Automotive Polymer Additives: Weathering, VOC and Flame-Retardancy Solutions

The automobile is one of the most demanding applications of polymer materials in the world. A single vehicle contains over 30,000components, among which polypropylene (PP), TPO, PC, PVC, TPU, polyester and rubber are extensively used; and a vehicle must retain its appearance and performance across -40 degC to +85 degC temperature swings, several hours of direct sunlight per day, rain, snow, salt spray, and a service life of over ten years. This means the stabilizer for automotive use is not 'one additive,' but a coordinated system designed by location, by resin, and by failure mode.

Since 1991, Tiangang has focused on polymer additives and built a complete portfolio across four major categories - light stabilizers, UV absorbers, antioxidants and flame retardants - and offers the following distinctive products for the automotive industry: T-78 light-stabilizer pack for automotive modification,FR-810A polymeric halogen-free flame retardant,XT-8 high-molecular-weight NOR light stabilizer among other specialty products. This article is organized into five topics addressing the material issues of greatest concern to the automotive industry, the applicable standards, and Tiangang's corresponding solutions.

This topic is divided into five themes

For easy reference on demand, the five sub-topics below correspond to the five core problem categories of automotive materials. Click a card to enter.

1. Exterior parts: the first line of defense against photo-oxidative aging

Bumpers, grilles, mirrors, spoilers - how PP/TPO withstand UV, baking and gravel impact. Includes a phased stabilization scheme and dosage levels.

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2. Interior and cockpit: compliance issues of VOC, odor and fogging

Dashboard, door panels, seats, steering wheel - striking a balance among weather resistance, low VOC (VDA 278), low fogging and flame retardancy.

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3. Wiring, electrical and flame retardancy: the hard requirement of halogen-free, low-smoke

High-voltage harness at 1500V, charging cables, battery-pack enclosure - beyond GB 38031 and FMVSS 302, how to achieve both flame retardancy and aging resistance.

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4. New-energy-specific materials: battery pack, roof and charging port

GB 38031-2025 thermal-propagation regulation, LGF-PP battery tray, rooftop PV film, charging gun - new additive demands brought by new standards.

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5. Quick-selection table and product matrix

Look up additive formulations by location x material x failure mode; an overview of Tiangang's full range of automotive-compatible products and how to engage.

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I. The real mechanism of automotive material aging

In the lab, the strength loss of PP sheet under sunlight is visible to the eye; but in an OEM's failure analysis, the problem is often more complex -it is never a single factor, but the superposition of multiple factors. Understanding this is the prerequisite for selecting the right additive system.

1.1 Exterior parts: why PP is particularly difficult to handle

Every repeat unit on the PP main chain carries atertiary C-H bond, which is highly prone to hydrogen abstraction under UV or thermal excitation, initiating an autocatalytic 'hydroperoxide -> radical' chain reaction. The insidious part of this mechanism is that it isautocatalytic: once the chain reaction starts, the material can jump from 'slight discoloration' to 'chalking, loss of gloss + sharp drop in impact strength' in a very short time.

Measured data illustrate the point: under strong sunlight,unstabilized PP can lose 70% of its strength within days; whereas a similar formulation treated with a complete stabilization system can have its outdoor life extended to several years. The difference is not in 'what was added,' but in 'whether the system is correctly built.'

1.2 Interior parts: beyond weather resistance, there are VOC, odor and fogging

The interior is another battleground. The dashboard temperature under summer sun exposure can reach 80-100 degC80–100℃, while semi-volatile substances inside the cabin (plasticizers in soft PVC, white oil in TPE, residual DMF in PU synthetic leather) volatilize at high temperature and re-condense on the windshield, formingfogging deposits- which is both a safety risk and a core focus of OEM VOC regulations.

1.3 Electrical and new energy: the superimposed requirements of halogen-free flame retardancy and long life

The operating voltage of high-voltage wiring harnesses has reached AC 1000V / DC 1500VAC 1000V / DC 1500V, with a long-term operating temperature of 125-150 degC; the battery-pack enclosure must simultaneously satisfyhalogen-free flame retardancy + long-term thermal stability + outdoor weather resistance. When these three are combined, the common simple 'antioxidant + flame retardant' combination hinders itself - especiallybecause acidic substances released by halogen-containing or phosphorus-containing flame-retardant systems neutralize conventional basic HALS, causing premature deactivation. This is precisely why XT-8 (N-OR structure, does not react with acids) and FR-810A (polymeric NOR halogen-free flame retardant) exist.

II. The standard thresholds of the automotive industry: which gates must materials pass first

Formula review for automotive materials is, in essence, a point-by-point response to the following sets of standards. The table below lists the most frequently cited and most illustrative parts.

III. Tiangang's capability composition for the automotive industry

Since its founding in 1991, Tiangang has focused on polymer additives for over thirty years, forminga complete matrix with all four categories covered and in-house intermediate supply capability, and has built three major production bases in Daxing (Beijing), Gu'an (Hebei) and Cangzhou (Hebei), with a combined annual capacity of about 30,000 tonnes, and established Tiangang Chemicals Europe B.V. (Brussels, Belgium) in Europe. The significance of this structure for automotive customers is:from single-product procurement to turnkey solution delivery, without having to piece together formulations across multiple suppliers.

3.1 How the four major categories jointly address automotive aging

3.2 Four distinctive products

IV. What Tiangang can provide

• Location-based overall formulation recommendations- not a single-additive recommendation, but a complete combination and dosage range of light stabilizer + antioxidant + UV absorber (with flame retardant when necessary) for specific parts (bumper / dashboard / wiring harness / battery-pack enclosure...).
• Aging tests and formulation-screening support- test assistance for customer formulations on xenon aging (SAE J2412 / J2527 / ISO 4892-2), thermal-oxidative aging, color difference, fogging, etc., helping lock in the system at the prototyping stage.
• In-house intermediates and supply stability- key HALS intermediates (TAA,TMP,TAD etc.) are self-produced, favoring batch consistency and controllable lead times, which is critical in automotive supply chains requiring 4M change management.
• Solutions in functional masterbatch form- such as MB0607-1 light-stabilization functional masterbatches, MB6250PP20 / MB6251PP20 anti-UV functional masterbatches, suitable for downstream processing scenarios where direct powder addition is inconvenient.
• European service window- Tiangang Chemicals Europe B.V. (Brussels, Belgium), providing local technical liaison for European OEMs and tier-1 suppliers.

V. How to get started

We suggest providing the following information at first contact, so we can give more targeted recommendations:1. Part name and location (exterior / interior / electrical / structural); 2. Resin type and grade; 3. Currently observed failure phenomena (discoloration, chalking, gloss loss, embrittlement, blooming, fogging...); 4. Standards or OEM specs to pass; 5. Additives and dosages already used in the existing formulation.

If you are not sure which product to start with, you can also first look at 5. Quick-selection table and product matrix, look up the recommended system by location; or contact our technical team directly.