LocksOfLuV said:
Navs, good info. I swear I am not trying to pick you apart but can you tell me which ingredients exactly actually does the protecting and how much heat can it withstand before it molecularly fall apart-for lack of better words? I find myself to be highly knowledgable about hair, and science or no science, I can tell you that a heat protectant can only do so much. I do agree that it is better than nothing though.
I don't really believe that there really is any man-made chemical (in hair products) that can continuously protect ANYTHING (besides a NASA made sun suit lol) from up to 400 degrees of direct heat. If that is enough to burn flesh, and plastic, then surely that is enough to pentrate these so called protective layers.
I don't disagree that heat is modertion is cool. But I do think that you have to be smart about it. Hair is not a strong cryptonite-titanium-steel substance. It is protein which is said to break down in high temperatures. Over time, no amount of heat protectants can save you. I am I extremely weary of any complany (who's #1 goal is to sell their product-let's not forget that) claiming to do so.
Your hair is made up of chemical bonds (as is everything else in this world). Understanding organic chemistry (that has a key in everything) leads to truly understanding how things work around you. You can see how something looks from the outside and if it works or not, but that is different than knowing the chemical mechanisms that go on to MAKE it work. Products will change, methods will change, but guess what's never gonna change? The chemistry that makes up your hair (bonds change, but the atoms do not). For instance, keratin will always be keratin and if you come into a product that contains keratin, the broken keratin bonds are going to reform because NATURE will always take its course.
Like I said, each atom forms a bond and has its own level of bond strength. Before the heat can destroy the bonds in your hair, it has to FIRST destoy the bonds in the PROTECTANT. If you are not using a temp high enough to destroy the bonds in the protectant, then guess what? It's not gonna touch your hair. Even though these chemicals are "manmade," (although there are reconstructors that use human hair keratin), no man is creating these atoms, only causing the bonds to form back into molecules like they would NATURALLY. You can create bonds in a certain way to form manmade products in different shapes (for instance, a diamond looks different than a piece of regular black carbon but they are both carbon, and a human being can cut a diamond in the way you personally request), but the bonding occurs naturally on its own.
As for which ingredients do the protecting, look for the silicones or strong polymers (proteins are just polymers of amino acids themselves) . Amodimethicone has a different chemical makeup than cyclomethicone. Dimethicone has several different forms within itself that vary when you change a functional group for instance. For instance, regular dimethicone is C6H18OSi2 So take the O (oxygen) bonded to the silicone (Si) as an example (Si-O-Si). Si-O has a bond dissociation energy of about 108 kcal/mol (this is just one type of bond in dimethicone now). But if you take another silicone that might have Si-C in it, Si-C has a bond dissociation energy of 306 kj/Mol. But anyway, let's just focus on dimethicone for my example. Little dimethicone (one of many in a silicone containing heat protectant) here is protecting your hair, right? Now, once you exceed the energy needed to break the bond in dimethicone, say goodbye to your hair bonds because they are about to be zapped. That is the ONLY way a heat protectant isn't gonna work--when the energy from the flat iron (or whatever other form of heat) you are using exceeds that of the bonds of all the silicones (and trust me, there are many more than my little example) in the protectant, causing them to break and letting the heat get through.
As for what temperature can be used to break a bond, it also depends on the condition of the bond itself. If it's a new bond, higher temps may be needed to break it depending on the nature of the atoms. But if the bond is already weak, 200 degrees could be the amount of energy added to that that has already weakened it before and will equal the maximum amount of energy for the bond to break. Bond dissociation energy is just the amount of heat needed to be put into a molecule to break the bonds (usually measured in kcal/mol or kJ/mol, keep in mind, these are not equivalent to degrees celsius, they are different units). It takes different levels of energy to break different bonds. For instance, take the hydrogen bromi
de bond. H-Br has a bond energy of 366, H-H 436, Br-Br 193 (all in kJ/mol). Now, the amount of energy put IN is what's gonna break it (some energy will also be released, so it would take 732 kj taken in to break the bonds). When you reach those energies, you will break those molecules back into their original atoms.
Now, Si-
OH bond in a silicone product can survive at over 1000 degrees celsius (which is not equivalent to the kJ/mol or kcal/mol number, mind you), and I KNOW no one is using a flat iron at 1000 degrees Celsius (if you are, get your head checked).
But like I said, EVEN when a bond IS broken, the atoms are NEVER destroyed. If they were, then that would disprove the laws of nature. When flesh is burned to a crisp, the atoms that make it up are still there, they have just been chemically changed. So even though hair is no magic material (as I have said before myself), the atoms do still remain and as long as those atoms are there and the strand has not disintegrated into thin air, the bonds can and will form back when the appropriate atom comes along because nature is gonna take its course and there's nothing you can do to stop it from doing so (unless there was no hair coming out of the follicles at all--no hair, no keratin, no bonds).
Now, let me make this clear...I am in no way saying have a free for all with heat just because the bonds will form back since the atoms remain. If you damage your hair enough and it breaks off, the atoms of the hair will be on the floor, not still connected to your hair strand, and you DON'T want that.
