Find answers about antioxidants, UV stabilizers, flame retardants, sourcing, documentation and more in our Plastic Additives FAQ.
Browse Plastic Additives FAQ →Answers about antioxidants, UV stabilizers, flame retardants and polymer additives for global buyers sourcing from China.
Suitability depends on the exact additive grade, polymer, use level, food type, temperature and destination market. A general technical grade should not automatically be described as food-contact compliant. Buyers should define the applicable regulation and request supporting declarations, substance identity, purity data and migration or extraction information where required. SUNCHEM can check available documentation for a specific product and supplier, but the finished-material manufacturer remains responsible for confirming compliance of the final formulation and article.
Yes. UV absorbers and HALS are frequently used together because they protect the polymer through different mechanisms. The UV absorber reduces the amount of damaging radiation entering the material, while the HALS suppresses radical reactions caused by photo-oxidation. The optimum ratio depends on polymer type, article thickness, pigment system, outdoor exposure and service-life target. Compatibility must also be checked because acidic additives, certain pigments and some flame-retardant systems can reduce HALS effectiveness.
Yes. COA, SDS and TDS are available for suitable products. Availability depends on the exact product, manufacturer, destination market and order stage. Additional declarations or test reports can be checked case by case after the buyer provides the product, application and regulatory requirements.
SUNCHEM supplies selected branded product lines and can evaluate custom specifications or alternative grades through qualified manufacturing partners. Feasibility depends on chemistry, volume, test methods, regulatory requirements and development cost. Custom products require technical review and sample approval before commercial supply.
Yes. SUNCHEM can support scheduled deliveries, annual-volume planning, specification management, quality documentation and supply-risk coordination for approved products. Commercial terms depend on forecast accuracy, product availability, payment terms and destination logistics.
Sample support is available for qualified evaluation projects, subject to product type, supplier policy, quantity, destination and shipping restrictions. Please provide the product or CAS number, target application, required quantity and courier details. Hazardous or restricted products may require additional review.
Migration and blooming usually occur when an additive has limited compatibility with the polymer, is used above its solubility limit, or is exposed to heat over time. Plate-out may also result from volatility, decomposition or interaction with lubricants and other formulation components. These problems can often be reduced by choosing a higher-molecular-weight or polymeric grade, lowering dosage, improving dispersion and checking the complete additive package. Processing temperature, cooling conditions and storage tests should be included in the evaluation.
Start with the polymer, processing temperature, residence time, expected service temperature and required regulatory status. PP and PE commonly use a hindered phenolic antioxidant together with a phosphite, while long-term heat ageing may require a thioester synergist. ABS and engineering plastics may need additives with higher thermal stability, lower volatility or better colour control. Other formulation components, including pigments, fillers, recycled resin and flame retardants, can change the required package. The final formulation should therefore be validated by melt-flow, colour, oven-ageing and application-specific testing.
Send the product name or CAS number, required specification, quantity, application, destination port, preferred Incoterm and documentation requirements. These details allow SUNCHEM to confirm a suitable supply source, packaging, lead time and freight basis before issuing a quotation.
Selection begins with the polymer and the required fire standard, such as a target UL 94 rating, limiting oxygen index or smoke requirement. Phosphorus-based systems are commonly considered for PC/ABS, epoxy and intumescent polyolefin applications; melamine-based products are used in selected polyamides; and mineral flame retardants such as aluminum hydroxide or magnesium hydroxide require relatively high loadings. Mechanical properties, processing temperature, moisture sensitivity, electrical performance and colour must be evaluated together with flame resistance. A material described as halogen-free should also be checked against the customer's specific regulatory or test definition.
There is no universal dosage. Antioxidants, UV stabilizers and flame retardants have very different use levels, and the effective concentration depends on the polymer, processing history, product thickness, exposure conditions and performance target. Supplier starting ranges can be used for initial trials, but the lowest-cost formulation is not always the lowest dosage because synergistic combinations may perform better. Final dosage should be established through laboratory compounding and tests such as colour, melt-flow retention, oven ageing, weathering and the required flammability standard.
Plastic additives are selected according to the degradation or processing problem that must be controlled. Primary antioxidants interrupt oxidation reactions, while secondary antioxidants decompose hydroperoxides formed during processing. UV absorbers absorb harmful ultraviolet energy, and hindered amine light stabilizers (HALS) slow photo-oxidation. Flame retardants reduce ignition or flame spread, while processing aids, lubricants, nucleating agents and other specialty additives improve manufacturing or end-use performance. The correct package depends on the polymer, processing temperature, service environment and regulatory requirements.
Please provide the polymer type and grade, processing method and maximum processing temperature, existing formulation, problem to be solved, target service life, exposure conditions, required test standard and destination-market compliance needs. For replacement projects, include the current additive name, dosage and performance gap. This information allows a supplier to compare suitable antioxidant, light-stabilizer, UV-absorber or flame-retardant options and reduces unnecessary trial work.
UV absorbers protect polymers by absorbing ultraviolet radiation and converting it into less harmful energy. HALS do not mainly absorb UV light; instead, they interrupt the photo-oxidation cycle and regenerate during the stabilization process. UV absorbers are especially useful where sufficient material thickness allows effective absorption, while HALS are highly effective in many outdoor plastics, coatings and thin articles. In demanding applications, a UV absorber and a HALS are often combined to improve colour retention, gloss and mechanical-property retention.
A plastic additive is the functional chemical itself, while a masterbatch is a concentrated mixture of additives or pigments dispersed in a carrier resin. Masterbatch can simplify dosing, reduce dust and improve dispersion, but the carrier and active-content level must be compatible with the final polymer and process.
Primary antioxidants, commonly hindered phenols, donate hydrogen to free radicals and help stop the oxidation chain reaction during processing and service life. Secondary antioxidants, such as phosphites and thioesters, decompose hydroperoxides before they generate additional radicals. They are often used together because the combination provides better processing stability and longer-term heat ageing protection than either type alone. Selection and dosage should be confirmed through formulation trials because polymer type, temperature and exposure conditions strongly affect performance.
SUNCHEM supplies antioxidants, light stabilizers, UV absorbers, flame retardants, optical brighteners, polymerization inhibitors and selected processing additives from qualified Chinese manufacturers. Core product lines include SUNNOX® antioxidants, SUNLIGHT® HALS, SUNSORB® UV absorbers and SUNFR® flame retardants. Availability, specification and documentation depend on the exact grade and intended application.
SUNCHEM can help screen Chinese supply options against the buyer's target specification, application and documentation requirements. Equivalent-grade evaluation should compare chemical identity, active content, physical properties, impurity profile and performance in the customer's formulation. A proposed alternative should not be treated as automatically interchangeable; sampling and application testing remain necessary before commercial approval.
Compare product identity, test methods, batch consistency, impurity profile, colour, volatility, packaging, documentation, production capacity and change-control practices. Also evaluate whether the supplier understands the application, can support samples and complaints, and can maintain supply during raw-material or logistics disruptions. A lower unit price may create higher total cost if quality variation causes production loss or reformulation.
Most plastic additives should be kept in unopened original packaging in a cool, dry, well-ventilated area away from heat, direct sunlight and moisture. Liquid phosphites and hygroscopic products may require tighter moisture control, while powders should be protected from contamination and caking. Shelf life depends on the exact grade, packaging and storage conditions, so the supplier's product-specific recommendation should be followed.
Buyers should review the current specification, recent COA, SDS, TDS, manufacturing origin, packaging, shelf life and any required regulatory declarations. For sensitive applications, confirm test methods, impurity limits, registration status, food-contact support, RoHS or REACH information and change-control procedures. Documents should match the exact grade and manufacturer rather than a generic product name.
Yellowing can result from excessive processing temperature, long residence time, an unsuitable antioxidant package, interactions with pigments or flame retardants, or contamination in recycled resin. It can often be reduced by improving temperature control, using a more hydrolytically stable phosphite, balancing primary and secondary antioxidants, and checking additive purity and compatibility. Comparative colour testing after extrusion and heat ageing is essential before changing the formulation.
Antioxidant 1010 is a high-molecular-weight hindered phenolic antioxidant with very low volatility and is widely used in polyolefins, engineering plastics, elastomers and adhesives. Antioxidant 1076 is also a hindered phenol, but it has a lower molecular weight and can offer easier incorporation in some polymer systems. Both provide long-term thermal oxidation protection. The preferred grade depends on polymer type, processing temperature, volatility requirements, colour target and the other stabilizers in the package.
DSTDP and DLTDP are thioester secondary antioxidants used mainly when long-term heat-ageing performance is important. They are commonly combined with hindered phenolic antioxidants in polyolefins, wire and cable compounds, automotive parts and other applications exposed to elevated temperatures. They are less focused on initial colour than phosphites and more focused on extended thermal stability. Compatibility, odour, extraction resistance and regulatory requirements should be checked for the final application.
Antioxidant 1010 is a primary antioxidant that interrupts free-radical oxidation, while Antioxidant 168 is a phosphite secondary antioxidant that decomposes hydroperoxides formed during processing. Using them together provides complementary protection against melt-processing degradation and longer-term ageing. The ratio should be optimized for the polymer, processing temperature, recycled content, colour requirements and expected service life.
A properly selected UV absorber normally has limited effect on visible transparency at recommended use levels, but some grades can contribute a slight initial colour or haze, especially at higher dosages or in very clear articles. Dispersion, additive purity, polymer compatibility and processing temperature all influence appearance. Transparent applications should be evaluated using haze, yellowness index and light-transmission measurements.
Both are benzotriazole UV absorbers used to protect polymers from ultraviolet degradation. Their differences in molecular structure affect absorption profile, volatility, thermal stability, compatibility and performance in specific polymers. UV 326 is commonly used in polyolefins, PVC, ABS and coatings, while UV 327 may be selected where lower volatility or different compatibility is required. Direct substitution should be confirmed through formulation and weathering tests.
The choice depends on polymer type, film thickness, required service life, processing temperature and the presence of pigments or fillers. Benzotriazole UV absorbers are widely used because of their broad UV absorption and thermal stability. Thin films often benefit from a combined package containing both a UV absorber and a HALS. Final selection should be validated through accelerated weathering and outdoor exposure testing.
Low-molecular-weight HALS generally disperse easily and can provide rapid stabilization, but they may be more prone to migration or extraction. High-molecular-weight or oligomeric HALS usually offer lower volatility, better extraction resistance and longer service life, which is valuable in films, fibres and outdoor articles. The best choice depends on polymer compatibility, article thickness, exposure conditions and contact with water, detergents or chemicals.
Agricultural film requires strong UV protection together with resistance to pesticides, sulfur-containing chemicals and repeated outdoor exposure. High-molecular-weight HALS are commonly considered for long service life, but the final grade must be compatible with the film resin, thickness and agrochemical environment. Sulfur-resistant or less basic HALS may be needed in demanding greenhouse applications. Validation should include accelerated weathering and chemical-exposure testing.
Conventional HALS contain basic amine functionality. Acidic pigments, halogenated flame-retardant systems, acidic fillers or certain catalyst residues can interact with or deactivate the HALS, reducing light-stabilization efficiency. In such formulations, formulators may consider less basic or NOR-type HALS, adjust the additive package, or use acid scavengers where appropriate. Compatibility testing is necessary because the interaction depends on the full formulation.
Yes. High flame-retardant loading can reduce impact strength, elongation, flow or surface quality, while some products may be moisture-sensitive or thermally unstable at the polymer processing temperature. Proper particle size, surface treatment, dispersing conditions and synergists can reduce these effects. Flame performance must be balanced with mechanical, electrical and processing requirements rather than optimized in isolation.
Both are halogen-free mineral flame retardants that release water endothermically and can reduce smoke. Aluminum hydroxide decomposes at a lower temperature and is commonly used in EVA, thermosets, cable compounds and construction materials processed below its decomposition range. Magnesium hydroxide has higher thermal stability and is more suitable for polymers processed at higher temperatures. Both often require relatively high loading, so particle size, surface treatment and mechanical-property retention are important.
Available halogen-free options may include phosphate esters such as BDP and RDP, ammonium polyphosphate, melamine-based systems, DOPO derivatives, aluminum hydroxide and magnesium hydroxide. Selection depends on the polymer, processing temperature, target fire rating, smoke requirements and mechanical-property limits. Regulatory status must be confirmed for the exact product and supply chain.
Provide the polymer and grade, target UL 94 rating, test thickness, processing temperature, colour, mechanical-property requirements, electrical requirements and any halogen-free or smoke restrictions. It is also important to identify fillers, pigments, glass fibre and other additives because they can change flame performance. A supplier can suggest a starting system, but the finished compound must be tested by the responsible manufacturer or an accredited laboratory.
DOPO is a reactive phosphorus-containing flame-retardant intermediate used in epoxy resins and other thermosetting systems, including selected electronic laminates, encapsulants and composite applications. It is often used to introduce phosphorus into the polymer structure, but formulation and curing performance must be validated in the final resin system.
TBBPA, or tetrabromobisphenol A, is a brominated flame retardant used mainly as a reactive component in epoxy resins for printed circuit board laminates and, in some applications, as an additive in polymers such as ABS. The suitable grade and use level depend on the resin system, target fire standard and destination-market requirements.
Reactive flame retardants chemically bond into the polymer or resin network during manufacture, which can reduce migration and improve permanence. Additive flame retardants are physically blended into the polymer and are generally easier to formulate across different materials. Reactive systems are common in selected epoxy, polyurethane and unsaturated polyester applications, while additive systems are widely used in thermoplastics. The choice affects processing, mechanical properties, recyclability and regulatory performance.
Yes. Excessive dosage may produce a bluish or greenish cast, uneven colour, fluorescence saturation or migration. The optimum level is often low and depends on the base resin, pigments, fillers and article thickness. Dosage should be established by colour measurement and visual comparison under relevant lighting.
Selection depends on polymer compatibility, processing temperature, colour target, migration resistance and required transparency. A brightener suitable for PVC may not be ideal for high-temperature engineering plastics. Comparative trials should evaluate dosage, whiteness, hue, thermal stability and long-term colour retention.
An optical brightener absorbs ultraviolet light and re-emits part of it as blue visible light, reducing the visual effect of yellowing and making white or light-coloured plastics appear brighter. It does not remove the underlying cause of degradation, so antioxidant and light-stabilizer packages may still be required.
Nucleating agents promote faster and more uniform crystallization in polypropylene. They can shorten moulding cycles and improve stiffness, dimensional stability or clarity depending on the grade. Performance depends on resin type, cooling conditions, dosage and dispersion.
Processing aids can improve melt flow, fusion, dispersion, surface finish, release or throughput. Their function depends on the polymer and process. They may reduce melt fracture in extrusion, improve PVC fusion, assist filler dispersion or lower equipment deposits. Selection must consider downstream properties and possible migration.
Internal lubricants reduce friction within the polymer melt and can improve flow, while external lubricants reduce adhesion between the polymer and metal processing surfaces. Many formulations require a balance of both. Excess lubricant can reduce fusion, printing, bonding or mechanical properties, so dosage should be optimized experimentally.
Yes. Inhibitors can be consumed by oxygen, radicals, contaminants, heat or light over time. Long storage, elevated temperature and poor circulation may create uneven inhibitor levels. Users should follow product-specific monitoring, temperature-control and replenishment procedures and should not rely only on the original loading concentration.
Selection starts with the monomer chemistry, process temperature, oxygen availability, storage duration and downstream polymerization method. Some inhibitors require dissolved oxygen to work effectively, while others are used for high-temperature processing or emergency protection. Removal or residual-inhibitor requirements must also be considered.
A polymerization inhibitor slows or prevents unwanted polymerization during manufacture, storage and transport of reactive monomers. It helps reduce heat generation, viscosity increase, gel formation and equipment fouling. The inhibitor type and concentration must match the monomer, oxygen level, storage temperature and expected holding time.
Yes. Recycled polymers often require restabilization because previous processing and service life have consumed part of the original additive package. Antioxidants, compatibilizers, odour-control products, chain extenders or light stabilizers may be considered. The correct package depends on contamination, degradation level and target application.
SUNCHEM supplies selected thiazole, sulfenamide, thiuram, dithiocarbamate and guanidine accelerators, including products such as MBT, MBTS, CBS, TBBS, TMTD and DPG. The correct accelerator or blend depends on elastomer type, cure rate, scorch safety, processing conditions and regulatory requirements.
Find answers about chemical products, applications, quality control, documentation and global supply solutions.
Answers about antioxidants, UV stabilizers, flame retardants and polymer additives.
Browse FAQs →Answers about solvents, resins, industrial raw materials and chemical sourcing.
Browse FAQs →Answers about APIs, intermediates, amino acids and quality requirements.
Browse FAQs →Answers about agrochemical intermediates and specialty chemicals.
Browse FAQs →A quick look at the questions global buyers ask us most. Browse the categories above for the full knowledge base.
SUNCHEM supplies specialty chemicals across several categories, including pharmaceutical and fine chemical intermediates, plastic and polymer additives, agrochemical intermediates, organic solvents, food additives, and water treatment chemicals, sourced through self-operated production lines and a network of selected Chinese manufacturers.
Our quality inspection team works with a long-term cooperation GLP laboratory to verify test results. If a customer's test results differ from the supplier's, we arrange independent third-party testing to confirm accuracy, authenticity and reliability before the order moves forward.
Yes. Depending on the product and supplier, we can provide TDS, SDS/MSDS, COA, product specifications and other export-related documentation to support your import and quality-check requirements.
Yes. Every supplier we work with goes through a qualification audit, site visit and sample testing before approval, and we continue to evaluate factories on criteria such as production standards, environmental protection facilities and laboratory capability.
Yes. We support customization across catalysts, pharmaceutical intermediates, plastic and resin additives, and specialized chemical reactions, working with manufacturers to match your specific formulation or process requirements.
We support buyers worldwide from our offices in Yangzhou, Hong Kong, Osaka and Seoul. Import and export requirements vary by destination, so our team confirms applicable documentation, packaging and compliance requirements for each shipment.
Our team reviews your intended application, processing method and target performance requirements, then helps you compare suitable products or grades from our manufacturer network before you commit to an order.
Yes. Many of our customer relationships are built on repeat sourcing and long-term supply arrangements, supported by consistent quality control, supplier management and logistics coordination on every order.
Common questions from global buyers about sourcing, quality and working with SUNCHEM.
SUNCHEM supplies specialty chemicals across several categories, including pharmaceutical and fine chemical intermediates, plastic and polymer additives, agrochemical intermediates, organic solvents, food additives, and water treatment chemicals, sourced through self-operated production lines and a network of selected Chinese manufacturers.
Our quality inspection team works with a long-term cooperation GLP laboratory to verify test results. If a customer's test results differ from the supplier's, we arrange independent third-party testing to confirm accuracy, authenticity and reliability before the order moves forward.
Yes. Depending on the product and supplier, we can provide TDS, SDS/MSDS, COA, product specifications and other export-related documentation to support your import and quality-check requirements.
Yes. Every supplier we work with goes through a qualification audit, site visit and sample testing before approval, and we continue to evaluate factories on criteria such as production standards, environmental protection facilities and laboratory capability.
Yes. We support customization across catalysts, pharmaceutical intermediates, plastic and resin additives, and specialized chemical reactions, working with manufacturers to match your specific formulation or process requirements.
We support buyers worldwide from our offices in Yangzhou, Hong Kong, Osaka and Seoul. Import and export requirements vary by destination, so our team confirms applicable documentation, packaging and compliance requirements for each shipment.
Our team reviews your intended application, processing method and target performance requirements, then helps you compare suitable products or grades from our manufacturer network before you commit to an order.
Yes. Many of our customer relationships are built on repeat sourcing and long-term supply arrangements, supported by consistent quality control, supplier management and logistics coordination on every order.
