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Materials and Construction Research Division
Polymeric Materials Group
Competition within the construction materials community has drastically increased with globalization of each industry sector. As is the case for the high technology industries, this globalization of effort has greatly increased the competitive pressures of reducing the time-to-market for new construction materials and products. Currently time-to-market is largely controlled by the time required to generate a performance history for a product. Performance histories are established through a series of time-consuming field and laboratory exposure studies, often taking between 5 and 15 years to complete. The mission of the service life prediction program is to greatly reduce the time-to-market for new products. Developing and implementing advanced methods and metrologies for quantitatively and reliably predicting the service life of existing and new products can accomplish this. The methodology used in making these service life estimates is called reliability theory and life testing analysis. This methodology has had a long and successful history of application in predicting the service life of electronics, aerospace, nuclear, and medical products.
1) Implementation of a reliability theory and life testing approach in predicting the service life of polymeric construction materials includes six major activities. These activities include:
2) identification, measurement, and characterization of material properties and failure mechanisms linked to service life performance of a product;
3) design of laboratory experiments in which the intensity of each weathering factor can be precisely and independently controlled over time and over space;
4) quantitative characterization of weathering factors in the field and laboratory using metrics that are comparable and useful in predicting the service life of polymeric materials;
5) derivation and verification of service life prediction models having a basis in a material’s failure physics;
6) analysis, storage, and retrieval of data in a standardized format useful for predicting the service life dissemination of knowledge to customers.
The majority of this research is being performed at the fundamental mechanistic level. Sponsors include the Federal Highway Administration (FHWA), Forest Products Laboratory, Housing and Urban Development (HUD), Smithsonian Environmental Research Center, Wright-Patterson Air Force Base, and numerous industrial partners.
A number of Industry/NIST consortia have been established, or are in the process of being established to help industry meet its needs in predicting the service lives of polymeric building materials:
- Objectives
: to implement a reliability-based methodology and develop metrologies for linking field and laboratory exposure results. Established in 1994 and is expected to continue into its third 3-year phase beginning in June, 2001.For more information, contact Jonathan W. Martin
- Objectives
: to understand the driving forces and interactions that cause interphase development and to develop methods for quantitative characterization of heterogeneous materials on the nanoscopic level.- Established January 2001.
For more information, contact Tinh Nguyen
- Objectives
: to implement a reliability-based methodology and develop metrologies for linking field and laboratory exposure results.- Presently being formed.
For more information, contact Christopher C. White
- Objectives
: to develop advanced measurement methods and predictive models for accurately describing the light scattering and appearance properties of fabricated objects.- A pre-consortium workshop has been scheduled for May 2001.
For more information, contact LiPiin SungOther active project areas include:
- Lead in Household Paint
- Objective
: to address policy issues as directed by HUD.For more information, contact Walter J. Rossiter
Photo reactivity of Titanium Dioxide (TiO2)
- Objective
: Development of novel metrologies for the measurement of photoreactivity, including non-contact methods and methods for use with nanostructured materials.
For more information, contact Joannie W. Chin or Stephanie Scierka.
For more information, contact Christopher C. White. Joannie Chin, Leader
Polymeric Materials Group
(301) 975-6815 joannie.chin@nist.gov
NIST SPHERE (Simulated Photodegradation by High Energy Radiant Exposure) technology developed and patented by NIST researchers working on the Service Life Prediction of Polymer Coatings consortium.
Thermal image of the NIST SPHERE taken with a thermal camera.
Laser scanning confocal microscope image of a coating containing interference pigments. In this image, green laser light was used. Interference fringes are observed for some pigments, where as other pigments that are transparent to green light are not visible in this image but are observed under different laser light.
Topographic image, taken using an atomic force microscope, of a polyurethane coating after laboratory exposure to ultraviolet radiation, elevated temperature, and high relative humidity.
Computer-generated image of an automobile with a metallic-flake clearcoat/basecoat paint system. Optical reflectance and scattering data measured at NIST were used to produce a more accurate rendering of this coated object.
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Last updated: 6/11/2007