Quick Answer: Antioxidant 1010 and 168 are often combined because a hindered phenolic primary antioxidant controls free radicals while a phosphite secondary antioxidant decomposes hydroperoxides during polymer processing. The right ratio depends on resin, melt temperature, residence time, shear, color requirement, recycled content, and customer regulations. Qualification should measure processing color, torque or pressure stability, heat aging, extractables or migration where relevant, active content, particle condition, and lot consistency.
A blend that looks strong in a brochure can still fail when it is poorly dispersed, hydrolyzes in storage, or changes the color of a light polymer. This guide gives compounders and procurement teams a practical route for selecting, testing, and sourcing 1010/168 antioxidant systems for polyolefins, engineering plastics, masterbatch, films, molded parts, fibers, and recycled-polymer applications.
What Antioxidant 1010 and 168 Do Together
Antioxidant 1010 is a high-molecular-weight hindered phenolic antioxidant. It interrupts radical reactions that accelerate polymer oxidation during melt processing and long-term heat exposure. Antioxidant 168 is a phosphite processing stabilizer. It reacts with hydroperoxides before they decompose into additional radicals, helping protect the polymer during extrusion, compounding, and molding.
The two mechanisms are complementary. The phenol provides durable long-term protection, while the phosphite is especially useful during the high-temperature processing step. The balance between them affects initial color, odor, processing stability, long-term retention, and compatibility with the polymer and other additives.
Why the Ratio Must Be Tested
A fixed 1:1 ratio is not automatically correct. A high phosphite fraction may improve initial processing color but can be more sensitive to moisture and hydrolysis. A high 1010 fraction may support heat aging but may be slower to protect a severe melt history or may influence surface behavior in a low-polarity resin. The ratio should be selected from a controlled matrix around the expected commercial level.
| Trial direction | Potential benefit | Risk to check |
|---|---|---|
| More 1010 | Long-term heat stability and lower volatility | Initial color, dispersion, cost |
| More 168 | Processing color and peroxide control | Hydrolysis, odor, moisture sensitivity |
| Balanced blend | Synergy across processing and aging | Compatibility and lot consistency |
| Lower total dosage | Lower cost and less extractable material | Insufficient protection under severe heat |
Use equal polymer history, moisture, pigment, filler, screw settings, and sample conditioning for each blend. Test at least one approved control and retain all plaques, pellets, and test records.
Resin-Specific Selection
Polypropylene and polyethylene commonly use 1010/168 combinations, but the required level changes with melt temperature, shear, residence time, peroxide treatment, and recycled content. Engineering polymers such as ABS, polyamide, polyester, and polycarbonate may require additional attention to color, hydrolysis, residence time, and interactions with flame retardants or glass fiber.
For recycled polymers, measure the incoming oxidation history instead of assuming virgin-resin behavior. Odor, carbonyl growth, moisture, metal contamination, and previous stabilizer packages can change the response. The antioxidant blend should support a controlled reprocessing window, but it cannot replace sorting, drying, filtration, or removal of contaminants.
Dosage and Masterbatch Calculation
Report the dosage as active antioxidant in the final polymer and as concentrate let-down. If a masterbatch contains 20% total antioxidant and is dosed at 0.5%, the final polymer receives 0.10% total active additive. Record the 1010 and 168 contributions separately. This avoids a common purchasing error in which total concentrate loading is mistaken for active stabilizer content.
Screen low, nominal, and high total dosage, then vary the ratio around the nominal point. Measure melt color, torque, pressure, tensile retention, elongation, and oven-aging performance. Select the lowest level that meets the specification with enough margin for feeder and lot variation.
Processing Stability Tests
Run a controlled extrusion or torque-rheometer test at the actual melt temperature and residence time. Record start-up torque, steady torque, pressure, color at the first and last sample, and any die deposits. A stable antioxidant system should limit color drift and prevent rapid pressure increase caused by degradation or gel formation.
For films and fibers, inspect gels, black specks, die lines, odor, and surface deposits. For injection molding, record injection pressure, cycle time, part color, gloss, and short-shot behavior. For masterbatch, inspect pellet uniformity and downstream let-down. Use the same screw and screen pack for every candidate.
Color Retention and Yellowing
Measure L*, a*, b*, yellowness index, and color difference against the control. Use the same illuminant, observer, aperture, thickness, and conditioning. A blend may reduce yellowing while increasing haze or changing gloss. Visual approval under daylight and retail lighting should supplement instrumental data.
Track color after repeated heat history. A material that passes one extrusion may yellow after a second pass, pelletizing, or molding. For recycled content, compare first-pass and second-pass color retention and record the antioxidant replenishment strategy.
Thermal Aging and Lifetime
Heat aging tests should be selected around the customer’s expected service temperature. Expose plaques, films, or molded parts at controlled temperatures and intervals, then measure tensile retention, elongation, impact, color, mass change, and surface condition. Use an oven-aging curve rather than one end-point result when product life is important.
Processing stability and long-term aging are related but not identical. A blend can protect the first extrusion and still lose mechanical properties after extended heat. Conversely, a high long-term stabilizer level may not prevent an initial color spike if the phosphite is insufficient or hydrolyzed.
Moisture and Phosphite Hydrolysis
Antioxidant 168 is more sensitive to moisture and storage conditions than many phenolic antioxidants. Keep packaging sealed and dry. Record warehouse temperature, humidity, opening date, and partial-bag handling. Inspect for caking, discoloration, and damaged liners.
Run a moisture challenge when the polymer or customer process is sensitive. Compare fresh material with material stored under controlled humidity. Measure processing color, active-content indication, and any hydrolysis-related odor or residue. Do not assume that a dry COA guarantees performance after poor warehouse handling.
Compatibility with Pigments and Additives
Colorants, titanium dioxide, fillers, flame retardants, glass fiber, nucleating agents, lubricants, and processing aids can change antioxidant behavior. Some surfaces adsorb additives; others change moisture or local acidity. Evaluate the complete formulation rather than the antioxidant in neat polymer only.
In white and light-colored compounds, monitor initial b* and yellowing. In black compounds, check carbon black dispersion and gel count. In transparent parts, check haze and extractables. When the formulation changes, repeat at least the processing color and short heat-aging tests before releasing a new antioxidant lot.
Incoming Quality Control
- Verify identity, appearance, active-content indication and packaging.
- Check moisture, particle condition and caking.
- Review COA method, lot number, production date and release limits.
- Retain a sealed sample for comparison and complaints.
- Trend processing color and heat-aging performance by lot.
- Confirm SDS, TDS, regulatory and restricted-substance documents.
Powder appearance alone is not enough. A clean-looking antioxidant can still have a different active profile or processing response. Correlate incoming tests with production data and investigate unexplained drift early.
Supplier Qualification Questions
- What are the raw-material controls for 1010 and 168?
- Are the products manufactured and packed at the same site?
- How is moisture controlled for phosphite grades?
- What test method supports purity or active-content claims?
- How are particle size and agglomerates managed?
- What change-notification period is offered?
- Can the supplier provide samples, trial support and technical interpretation?
- What capacity, lead time, packaging and backup stock are available?
- How are complaints investigated and corrective actions documented?
Common Failure Modes
| Problem | Likely cause | Recommended action |
|---|---|---|
| High initial yellowing | Low 168, moisture, severe melt history | Check ratio, drying and residence time |
| Good processing color but poor aging | Insufficient 1010 or additive loss | Increase primary antioxidant or review compatibility |
| Specks or gels | Poor dispersion, contamination or degradation | Inspect powder, premix and screen pack |
| Odor after extrusion | Hydrolysis, contamination or overdosing | Run moisture challenge and review storage |
| Lot-to-lot color drift | Active variation or feeder error | Trend COA, dosage and feeder calibration |
Procurement and Total Cost
Compare cost per accepted kilogram of polymer, not only price per kilogram of antioxidant. Include dosage, masterbatch conversion, scrap, screen changes, die cleaning, heat-aging failures, customer claims, and inventory carrying cost. A consistent premium grade may be less expensive than a low-priced material that causes color correction or rework.
Specify packaging, shelf life, lead time, minimum order, delivery terms, change notice, and claim procedure in the RFQ. Ask whether the quoted grade matches the trial sample and whether the supplier can maintain the same manufacturing site and test method.
E-E-A-T, GEO and Inquiry Guidance
Technical buyers need direct answers: what does 1010 do, what does 168 do, how is the ratio selected, how is moisture controlled, which tests prove heat stability, and what documents accompany the lot? A strong technical page answers these questions with methods, limits, examples, and a clear inquiry path. Consistent terminology across product pages, TDS files, COAs, and quotations also helps search systems connect the information.
Hengyi Technology supports antioxidant sample selection, blend-ratio trials, polymer processing evaluation, technical documentation, and commercial supply. Review the product portfolio or contact our team with your resin, processing temperature, color target, aging requirement, annual demand, and destination market.
Frequently Asked Questions
Why combine Antioxidant 1010 and 168?
The primary phenolic and secondary phosphite mechanisms complement each other during processing and long-term heat exposure.
Is a 1:1 ratio always best?
No. The optimum ratio depends on resin, process severity, moisture, color requirement, recycled content, and customer regulations.
How should phosphite moisture sensitivity be controlled?
Use sealed packaging, dry storage, controlled opening, and a moisture challenge that reflects the real warehouse and process.
What is the most useful processing test?
Use the actual resin and formulation in a controlled extrusion or torque test, then measure color, pressure, torque, deposits and mechanical retention.
What should be included in an RFQ?
State resin, temperature, residence time, dosage range, ratio, color limit, aging target, packaging, annual quantity, documents and change-control expectations.
Conclusion and Inquiry CTA
Antioxidant 1010 and 168 should be qualified as a system rather than purchased as isolated powders. A controlled ratio study, processing-color test, moisture review, heat-aging program, incoming QC plan, and supplier audit create a defensible approval. The goal is stable processing, color retention, mechanical life, and repeatable supply.
Send Hengyi Technology your resin, formulation, melt temperature, residence time, target ratio, test method, annual volume, and delivery requirement. We can coordinate samples, interpret trials, and prepare a quotation for a reliable antioxidant program.
Designing a Ratio Matrix
Build the first trial around the current commercial dosage and ratio. For example, keep total antioxidant constant while comparing primary-to-secondary ratios on both sides of the control. Then run a second matrix that changes total dosage at the best ratio. This separates ratio effects from total-loading effects and prevents a misleading conclusion caused by two variables moving at once.
For every trial, record resin lot, moisture, pigment, filler, additive lot, premix order, feeder type, screw speed, melt temperature, pressure, residence time and cooling. Take samples at start-up, steady state and end-of-run. Retain enough material for re-testing after the initial color and mechanical results are reviewed.
Compounding and Premix Practice
Antioxidants can segregate when particle size, density, or shape differs from the resin and other powders. Use a controlled premix and avoid long storage of an unbound dry blend. Check whether a liquid carrier, wax, or masterbatch improves feeding without changing the final formulation. In a twin-screw line, evaluate the feed location and the distance available for melting and dispersion.
Inspect the hopper, gravimetric feeder, magnets, screen changer and die after the trial. Record dust, bridging, lumps and deposits. A small amount of contamination can affect a light-colored compound disproportionately. Clean and document the line before comparing a second supplier.
Mechanical Property Retention
Color alone cannot prove antioxidant performance. Measure tensile strength, elongation, impact, flexural strength or melt-flow change before and after thermal aging, depending on the product. For fibers, check tenacity, elongation and spin-finish behavior. For films, include dart impact, tear, seal strength and coefficient of friction when relevant.
Use a control compound and test at multiple aging intervals. A blend that maintains color but loses elongation may be protecting appearance without preserving molecular weight. Conversely, a small color change with good mechanical retention may be acceptable in an opaque product. Set the release criterion with the customer’s actual priority.
Reprocessing and Circular-Polymer Trials
Reprocessing exposes polymers to repeated heat, shear and oxygen. Run one-pass, two-pass and three-pass trials when recycled content or internal scrap is important. Measure melt flow, carbonyl growth where available, color, odor, black specks and mechanical retention. Do not assume that adding more antioxidant after every pass is always optimal; excessive dosage can affect odor, migration or processing.
Measure the starting stabilizer history of recycled feedstock whenever possible. Mixed sources may contain different phenols, phosphites, acids, metals and pigments. A robust qualification includes a realistic blend of incoming materials and a defined correction strategy for the next production cycle.
Migration and Regulatory Review
For food packaging, medical articles, toys, drinking-water components, and other regulated applications, review the complete formulation against the destination market. Ask for the supplier’s regulatory statement, residual limits, restricted-substance declaration, and change-control policy. The neat antioxidant document is not automatically a compliance statement for the finished polymer.
Run an application-specific migration or extractables screen when required. Check odor, taste, surface blooming and contact transfer after heat aging. Keep sample preparation and extraction conditions in the report so a customer can understand what was tested and what remains outside the scope.
Analytical Verification
Use appropriate analytical tools to verify identity and lot consistency. HPLC, FTIR, DSC, TGA, moisture analysis, microscopy and color measurement each provide different information. A practical incoming plan may use identity and appearance for every lot, moisture and active-content checks at a defined frequency, and a full performance trial for new suppliers or changes.
Compare the supplier COA with independent results on retained samples. If the methods differ, establish a correlation rather than treating a numerical difference as a failure. Trend results over time; slow movement in active content or particle condition can be more important than one result inside the specification.
Packaging, Storage and Shelf Life
Keep antioxidant 168 and blend products in sealed moisture-barrier packaging away from heat, water and direct sunlight. Store on pallets, protect liners from puncture, and use first-in-first-out rotation. Once a bag is opened, reseal it and record the opening date. Avoid returning exposed powder to an unopened lot.
Request shelf-life data and recommended storage conditions. If a shipment experiences high humidity or a long port delay, perform a moisture and processing-color check before use. Warehouse controls are part of the qualification system and should be audited together with the supplier.
Supplier Change Management
Require advance notification for changes to phenol or phosphite raw materials, stabilizer source, synthesis route, purification, particle-size classification, packaging site, laboratory method, or manufacturing location. Define which changes require a new sample, a lab check, a production trial, or customer notification.
Keep an approved sample and a written change record. When a supplier proposes a substitution, compare it with the original under equal processing and aging conditions. Do not approve a change solely because the chemical name and nominal purity look the same; morphology, residuals and moisture response may differ.
Commercial Scorecard
| Category | Evidence | Decision question |
|---|---|---|
| Processing | Torque, pressure, color and deposits | Does the blend protect the actual melt history? |
| Durability | Heat-aging mechanics and color | Does it preserve the customer’s service life? |
| Cleanliness | Specks, gels, filter and die inspection | Is the material consistently clean? |
| Compliance | SDS, TDS, COA and declarations | Can the grade be used in the intended market? |
| Supply | Capacity, lead time and change policy | Can the supplier maintain the approved result? |
| Economics | Cost per accepted kg and scrap | Is the delivered cost competitive at scale? |
Practical RFQ Template
- Polymer family and grade
- Virgin, recycled or mixed feedstock percentage
- Melt temperature, residence time and screw type
- Current 1010/168 ratio and total dosage
- Target processing color and heat-aging limit
- Mechanical properties to retain
- Moisture, particle and packaging requirements
- Regulatory market and end use
- Annual volume, shipment size and destination
- Required COA, SDS, TDS, samples and change notification
A complete RFQ allows a supplier to recommend a grade and trial plan instead of sending a generic antioxidant sample. It also makes offers comparable across price, technical evidence, and supply risk.
Plant Audit and Training
Train operators on dry storage, premix order, feeder calibration, sample labeling, screen inspection and spill control. Use a batch record that captures antioxidant lots, actual weights, processing settings, color results and disposition. Review the record whenever a lot is outside trend.
During a supplier audit, review calibration records, retained samples, nonconformance investigations, cleaning controls, packaging inspection and change notices. The objective is to verify that the approved ratio and performance can be reproduced, not simply to collect a certificate.
Quick Decision Rules
Approve a blend when it meets the critical processing-color, thermal-aging, mechanical-retention, moisture, compliance, and supply requirements at the selected ratio. If one critical test is incomplete, classify the material as trial-only. Use a documented risk ranking for noncritical deviations and define the owner and due date for every open action.
After approval, trend each lot against the control. Requalify after a source, site, process, packaging, or test-method change, after a long supply interruption, or when plant performance moves outside the control limits. This keeps the antioxidant program current and protects customer confidence.
Interpreting Unexpected Results
If processing color improves but heat-aging retention does not, review 1010 level, molecular weight, additive loss, and the severity of the aging test. If aging improves but initial color worsens, check 168 moisture, premix quality, residence time and the ratio. If both color and mechanics vary by lot, compare active content, particle condition, feeder accuracy, resin moisture and line cleanliness before changing the formula.
Use a root-cause tree rather than adjusting dosage immediately. Confirm the measurement system, check the control compound, inspect the screen pack, and compare retained powders. This avoids over-correcting a stable antioxidant system because of an instrument or sampling error.
Customer Communication and Technical Evidence
When quoting an antioxidant, provide a concise technical summary: mechanism, recommended screening range, storage conditions, documents, and the tests used for approval. State clearly which values are typical and which are guaranteed. Customers appreciate a supplier who explains uncertainty and proposes a practical trial rather than making an unsupported performance promise.
Keep application notes, COAs, trial photos, color charts, and complaint records linked to the product lot. This evidence supports E-E-A-T, improves AI-search retrieval, and helps the sales team answer technical questions consistently. It also shortens the path from first inquiry to a commercial sample.
Final Approval Summary
The best Antioxidant 1010 and 168 program is a controlled system: the ratio is chosen from a matrix, the dosage is calculated on active content, the process is tested at real temperature and residence time, and long-term durability is verified by heat aging and mechanical retention. Incoming QC, dry storage, change control and lot trending complete the qualification loop.
Hengyi Technology can help you compare 1010/168 grades, arrange samples, evaluate processing and aging data, and coordinate reliable supply. Send your resin, current ratio, melt history, target color, aging requirement, annual demand, and destination market for a focused recommendation and quotation.
Ongoing Performance Review
Review antioxidant performance with production, quality and purchasing at least quarterly. Compare lot chemistry, processing color, melt-flow change, mechanical retention, warehouse conditions, customer feedback and delivered cost. A small drift detected early is easier to correct than a failed customer shipment.
Use the same control material and test settings for each review. If a new polymer grade, pigment package, filler, or recycled source is introduced, record it as a formulation change and repeat the relevant processing and aging checks. This avoids treating a new formulation as if it were the previously approved one.
Business Continuity Planning
Qualify a backup lot or second source where the antioxidant is critical to production. Compare backup material on the same ratio, resin, screw, temperature and aging test. Keep a defined safety stock and a transition plan. A technically equivalent grade is only useful if it can be delivered when the main source is interrupted.
Document emergency contacts, lead times, shipment options and approval authority. Include the change-notification requirement in the purchase contract so an urgent substitution does not bypass technical review.
Closing Checklist
- Ratio and active dosage are documented.
- Processing color and pressure are within limits.
- Heat-aging and mechanical retention pass.
- Moisture and storage controls are verified.
- COA, SDS, TDS and regulatory files are current.
- Supplier change control and backup supply are approved.
This checklist gives engineering, quality, procurement, and sales one shared record for future orders and customer inquiries.
Keep the approved report with the product master and update it after each significant process or source change. This protects repeatability, customer confidence, and inquiry conversion.
For every shipment, retain a sample, record the receiving inspection, and link the lot to the production campaign. This makes root-cause analysis faster and gives the supplier clear evidence when a deviation is reported.
Clear records turn routine antioxidant purchasing into a controlled technical program with measurable outcomes.
Use these records during supplier reviews and annual contract renewal.
These records also support customer audits, technical reviews, supplier scorecards, and long-term consistency across production campaigns.
How to Qualify Antioxidant 1010 and 168 for Polymer Processing
When purchasing Antioxidant 1010 and 168 for polymer processing, compare the ratio, active dosage, resin history, moisture and actual melt conditions rather than relying on a generic blend name.
Antioxidant 1010 and 168 for polymer processing should be approved with a control compound, processing color data, heat-aging evidence, and a documented supplier change policy.
For recycled resin, Antioxidant 1010 and 168 for polymer processing must be tested against the incoming oxidation history, moisture, metals, pigments and previous stabilizer packages.
During scale-up, trend Antioxidant 1010 and 168 for polymer processing by lot, dosage, color, melt flow and mechanical retention so drift is visible before a customer complaint.
Hengyi can support Antioxidant 1010 and 168 for polymer processing with samples, ratio trials, technical documents, and commercial supply planning.
