닐스 로고

• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

Thermal conductivity in polymers is a critical property that influences their performance in applications ranging from electronics insulation to heat exchangers and automotive components

Polymers lack free electrons, so heat moves through vibrational waves in their molecular chains—a process far more sensitive to crystallinity, orientation, and processing history than in metals

When compared side-by-side, seemingly identical polymers can exhibit wide disparities in thermal performance, highlighting the importance of detailed material analysis

Polyethylene, especially high density polyethylene, exhibits relatively low thermal conductivity, typically around 0.3 to 0.5 watts per meter-kelvin

This makes it a good insulator for packaging and construction uses

However, when polyethylene is processed into highly oriented films or fibers through stretching and drawing, its thermal conductivity can increase substantially due to improved chain alignment and reduced amorphous regions

Under extreme orientation, تولید کننده گرانول بازیافتی certain polyethylene fibers have achieved thermal conductivities as high as 50 W

(m·K)

The presence of methyl side groups in polypropylene disrupts chain alignment, limiting the gains in thermal conductivity during orientation

Polystyrene, used extensively in foam insulation, has even lower thermal conductivity, often below 0.05 watts per meter-kelvin, making it ideal for thermal barrier applications

In contrast, aromatic polymers like polyimide and polyetheretherketone show higher thermal conductivity, typically in the range of 0.2 to 0.5 watts per meter-kelvin, due to their rigid, planar molecular chains that facilitate better phonon transport

These materials are often used in high-temperature environments where both mechanical strength and moderate heat dissipation are required

Modern composite strategies incorporate nano-fillers like graphene, carbon nanotubes, and ceramic oxides to significantly enhance heat conduction in polymers

Thermal performance can be tuned from 1 to over 10 W

In one notable case, a 30% graphene-filled nylon composite demonstrated thermal conductivity rivaling that of alumina ceramics

Thermal conductivity in polymers is not inherent but malleable, shaped by molecular structure, fabrication methods, and nanocomposite engineering

While traditional polymers remain excellent insulators, modern modifications are enabling them to serve as active thermal management materials in advanced technologies

A nuanced grasp of these differences empowers engineers to match polymer properties precisely to thermal demands, ensuring optimal trade-offs between performance, cost, and weight in diverse sectors