1 • Optimum protection can be achieved by combining industrial design and engineering Avient Corporation 7 VALIDATION P R O T O T Y P I N G W I T H 3 D P R I N T I N G 3D Printing Validation -15% -10% -5% 0% 5% 10% Density Tensile Strength // Tear resistance // Rebound resilience 2mm 3D Printed VDT vs Injection Molded VDT can be 3D printed for concept evaluation early in the design process SUMMARY Avient Corporation 8 • Enabled a new, compact design with a customized VDT TPE formulation • Improved user comfort and functionality • Fulfilled EN standards • Reduced number of prototyping tools required • Reduced time spent in product development by 40 percent, enabling faster commercialization of product

Their cutting-edge HybridFabrication process enables highly efficient production of components, complete with mechanical, electrical, and plumbing systems, from their 252,000-square-foot manufacturing facility in Fairburn, Georgia.

I am pleased to report adjusted earnings per share increased 38% to $0.51 for the second quarter representing an all-time high for PolyOne," said president and chief executive officer Robert M. Factors that could cause actual results to differ materially from those implied by these forward-looking statements include, but are not limited to: our ability to realize anticipated savings and operational benefits from the realignment of assets, including the planned closure of certain manufacturing facilities; the timing of closings and shifts of production to new facilities related to asset realignments and any unforeseen disruptions of service or quality caused by such closings and/or production shifts; separation and severance amounts that differ from original estimates, amounts for non-cash charges related to asset write-offs and accelerated depreciation realignments of property, plant and equipment, that differ from original estimates; our ability to identify and evaluate acquisition targets and consummate acquisitions; the ability to successfully integrate acquired companies into our operations, retain the management teams of acquired companies and retain relationships with customers of acquired companies including without limitations Spartech Corporation; disruptions, uncertainty or volatility in the credit markets that could adversely impact the availability of credit already arranged and the availability and cost of credit in the future; the financial condition of our customers, including the ability of customers (especially those that may be highly leveraged and those with inadequate liquidity) to maintain their credit availability; the speed and extent of an economic recovery, including the recovery of the housing market; our ability to achieve new business gains; the effect on foreign operations of currency fluctuations, tariffs and other political, economic and regulatory risks; changes in polymer consumption growth rates where we conduct business; changes in global industry capacity or in the rate at which anticipated changes in industry capacity come online; fluctuations in raw material prices, quality and supply and in energy prices and supply; production outages or material costs associated with scheduled or unscheduled maintenance programs; unanticipated developments that could occur with respect to contingencies such as litigation and environmental matters; an inability to achieve or delays in achieving or achievement of less than the anticipated financial benefit from initiatives related to working capital reductions, cost reductions and employee productivity goals; an inability to raise or sustain prices for products or services; an inability to maintain appropriate relations with unions and employees; our ability to continue to pay cash dividends; the amount and timing of repurchases of our common shares, if any; and other factors affecting our business beyond our control, including, without limitation, changes in the general economy, changes in interest rates and changes in the rate of inflation.