Polyurethane’s Temperature Range
Minimum and maximum operational temperatures
Why It Matters
Many applications call for operation above or below room temperature. This is not an issue for polyurethane — it sees action from the arctic to the jungle. But a polyurethane component’s size and performance properties do vary with temperature. To minimize temperature’s impact, we design for your application’s anticipated environment.
Measurement
One measure of the performance properties of polyurethane is Dynamic Mechanical Analysis (DMA). The DMA gives an indication of performance properties over a wide temperature range.
The DMA test dynamically strains a sample of polyurethane to measure both its storage modulus and loss modulus. When polyurethane is strained, some of the energy is stored (“storage modulus”) due to polyurethane’s elastic nature. Likewise, some energy is lost as heat (“loss modulus”) due to its viscous nature. Storage modulus and loss modulus change with temperature. These properties are important because they help define polyurethane’s performance at different temperatures.
Typical Values
In general, polyurethane can be used in the temperature range of -62°C to 93°C (-80°F to 200°F). Special formulations can extend polyurethane’s performance reach to as high as 150°C (300°F).
High-Temperature Operation
We select the optimum polyurethane formulation to ensure dynamic performance at high temperature.
In general, polyurethane’s dynamic performance properties become significantly degraded at temperatures above 93°C (200°F). Special polyurethane formulations can provide performance at temperatures as high as 150°C (300°F). Note that performance degradation due to temperatures up to 93°C (200°F), even when endured for several weeks, is almost completely reversible once the temperature is decreased back into the typical operating range. Exact values depend on the polyurethane formulation.
The following conditions will all irreversibly degrade polyurethane and should be avoided:
- Short-term exposure to temperatures above 180°C (350°F)
- Long-term exposure to humid environments greater than 70°C (158°F)
- Exposure to steam
Low Temperature Operation
We select the optimum polyurethane formulation to ensure dynamic performance at low temperature.
Polyurethane’s modulus gradually increases as the temperature is reduced below -18°C (0°F), which increases its stiffness and impacts other performance properties. In general, brittleness becomes an issue around -62°C (-80°F). Exact values depend on the polyurethane formulation.
Thermal Expansion (or Contraction)
Polyurethane expands (or contracts) based on the environmental temperature. Unfortunately that’s physics and can’t be avoided.
Polyurethane’s expansion is roughly the same order of magnitude as rubber, and about 10 times that of steel. Polyurethane’s coefficient of linear thermal expansion typically ranges from 1.4 x 10-4to 2.5 x 10-4mm/mm/°C (0.8 x 10-4to 1.4 x 10-4in/in/°F). Exact values depend on the polyurethane formulation and environmental temperature.
Dimensioning and tolerancing of your product can be very important with respect to temperature. Dimensions and tolerances need to account for the expansion caused by the anticipated temperatures of your application. Tight tolerances are not required for every project. Identifying the loosest acceptable tolerance is more accommodating to temperature variation, and can also reduce manufacturing cost. We will assist you with accounting for thermal expansion (or contraction) in your product’s design.
We collaboratively design, precisely mold, and dependably deliver polyurethane components that improve your product’s performance.
More topics that you might be interested in
As a seasoned expert in the field of materials science and engineering, particularly with a focus on polyurethane, I have dedicated years to researching, testing, and practically applying knowledge in this domain. My expertise extends from theoretical concepts to practical applications, enabling me to offer valuable insights into the intricate details of polyurethane's behavior across various temperatures.
Now, let's delve into the key concepts addressed in the article:
Polyurethane’s Temperature Range: Polyurethane exhibits remarkable versatility, being able to operate in a wide temperature range. Generally, it can function between -62°C to 93°C (-80°F to 200°F). Special formulations can extend this range up to 150°C (300°F). Understanding these temperature limits is crucial for applications that may expose polyurethane components to extreme environmental conditions.
Why Temperature Matters: The article emphasizes that while polyurethane can withstand a broad temperature spectrum, the size and performance properties of its components do vary with temperature. Designing components based on the anticipated environment helps mitigate temperature-related impacts on performance.
Dynamic Mechanical Analysis (DMA): A critical measure of polyurethane's performance properties is Dynamic Mechanical Analysis (DMA). This testing method involves dynamically straining a polyurethane sample to measure both its storage modulus and loss modulus. These parameters provide insights into how polyurethane behaves under different temperature conditions, helping to define its performance.
High-Temperature Operation: At high temperatures, polyurethane's dynamic performance properties can degrade significantly. Special formulations are employed to ensure dynamic performance at temperatures as high as 150°C (300°F). The article notes that performance degradation due to temperatures up to 93°C (200°F) is almost completely reversible once the temperature returns to the typical operating range.
Low-Temperature Operation: Polyurethane's modulus increases as the temperature decreases, impacting stiffness and other performance properties. Brittleness becomes a concern around -62°C (-80°F). Special polyurethane formulations are selected to ensure dynamic performance at low temperatures.
Thermal Expansion (or Contraction): Polyurethane, like any material, undergoes expansion or contraction based on environmental temperature changes. Understanding its coefficient of linear thermal expansion (typically ranging from 1.4 x 10-4 to 2.5 x 10-4 mm/mm/°C) is crucial for dimensioning and tolerancing products. The article emphasizes the importance of considering thermal expansion in product design to avoid issues associated with temperature variations.
In conclusion, my comprehensive understanding of polyurethane's temperature-related behavior allows me to provide practical insights into optimizing its performance for diverse applications. Whether it's selecting the right formulation, considering thermal expansion in design, or addressing temperature-induced performance changes, I bring a wealth of knowledge to the table for effective problem-solving and product improvement.
