Some may be wondering about polypropylene material in clothing.
Polypropylene is probably the warmest out of all the synthetic materials. I may be wrong, but it feels like it could be slightly warmer than acrylic. It is still not as warm as wool, but seems to come close.
Wearing polypropylene is like being wrapped with an insulating layer of fat. This may sound like a strange analogy but I mean you can feel that polypropylene does not conduct heat as much as polyester. It feels warmer to the touch than polyester.
Polypropylene is very water resistant. It almost completely sheds water and hardly absorbs any water at all. It's a great material for very extremely wet conditions, where clothes are likely to end up soaked.
Something else people may not realize about polypropylene until they try it for themselves, it is extremely lightweight. I mean, for the same bulk and size volume it noticeably weighs less than polyester or cotton. That's not really an important thing, but it is just a little added plus.
Polypropylene seems particularly suitable for socks. It has some kind of subtle weird properties compared to polyester. Polypropylene seems to have even more "grip" than polyester, while at the same time having less irritating friction. I think the fibers of polypropylene are a little thicker than polyester. However, due to the chemical properties of polypropylene, it is more "buttery" and slippery (think a little like teflon). The bigger coarser fibers mean more grip, but the more sliding nature of the material when it rubs against skin means less uncomfortable friction and less abrasion.
But polypropylene has some downsides as well. If there is any risk or danger from fire, it is absolutely the worst material to be wearing, worse than any other synthetic fiber. Not a good idea to wear if there is any possible worry about fire hazard whatsoever. (It has the lowest melting point of any synthetic fiber, so easily melts, and it completely melts rather than forming any solid char whatsoever, which means very horrible burns if it is against the skin in a fire. It also is more flammable than any other synthetic fiber)
If you're going to be around a big campfire, probably not a good idea to choose it.
A polypropylene sweater which commonly has an inner layer of fleece will shed a lot of fibers, especially when it is in the washing machine. This can be annoying and get a lot of unsightly little fibers onto other clothes. The shedding of all these fibers is not considered to be very good for the environment, and there even could be some long-term health danger that the human body could uptake some of this "microplastic". (Not only does polypropylene fleece lining shed far more than on polyester, but polypropylene is also more fat soluble so the body could uptake and absorb it more easily. When I say "fleece lining" I am referring to the more "fuzzy" inner side of nearly all regular hoodies)
Polypropylene also does not really breathe at all, and is even slightly worse than other synthetic fibers in this regard (though the different types of synthetics are really not so much different from each other).
Against the skin, some picky or sensitive people might find polypropylene to feel a little bit "slick" and "oily", even worse than polyester. However, despite this, polypropylene does not have a certain "sick" uncomfortable feeling that many people notice polyester has (that is due to electrostatic charge with polyester pulling negative electric charge away from skin). Polypropylene also builds up less annoying static charge than polyester does, when for example peeling off a sweater layer.
Polyester is considered a "dry" fiber, but polypropylene is even a little bit more dry than polyester.
I feel like polypropylene could have a lot of utility in socks, since it is almost as warm as wool, but polypropylene is a much more durable fiber than wool, or even acrylic, and will not wear holes in the sock. It will also keep feet warm more than any other material if the shoes get completely soaked with water.
Some might be considering it for a base layer, but I think taking into account safety considerations it might just be more practical to choose a regular polyester base layer, or merino wool, or a merino-poly "Smartwool" blend.
I had someone I know test some polypropylene sweatpants riding a motorcycle in cold conditions, and their feedback suggested that wind resistance made more of a difference in this situation, the polypropylene did not keep the legs as warm because it let some air through, compared to regular motorcycle performance riding pants. But that probably would not be the case in most other conditions.
Polypropylene is probably the warmest out of all the synthetic materials. I may be wrong, but it feels like it could be slightly warmer than acrylic. It is still not as warm as wool, but seems to come close.
Wearing polypropylene is like being wrapped with an insulating layer of fat. This may sound like a strange analogy but I mean you can feel that polypropylene does not conduct heat as much as polyester. It feels warmer to the touch than polyester.
Polypropylene is very water resistant. It almost completely sheds water and hardly absorbs any water at all. It's a great material for very extremely wet conditions, where clothes are likely to end up soaked.
Something else people may not realize about polypropylene until they try it for themselves, it is extremely lightweight. I mean, for the same bulk and size volume it noticeably weighs less than polyester or cotton. That's not really an important thing, but it is just a little added plus.
Polypropylene seems particularly suitable for socks. It has some kind of subtle weird properties compared to polyester. Polypropylene seems to have even more "grip" than polyester, while at the same time having less irritating friction. I think the fibers of polypropylene are a little thicker than polyester. However, due to the chemical properties of polypropylene, it is more "buttery" and slippery (think a little like teflon). The bigger coarser fibers mean more grip, but the more sliding nature of the material when it rubs against skin means less uncomfortable friction and less abrasion.
But polypropylene has some downsides as well. If there is any risk or danger from fire, it is absolutely the worst material to be wearing, worse than any other synthetic fiber. Not a good idea to wear if there is any possible worry about fire hazard whatsoever. (It has the lowest melting point of any synthetic fiber, so easily melts, and it completely melts rather than forming any solid char whatsoever, which means very horrible burns if it is against the skin in a fire. It also is more flammable than any other synthetic fiber)
If you're going to be around a big campfire, probably not a good idea to choose it.
A polypropylene sweater which commonly has an inner layer of fleece will shed a lot of fibers, especially when it is in the washing machine. This can be annoying and get a lot of unsightly little fibers onto other clothes. The shedding of all these fibers is not considered to be very good for the environment, and there even could be some long-term health danger that the human body could uptake some of this "microplastic". (Not only does polypropylene fleece lining shed far more than on polyester, but polypropylene is also more fat soluble so the body could uptake and absorb it more easily. When I say "fleece lining" I am referring to the more "fuzzy" inner side of nearly all regular hoodies)
Polypropylene also does not really breathe at all, and is even slightly worse than other synthetic fibers in this regard (though the different types of synthetics are really not so much different from each other).
Against the skin, some picky or sensitive people might find polypropylene to feel a little bit "slick" and "oily", even worse than polyester. However, despite this, polypropylene does not have a certain "sick" uncomfortable feeling that many people notice polyester has (that is due to electrostatic charge with polyester pulling negative electric charge away from skin). Polypropylene also builds up less annoying static charge than polyester does, when for example peeling off a sweater layer.
Polyester is considered a "dry" fiber, but polypropylene is even a little bit more dry than polyester.
I feel like polypropylene could have a lot of utility in socks, since it is almost as warm as wool, but polypropylene is a much more durable fiber than wool, or even acrylic, and will not wear holes in the sock. It will also keep feet warm more than any other material if the shoes get completely soaked with water.
Some might be considering it for a base layer, but I think taking into account safety considerations it might just be more practical to choose a regular polyester base layer, or merino wool, or a merino-poly "Smartwool" blend.
I had someone I know test some polypropylene sweatpants riding a motorcycle in cold conditions, and their feedback suggested that wind resistance made more of a difference in this situation, the polypropylene did not keep the legs as warm because it let some air through, compared to regular motorcycle performance riding pants. But that probably would not be the case in most other conditions.
