Plasticizer Light Stability Stability
Plasticizer is a polymer auxiliaries, its wide variety, is a colorless, odorless liquid, widely used in industry. Often used in plastics, rubber, adhesives, cellulose, resin, medical Equipment, cables and other thousands of products. Epoxy plasticizer of the main varieties: epoxy soybean oil, Plasticizer epoxy acetyl linoleic acid methyl ester, epoxy bran oleate and so on. In PVC products, plasticity And the stability of the use of a wide range of features. Epoxy plasticizer is a natural oil in the organic peroxy acid epoxidation reaction and made a class of excellent plasticizer, very little toxicity, highlight the advantages of non-toxic, Heat resistance and light stability.
The role of plasticizers in high-quality plastic products is indispensable. Its variety structure is constantly adjusting the changes, the rapid development of new technology, more and more new varieties, Plasticizer detection means more first The method is more reasonable, and the plasticizer is progressing in the cycle of "development - application - toxicology test - risk assessment - redevelopment". Therefore, the correct use of plasticizers Is the key to the healthy development of the industry. And to do this, plasticizer business should be in the structural adjustment efforts. Plasticizer Abroad is vigorously promoting known as non-toxic or environmentally friendly and biodegradable Plasticizer.
Plasticizer: is widely used in industry, polymer additives, in the plastic processing to add this material, can make its flexibility to enhance, easy processing.
Plasticizer according to its role is divided into plasticizer and plasticizer.
The inner plasticizer is the second monomer introduced during the polymerization of the polymer, and since the second monomer is copolymerized in the molecular structure of the polymer, Plasticizer the degree of polymer chain is reduced, i.e., the polymer The crystallinity of the molecular chain.
The outer plasticizer is a low molecular weight compound or polymer that is added to the polymer that needs to be plasticized to increase the plasticity of the polymer. The interaction with the polymer is mainly at elevated temperatures Swelling, forming a solid solution with the polymer.
The mechanism of action of the plasticizer is that the plasticizer molecules are inserted between the polymer molecular chains, weakening the stress between the polymer molecular chains, Plasticizer resulting in increased mobility of the polymer molecular chains, The crystallinity of the sub-chain, thereby increasing the plasticity of the polymer, that is, the main factor against the plasticization of the polymer molecular chain between the stress and polymer molecular chain crystallinity, and they depend on the poly Chemical structure and physical structure of the compound.
When the plasticizer is added to the polymer, the interaction between the plasticizer and the polymer molecules is important to each other, unless all of these interactions (plasticizers And plasticizers, between the plasticizer and the polymer, between the polymer and the polymer) are the same size, it may not have plasticization and anti-plasticizing effect.
1. Van der Waals force van der Waals is a weaker gravitational force between molecules and molecules in the state of material aggregation. Van der Waals forces include dispersive power, Plasticizer induced force and orientation force. Only a few angels.
(1) Dispersion force exists between all polar or nonpolar molecules, due to the interaction of tiny instantaneous dipoles to make the adjacent dipole in a heterogeneous adjacent state.
However, only in nonpolar systems, such as benzene, polyethylene or polystyrene, the dispersion of power accounted for more important components.
(2) Induction force When a molecule with a fixed dipole induces an induced dipole in an adjacent nonpolar molecule, Plasticizer the gravitational force between the induced dipole and the intrinsic dipole is called the inducing force.
The aromatic compounds are particularly strongly affected by the high polarization of the π electrons, such as between low molecular weight esters and polystyrene or between benzene and polyvinyl acetate.
(3) orientation force When the polar molecules close to each other, due to the inherent dipole orientation caused by a force between the molecules called the orientation force, such as ester plasticizer and PVC or with nitrocellulose Interaction is a representative example.
Hydrogen bonds are hydrogen atoms, and hydrogen bonds are formed in the molecule, sometimes in the molecule. phase The interaction of the plastic molecules into the polymer molecules, Plasticizer if the hydrogen bonds along the polymer molecular chain distribution of the more close to the role of plasticizer insertion is stronger.Therefore requires plasticizers and poly The molecular molecules can produce similar strong effects.On the other hand, as the temperature increases, the intermolecular attraction is significantly weakened by the reduction of hydrogen bonds, because the thermal motion of the molecules hinders the polymerization The orientation of molecules.
3. The molecular chain of the polymer with the structure of the structure can be crystallized under appropriate conditions, that is, the chain molecules from the volume and the messy state into a tightly folded into a regular state in the general conditions, Industrially produced polymers can not be completely crystallized, Plasticizer and are often formed by the crystalline regions scattered in the amorphous region.
It is clear that it is much more difficult for the molecules of the plasticizer to be inserted into the crystalline region than to insert the amorphous region because the free space between the crystalline region and the polymer and the chain is minimized. If the molecules of the plasticizer can only be inserted In the amorphous region of the partially crystallized polymer, the plasticizer is a non-solvent type plasticizer, the so-called auxiliary plasticizer, if the molecules of the plasticizer can only be inserted into the amorphous region of the polymer While the crystal area can be inserted, then the plasticizer is a solvent-based plasticizer, the so-called main plasticizer.