DB77 Non-Yellowing Plasticizer for Construction and Automotive MS Sealants
DOBO Technical R&D TeamUpdated 9 on Nov 2026Oct 26, 2026
DB77 for construction and automotive sealant systems: causes of sealant yellowing, compatibility with common resins and calcium carbonate fillers, and methods to verify appearance stability through weathering and color measurement.
DB77 Non-Yellowing Plasticizer for Construction and Automotive MS Sealants
What causes a sealant to yellow over time?Yellowing in plasticized sealants typically results from plasticizer oxidation or reactions between the additive package and light, heat, or atmospheric pollutants. A yellowing-resistant plasticizer maintains joint appearance stability over time. DB77 is designed for construction and automotive sealant systems, offering excellent compatibility with common resins and consistent anti-yellowing performance throughout its service life. It is ideal for formulations requiring superior weatherability and long-term aesthetic stability.
Yellowing is an appearance defect indicating a chemical issue.
A sealant joint that is white when installed but turns beige after a year indicates more than just a cosmetic issue. In most cases, the color change reflects the same oxidation process that degrades the sealant's mechanical properties. On automotive parts, it can also signal a risk of fogging or staining on adjacent surfaces.
| Cause of color change | Mechanism | Formulation response |
|---|---|---|
| Plasticizer oxidation | Light and heat degrade the molecule, producing colored products. | Use an oxidation-resistant plasticizer |
| Residual aromatic structure | Absorbs ultraviolet energy and forms conjugated color bodies. | Prefer a non-aromatic ester structure |
| Additive interaction | Stabilizer or biocide reacting with the plasticizer | Recheck the entire additive package |
| Surface contamination | Atmospheric pollutants and dirt accumulation | Consider surface energy and cleaning. |
| Production heat history | Over-mixing | Control temperature profile |
DB77 is formulated based on the first two rows of that table. Its compatibility with common resins keeps it in the compound rather than at the surface, and its anti-yellowing performance ensures long-term appearance retention throughout the product's service life.
Compatibility with resins used in MS sealant systems
MS sealant systems are based on silyl-modified polymer chemistry. The plasticizer must remain compatible with the polymer, calcium carbonate fillers, and adhesion promoters that enable bonding to concrete, metal, or painted panels. Incompatibility manifests in three ways: plasticizer exudation to the surface, loss of adhesion at the joint edge, and reduced elongation after aging.
| Compatibility question | Verification checklist | Practical implications |
|---|---|---|
| With the base polymer | Uniform blend, no surface film | Appearance stability and elongation retention |
| Filled with calcium carbonate | No thickening or phase separation | Storage Stability and Extrusion Behavior |
| With adhesion promoters | No loss in bond strength | Joint durability on intended substrates |
| With stabilizers and pigments | No color shift after heat aging | Color consistency of the finished joint |
| Over time and with exposure to weather | No bloom or chalking | Long-lasting appearance |
Construction and automotive requirements
These two markets overlap but use different languages. Construction sealants are evaluated based on movement capability, adhesion to masonry, and weatherability over years of UV exposure and rain. Automotive sealants are assessed for bond durability on painted and coated surfaces, non-staining of adjacent trim, and performance across the vehicle's temperature range. Interior applications also include appearance specifications related to fogging and odor.
| Application | Key requirement | Why Plasticizers Matter |
|---|---|---|
| Building facade joints | Weather resistance and color stability | Plasticizer oxidation causes visible yellowing |
| Window and panel sealing | Prioritize connection over motion | Compatibility affects joint durability |
| Automotive body and trim sealing | Non-staining and long-lasting bond | Migration may stain paint and trim |
| Interior automotive sealing | Low fogging and low odor | Volatile Content and Aging Behavior |
Testing visual stability the right way
Appearance claims cannot be verified by short oven exposure alone. A meaningful assessment of non-yellowing performance requires combining accelerated weathering with quantitative color measurement, comparing the candidate against the current formulation under identical conditions.
| Test approach | What it shows | Note |
|---|---|---|
| Accelerated weathering (UV and moisture cycling) | Color development speed | Use the same cycle for each sample |
| Color measurement (color difference value) | Magnitude of change, not just a visual judgment | Report the numerical change |
| Heat Aging | Production heat history sensitivity | Related to processing control |
| Outdoor exposure | Real service behavior | Long duration; useful as a final check |
| Mechanical tests after aging | Do appearance and performance go hand in hand? | Elongation and adhesion retention |
Frequently asked questions
Does DB77 prevent yellowing entirely?No plasticizer can guarantee this. DB77 is engineered for long-term anti-yellowing stability, but the final outcome depends on the complete formulation, filler package, and exposure conditions. Appearance must be verified through weathering tests and color measurement.
Is DB77 suitable for both construction and automotive sealants?Designed for construction and automotive sealant systems, with excellent compatibility with common resins. Both markets should verify their specific requirements, particularly interior automotive fogging and odor limits.
Can it be used with other sealant chemistries?Compatibility must be confirmed for each system. For MS and related sealant systems that include a plasticizer in the formulation, DB77 is the recommended application.
Will this change the extrusion behavior?Compatibility with fillers is one factor in maintaining stable viscosity, but filler grade and loading also matter. A quick extrusion rate and surface finish trial serves as the practical check.
How do I begin an evaluation?We provide a free 1kg test sample along with current technical data. The typical first step is to compare it against your existing plasticizer, measuring color difference after accelerated weathering.
Request a sample and recommendation
Tell us your sealant system and appearance requirements, and our team will provide a 1kg complimentary DB77 testing sample, shipped worldwide via DHL or FedEx. Trial order MOQ is 1 MT; bulk shipments are loaded as 23 MT flexitank containers from Ningbo or Shanghai.
Related grade
DB77 · DB77 Plasticizer for Construction and Automotive Sealants
Regulatory and standards references
The links below lead to official EU, US, and ISO sources for the compliance frameworks discussed on this page. DOBO does not control third-party content; the official text and regulations of the buyer's market take precedence.
- ECHA — Understanding REACHEU registration, evaluation, authorisation and restriction of chemicals (REACH), including the Candidate List of substances of very high concern.
- EUR-Lex — Directive 2011/65/EU (RoHS 2)Restriction on the use of certain hazardous substances in electrical and electronic equipment; Annex II lists restricted substances and their maximum concentrations.
- eCFR — 21 CFR 175.300US FDA regulations for resinous and polymeric coatings intended for repeated use as food-contact surfaces, including extraction testing conditions.
- ASTM — Plastic and plasticizer standardsASTM International publishes the test methods referenced in our TDS, including plasticizer sampling and chemical analysis, tensile properties, and heat-aging procedures.
- ASTM — Plastic and Plasticizer Testing StandardsASTM International has published the test methods referenced in the TDS, covering sampling and chemical analysis of plasticizers, as well as tensile properties and thermal aging procedures.
- ISO — ISO 10993-1Biological evaluation of medical devices — Part 1: Evaluation and testing within a risk management process, establishing the foundation for biocompatibility programs.
Request a 1 kg Free Sample & Full COA/TDS
Test DB77 using your own formulation. The request below is pre-filled with the grade discussed in this whitepaper, along with the specification, documentation, and sample shipping confirmation.
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