In building insulation, HVAC, and industrial piping systems, the service life and long-term stability of insulation materials are crucial considerations during selection. Rubber and plastic insulation materials, due to their good flexibility and stable closed-cell structure, are widely used in hot and cold water pipes, air ducts, and equipment insulation. Among these, aging resistance is one of the key indicators determining the long-term stable service life of rubber and plastic materials. This article will systematically explain the aging resistance of rubber and plastic materials from the perspectives of material structure, aging mechanism, and practical applications.

I. What is the Aging Phenomenon of Rubber and Plastic Materials?

Aging refers to the process by which the physical and chemical properties of a material gradually change under the influence of environmental factors during long-term use. For rubber and plastic insulation materials, aging typically manifests as:

Surface hardening and decreased elasticity

Reduced flexibility and the appearance of microcracks

Changes in thermal conductivity

Shortened service life

Factors affecting the aging of rubber and plastic materials mainly include temperature, oxygen, ultraviolet radiation, moisture, and chemical media.

II. Basic Structure and Aging Resistance of Rubber and Plastic Materials

1️⃣ Closed-Cell Foam Structure

Rubber and plastic materials are closed-cell elastic foam materials, whose internal structure consists of a large number of independent microbubbles. This structure has the following advantages:

Effectively blocks air and water vapor penetration

Reduces oxygen entry into the material's interior

Reduces the impact of environmental factors on the material's internal structure

The closed-cell structure is an important foundation for the good aging resistance of rubber and plastic materials.

2️⃣ Polymer Elastomer Substrate

Rubber and plastic insulation materials are usually made with synthetic rubber as the base material, through scientific formulation and foaming processes. These polymer materials themselves possess:

Good molecular stability

Strong fatigue resistance

Not prone to structural fracture within the normal operating temperature range

A reasonable molecular structure design makes rubber and plastic materials less prone to significant performance degradation during long-term use.

III. Formation Mechanism of Aging Resistance of Rubber and Plastic Materials

1️⃣ Antioxidant Capacity

In the atmospheric environment, oxygen is one of the important factors leading to material aging. During the production of rubber and plastic materials, the following methods are typically used:

Controlling the molecular chain structure

Adding stabilizers

Optimizing the foaming process

To slow down the oxidation reaction and thus improve the material's long-term stability.

2️⃣ Temperature Adaptability

Rubber and plastic insulation materials are generally suitable for a temperature range of approximately -40℃ to 105℃. Within this temperature range, the material maintains good flexibility and structural stability, and is not prone to significant aging due to alternating hot and cold temperatures.

In HVAC systems, frequent hot and cold cycles are common operating conditions, and the temperature resistance stability of rubber and plastic materials allows for good long-term performance in such environments.

3️⃣ Moisture Resistance and Moisture Proof

Because rubber and plastic materials have a closed-cell structure, moisture is difficult to penetrate the material, which greatly slows down the aging problems caused by humid environments. Good moisture proofing means:

Less susceptibility to performance degradation due to water absorption

Less susceptibility to mold growth

Relatively longer service life

This is one of the important reasons why rubber and plastic materials are widely used in pipe insulation. IV. Aging Resistance Performance of Rubber and Plastic Materials in Practical Applications

1️⃣ Building and HVAC System Applications

In building air conditioning systems and hot and cold water pipes, rubber and plastic materials are typically used for long-term operation. Their aging resistance ensures:

The insulation layer maintains structural integrity after years of use.

The surface does not crack or powder.

The thermal conductivity changes minimally.

This helps reduce the frequency of later maintenance and replacement.

2️⃣ Industrial Equipment and Pipeline Insulation

In industrial environments, rubber and plastic materials are commonly used for insulation of medium- and low-temperature equipment and pipelines. Excellent aging resistance allows it to:

adapt to changes in ambient temperature

resist a certain degree of environmental stress

maintain stable thermal insulation performance

V. Factors Affecting the Aging Resistance of Rubber and Plastic Materials

It should be noted that the aging resistance of rubber and plastic materials is also affected by the following factors:

Installation environment: Long-term exposure to strong ultraviolet radiation requires the use of a protective layer.

Construction quality: Improper joint treatment may accelerate aging.

Operating temperature range: Exceeding design conditions may affect service life.

Proper selection and standardized construction are important prerequisites for ensuring the full realization of the aging resistance of rubber and plastic materials.

The excellent aging resistance of rubber and plastic materials is mainly due to their closed-cell structure, high-molecular elastomer matrix, and stable physicochemical properties. In conventional application environments such as building HVAC and industrial pipelines, rubber and plastic insulation materials can maintain flexibility and thermal insulation performance for a long time, meeting the requirements of stable system operation. Through reasonable design, correct construction, and standardized use, the aging resistance advantages of rubber and plastic materials can be fully realized.