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Plastics & Elastomers
The material selection platform
Plastics & Elastomers

UV Light Resistance

UV Light Resistance
  1. What is ultraviolet (UV) light?
  2. What is the effect of UV light on plastics?
  3. What plastics show good UV resistance?
  4. What prevents the damage of plastics by UV light?
  5. What test methods determine plastic material behavior in UV light?
  6. What are the values of UV resistance behavior of various polymers?

What is ultraviolet (UV) light?

Ultraviolet light is a part of the electromagnetic spectrum. It is at the higher end of energy compared to visible light. It is followed by X-rays and Gamma rays in terms of energy. UV energy absorbed by plastics can excite photons, which then create free radicals.

UV light is probably the most damaging environmental factor for plastics. Although to be fair to plastics, it attacks, to a greater or lesser extent, most other materials as well. All applications of plastics that are used outdoors are thus at risk. This includes roofing and window frames for vehicles. While many pure plastics cannot absorb UV radiation, the presence of catalyst residues and other impurities will often act as receptors, causing degradation.

Elecromagnetic Spectrum
The Electromagnetic Spectrum

What is the effect of UV light on plastics?

The UV light breaks down the chemical bonds in a polymer by photodegradation. This ultimately causes a change in appearance and deterioration in properties. It leads to discoloration. Primarily yellowing or whitening ('chalking') is most apparent. But, underneath, there is usually the beginning of a loss of physical properties. These include impact strength, tensile strength, and elongation. UV light can cause color change and degradation of physical properties, especially in:

  • Polyolefins
  • Polyvinyl chloride (PVC)
  • Polycarbonate (PC), and
  • Polyurethane (PU)

Hence, any attempt to design plastic parts without a clear understanding of the degradation mechanisms induced by the environment would result in a premature failure of the product.

Learn to Minimize the Discoloration of PVC Products »

What plastics show good UV resistance?

  1. Thermoplastics with Good UV Resistance — View All Products
  2. TPEs/TPVs with Good UV Resistance — View All Products
  3. Rubbers with Good UV Resistance — View All Products
  4. Thermosets with Good UV Resistance — View All Products

Note: UV radiation attacks all types of polymers. But a few polymers (acrylonitriles & methyl methacrylates) show better UV resistance than most.

What prevents the damage of plastics by UV light?

Plastics get damaged due to their oxidation caused by UV light. The counter-measures to prevent/terminate oxidation of plastics by UV light include:

  • coating,
  • introducing pigments that screen out the rays, or
  • neutralizing the UV energy within the compound and dissipating it.

Also, there exist many more technologies such as polymeric stabilizers, concentrates and masterbatches, fine particle technologies, etc. These help in preventing UV radiation from reaching the polymer. Thus, it helps to avoid damage. Some of the technologies are listed below.

Exploring screening pigments

  • Carbon black is the most effective screening pigment. However, its applications are limited to black-colored products.
  • Titanium dioxide is also used. But, it is expensive.
  • Calcium carbonate can also have a screening effect. But, usually at a high loading, it might impair mechanical properties.

Mechanism of UV absorbers

UV absorbers are receptive to UV radiation. But, they do not themselves degrade rapidly. They convert UV energy and dissipate it harmlessly as heat. They prevent the oxidation caused by UV radiation. However, they should not be confused with antioxidants, which are not UV deactivators as such.

Structure of Benzophenone and Benzotriazole
(A) Structure of Benzophenone; (B) Structure of Benzotriazole
Source: ResearchGate

Role of UV stabilizers and quenchers

  • Ultraviolet stabilizers work, unlike UV absorbers. They inhibit bond rupture by chemical means or dissipate the energy to lower levels that do not attack the bonds.
  • Quenchers reduce the UV energy by means of deactivating metal ions. In effect, they intercept the energy before it can break any molecular bonds. But, they work in a different way from absorbers.

Scavenging free radicals - HALS for enhanced polymer protection

Scavengers act by inhibiting the free radicals generated by UV light. Thus, stopping any further decomposition. The most important are hindered amine light stabilizers (HALS). They are efficient scavengers. They function by inhibiting the degradation of a polymer that has already formed free radicals.

HALS have the advantage that they bind additives to the polymer at the molecular level. This causes less antagonism towards other additives. They can be used with most polymers. Polymeric HALS offer:

  • Superior compatibility
  • Low volatility
  • Excellent resistance to extraction, and
  • Contribute to heat stability

A combination of two high molecular weight grades gives a good balance of properties for greenhouse film. Low density polyethylene (LDPE) film is mainly used in HALS.

Synergists with HALS

In conjunction with other light stabilizers, HALS can exhibit synergistic effects. These are being actively explored. For example, some cyanoacrylate-based UV absorbers offer particular benefits in:

What test methods determine plastic material behavior in UV light?

There exist several test methods to predict the behavior of plastic material to UV light. These test methods characterize material performance when subjected to specific and well-defined factors. But, it is also important to note that no one test can be employed to test completely the effects of UV light on any material.

  • ASTM D2565 — It determines the xenon-arc exposure of plastics intended for outdoor applications.

  • ASTM D4459 — It determines the xenon-arc exposure of plastics intended for indoor applications.

  • ASTM D4329 — It determines the fluorescent ultraviolet (UV) lamp apparatus exposure of plastics.

  • ASTM G154 — It operates fluorescent ultraviolet lamp apparatus for exposure to non-metallic materials.

  • ISO 4892 — It determines the methods of exposure to laboratory light sources. It is a four-part standard covering different light sources.
    • Part 1: General guidance
    • Part 2: Xenon-arc exposure
    • Part 3: Fluorescent UV exposure
    • Part 4: Carbon-arc exposure

What are the values of UV resistance behavior of various polymers?

Ratings in the table below are based on an overall qualitative assessment.

Click to find polymer you are looking for:
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Polymer Name Value
ABS - Acrylonitrile Butadiene Styrene
ABS Flame Retardant
Poor to Fair
ABS High Heat Poor
ABS High Impact Poor
ABS/PC Blend - Acrylonitrile Butadiene Styrene/Polycarbonate Blend
ABS/PC Blend 20% Glass Fiber Fair
ABS/PC Flame Retardant
ASA - Acrylonitrile Styrene Acrylate
ASA/PC Blend - Acrylonitrile Styrene Acrylate/Polycarbonate Blend
ASA/PC Flame Retardant Poor
ASA/PVC Blend - Acrylonitrile Styrene Acrylate/Polyvinyl Chloride Blend Good
CPVC - Chlorinated Polyvinyl Chloride
ECTFE - Ethylene Chlorotrifluoroethylene Good
ETFE - Ethylene Tetrafluoroethylene
EVA - Ethylene Vinyl Acetate
FEP - Fluorinated Ethylene Propylene
HDPE - High Density Polyethylene
HIPS - High Impact Polystyrene
HIPS Flame Retardant V0 Poor
Ionomer (Ethylene-Methyl Acrylate Copolymer)
LCP - Liquid Crystal Polymer
LCP Carbon Fiber-reinforced Good
LCP Glass Fiber-reinforced Good
LCP Mineral-filled Good
LDPE - Low Density Polyethylene
LLDPE - Linear Low Density Polyethylene
MABS - Transparent Acrylonitrile Butadiene Styrene Fair
PA 11 - (Polyamide 11) 30% Glass fiber reinforced
PA 11, Conductive Fair
PA 11, Flexible Fair
PA 11, Rigid Fair
PA 11 or 12 Fair
PA 12 (Polyamide 12), Conductive Fair
PA 12, Fiber-reinforced Fair
PA 12, Flexible Fair
PA 12, Glass Filled Fair
PA 12, Rigid Fair
PA 46 - Polyamide 46
PA 46, 30% Glass Fiber Fair
PA 6 - Polyamide 6
PA 6-10 - Polyamide 6-10
PA 66 - Polyamide 6-6
PA 66, 30% Glass Fiber Poor
PA 66, 30% Mineral filled Poor
PA 66, Impact Modified, 15-30% Glass Fiber Poor
PA 66, Impact Modified
Polyamide semi-aromatic Fair
PAI - Polyamide-Imide
PAI, 30% Glass Fiber Excellent
PARA (Polyarylamide), 30-60% glass fiber
PBT - Polybutylene Terephthalate
PBT, 30% Glass Fiber Fair
PC - Polycarbonate
PC (Polycarbonate) 20-40% Glass Fiber Fair
PC (Polycarbonate) 20-40% Glass Fiber, Flame Retardant Poor
PC - Polycarbonate, high heat Fair
PC/PBT Blend - Polycarbonate/Polybutylene Terephthalate Blend
PC/PBT blend, Glass Filled Fair
PCTFE - Polymonochlorotrifluoroethylene
PE - Polyethylene 30% Glass Fiber Fair
PEEK - Polyetheretherketone
PEEK 30% Carbon Fiber-reinforced Good
PEEK 30% Glass Fiber-reinforced Good
PEI - Polyetherimide
PEI, 30% Glass Fiber-reinforced Fair
PEI, Mineral Filled
PESU - Polyethersulfone
PESU 10-30% glass fiber Fair
PET - Polyethylene Terephthalate
PET, 30% Glass Fiber-reinforced Fair
PET, 30/35% Glass Fiber-reinforced, Impact Modified Poor
PETG - Polyethylene Terephthalate Glycol
PE-UHMW - Polyethylene -Ultra High Molecular Weight Fair
PFA - Perfluoroalkoxy
PI - Polyimide
PMMA - Polymethylmethacrylate/Acrylic
PMMA (Acrylic) High Heat Good
PMMA (Acrylic) Impact Modified
PMP - Polymethylpentene
PMP 30% Glass Fiber-reinforced Fair
PMP Mineral Filled Fair
POM - Polyoxymethylene (Acetal)
POM (Acetal) Impact Modified
POM (Acetal) Low Friction Poor
POM (Acetal) Mineral Filled
PP - Polypropylene
PP - Polypropylene 10-20% Glass Fiber Fair
PP, 10-40% Mineral Filled Fair
PP, 10-40% Talc Filled Fair
PP, 30-40% Glass Fiber-reinforced Fair
PP (Polypropylene) Copolymer
PP (Polypropylene) Homopolymer
PP, Impact Modified
PPE - Polyphenylene Ether
PPE, 30% Glass Fiber-reinforced Fair
PPE, Flame Retardant Poor
PPE, Impact Modified Poor
PPE, Mineral Filled Fair
PPS - Polyphenylene Sulfide
PPS, 20-30% Glass Fiber-reinforced Good
PPS, 40% Glass Fiber-reinforced Good
PPS, Conductive Good
PPS, Glass fiber & Mineral-filled Good
PPSU - Polyphenylene Sulfone
PS - Polystyrene Poor
PS - Polystyrene, 30% Glass Fiber Poor
PS (Polystyrene) Crystal Poor
PS, High Heat Poor
PSU - Polysulfone
PSU, 30% Glass finer-reinforced Fair
PSU Mineral Filled Fair
PTFE - Polytetrafluoroethylene
PTFE, 25% Glass Fiber-reinforced Good
PVC (Polyvinyl Chloride)
PVC (Polyvinyl Chloride), 20% Glass Fiber-reinforced  
PVC, Plasticized
PVC, Plasticized Filled Fair
PVC Rigid
PVDC - Polyvinylidene Chloride
PVDF - Polyvinylidene Fluoride
SAN - Styrene Acrylonitrile
SAN, 20% Glass Fiber-reinforced Poor
SMA - Styrene Maleic Anhydride Flame Retardant V0 Poor
SRP - Self-reinforced Polyphenylene Good
XLPE - Crosslinked Polyethylene

Disclaimer: all data and information obtained via the Polymer Selector including but not limited to material suitability, material properties, performances, characteristics and cost are given for information purpose only. Although the data and information contained in the Polymer Selector are believed to be accurate and correspond to the best of our knowledge, they are provided without implied warranty of any kind. Data and information contained in the Polymer Selector are intended for guidance in a polymer selection process and should not be considered as binding specifications. The determination of the suitability of this information for any particular use is solely the responsibility of the user. Before working with any material, users should contact material suppliers in order to receive specific, complete and detailed information about the material they are considering. Part of the data and information contained in the Polymer Selector are genericised based on commercial literature provided by polymer suppliers and other parts are coming from assessments of our experts.

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