Chemists at two German research institutes have devised lubricant-filled microcapsules that can be mixed into thermoplastics. They hope the material will extend the service life of plastic components and reduce resource use, said one of the lead researchers.
Self-lubricating plastics are not a new idea, and some use polymers such as silicone that migrate to the surface of the component where they form a boundary lubricant layer. Using a liquid lubricant contained in a microcapsule mixed with plastics such as polypropylene, poly oxy methylene and polyamide offers better distribution since it is only released when a capsule is destroyed by mechanical stress caused by friction, Monika Jobmann, head of the microencapsulation and polysaccharide chemistry department at the Fraunhofer Institute for Applied Polymer Research, told Lube Report.
Plastics research institute SKZ is the other partner in the joint research project. According to an SKZ press release, the aim of the investigations was to enable the use of liquid or paste-like lubricants.
“Due to the significantly greater variety of liquid lubricants and the possibility of integrating other additives into the base oil, the lubricants can be tailored to the matrix polymer and application,” Jobmann said.
Until now, liquid or paste lubricants could only be dosed by external addition or complex devices, Fraunhofer Institute said in a press release. Their microcapsules behave as a powder and so combine the advantages of solid and liquid lubricants.
“After the microencapsulation they are available as solids, with about 90% liquid oil content, and can be processed like any other solid lubricant,” said Jobmann.
According to Jobmann, the fields of application are diverse, ranging from gears, furniture, automotive components, hydraulic and pneumatic system sealants and the food processing industry, which often prefers to avoid external lubrication.
The benefits to end users include long-lasting friction reduction without re-lubrication, lubrication in areas that are difficult to access and reduced consumption, Jobmann said.