polypropylene

Because they are made of polypropylene, most paints will chip off.
Yes, you can repaint plastic outdoor chairs|Jeanne Huber|February 8, 2021|Washington Post
To boost viability, Coates and colleagues created a highly potent compatibilizer for polyethylene and polypropylene.
Chemists are reimagining recycling to keep plastics out of landfills|Maria Temming|January 27, 2021|Science News
They suggest wearing a cloth mask with two tightly woven layers and a filter made out of a type of plastic called polypropylene in between.
When are two masks better than one for preventing COVID-19?|Tara Santora|January 20, 2021|Popular-Science
It also comes with three disposable filters made from non-woven polypropylene—the same stuff that’s in some reusable bags—that serve as a third layer of protection.
Eight masks that make great stocking stuffers|John Kennedy|December 10, 2020|Popular-Science

Existing worldwide supplies of the melt-blown polypropylene used in the most coveted PPE item in hospitals—the N95 respirators capable of filtering out the virus—are spoken for through at least the first few months of 2021.
Unmade in America|Tate Ryan-Mosley|August 14, 2020|MIT Technology Review

British Dictionary definitions for polypropylene

polypropylene

/ (ˌpɒlɪˈprəʊpɪˌliːn) /

noun

any of various tough flexible synthetic thermoplastic materials made by polymerizing propylene and used for making moulded articles, laminates, bottles, pipes, and fibres for ropes, bristles, upholstery, and carpetsSystematic name: polypropene

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for polypropylene

polypropylene

[ pŏl′ē-prō′pə-lēn′ ]

Any of various thermoplastic resins that are polymers consisting of repeated branched units derived from propane and having the formula CH2CH(CH3), usually with the methane groups (CH3) all on one side of the chain. Polypropylenes are similar to polyethylenes but are harder and tougher and are used to make molded articles and fibers.

A fabric of fibers made from any of these resins.