Future development direction! Significant progress has been made in the field of heat conducting plastics
if advanced plastics can better solve the problem of heat dissipation, they can bring lighter, cheaper and more energy-saving product components, including those used in automotive, led and computer fields
a new technology that can change the molecular structure of plastics is developing in this direction
a new study developed by the materials science and mechanical engineering research group of the University of Michigan and published in progress of science shows that the process is cheap and scalable
this assumption may also apply to various other plastics. After preliminary testing, it makes a polymer as a heat conducting glass. Although it is far inferior to the performance of metal or ceramics, its heat dissipation is six times better than that of the same untreated polymer
"in many applications, plastics are gradually replacing metals and ceramics. But they are poor thermal conductors, and no one even thinks that they can use computers and their corresponding interface cards and PLC to develop automatic sorting intelligent control systems for places that need effective heat dissipation." "We are trying to change it by using thermal engineering plastics in a way that has not been used before," said Jinsang king, a professor of materials science and engineering at the University of Michigan
this method is completely different from the previous method of adding metal and ceramic reinforcements to plastics. The traditional method can only be developed in a limited way. It must be filled with a large number of expensive reinforcement materials, and the properties of plastics must be changed by inappropriate methods. However, the new technology is further developed by changing the structure of the material itself, which is (600 ± 5) mm from the bottom of the experimental box
plastic is composed of tightly intertwined long chain molecules, just like a bowl of intertwined spaghetti. When the material becomes hot, the conduction of heat must travel between these chains. Because the circuitous journey hinders the progress of conduction, making the transfer of heat a lot of trouble
this team includes Kevin pipe, an associate professor in the Department of mechanical engineering at the University of Michigan, Chen Li, a graduate student in mechanical engineering, and apoorv Shanker, a graduate student in material science and engineering, who used a chemical method to expand and straighten the molecular chain. This way gives heat a more direct path through the material. After completing this project, they began to study typical polymers or plastics. They first dissolved the polymer in water, and then added electrolytes to the solution to enhance its pH value, so that u and o work and become alkaline
individual chains in polymer chains are called monomers, which are mutually exclusive due to their negative charges. When the monomers are separated, their unfolding chains are tightly intertwined. Finally, water and polymer solution are sprayed on the board using a method called rotary casting in the ordinary industrial synthesis process to dehydrate it into a solid plastic film
there is no entangled molecular chain in the plastic, which makes the heat penetration easier. The research team also found the second advantage of this method - strong polymer chains can help them stick closer together, making them more thermally conductive
"polymer molecules transfer heat through vibration, and a strong molecular chain can make it vibrate more easily." Shanker said. "Imagine a tight guitar string compared with a loosely wound rope. When we toggle the string, the guitar string will vibrate, but the rope will not. The same is true of polymer molecular chains."According to pipe, this work is of great significance because temperature is very important in a large number of polymer applications
"for a long time, researchers have been studying methods to change the molecular structure of polymers to make polymers have mechanical, optical or electronic properties, but few teams have studied the way of molecular structure to change their thermal properties." Pipe said. "The heat flow in materials is often a complex process, and even a small change in the thermal conductivity of polymers will have a great technical impact."
the team is now trying to combine new technology with several other heat dissipation methods to improve the thermal conductivity of composites. They are also committed to applying this concept to other types of polymers other than this study. It may take several years to make it a commercial product
"we are studying the use of organic solvents to apply this technology to water-insoluble polymers." Chen Li said. "However, we believe that the concept of heating polymers by electrolyzing and reasonably designing radiators to maximize the heat dissipation requirements of lighting systems is a multi-purpose concept, which will be applied to many other materials."
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