The Basic Chemical Structure Of Plasticizers
Plasticizer is the largest additive in plastic additives, mainly DOP, BOP, DIBP and DIDP, China has become the largest producer and exporter of plasticizers in Asia. Reply "Auxiliary" for more information
First, the concept of plasticizer
Any material that can reduce the melting temperature of the resin, improve the flowability of the resin in the molten state and the softness of the product are called plasticizers. When the plasticizer is added to the polymer material, the melt viscosity, the glass transition temperature and the elasticity can be reduced without changing its basic chemical properties, thereby improving the workability and improving the softness of the product and Tensile properties of the material
Second, the basic chemical structure of plasticizers
1. consists of a combination of a polar group and a non-polar group
Third, the plasticizer plasticizer principle
1. The factors that counteract plasticization in polymer materials
1) intermolecular force
The polymer material composed of macromolecule chains with high regularity can be locally crystallized under appropriate conditions, and the crystallization area is more stable than the amorphous region, the free space is smaller and more difficult to plasticize. In short, Polymeric materials are plasticized and must weaken their intermolecular forces and destroy the crystalline zone. Reply "Auxiliary" for more information
2. Plasticizer plasticizer principle
On the principle of plasticizer, the industry has a variety of theoretical point of view, such as: lubrication theory, gel theory and free volume theory, the most commonly accepted reference is: plastic polymer plastic material is due to high-polymer materials The effect of aggregation between molecules is weakened. That is, the plasticizer molecules are inserted between the polymer molecular chains, weakening the interaction between the polymer molecular chains, resulting in increased mobility of the polymer molecular chains, reducing the crystallinity of the polymer, Plasticizer thereby increasing the plasticity of the polymer The
3. Plasticizer anti-plasticizing effect
When the amount of plasticizer to a certain extent, but will cause the polymer material hardness increases, the elongation decreases, the impact of the phenomenon of reduced strength. It is generally believed that the reason for the anti-plasticization effect is that a small amount of plasticizer makes the polymer chain easy to move, Plasticizer and promotes the orientation and crystallization of the amorphous region.
Classification of plasticizers
1. According to the introduction can be divided into: within the plasticizer and plasticizer
Internal plasticizers - Plasticizers for polymer materials can also be introduced in a copolymerized or grafted manner, also known as "bonded plasticizers", with the advantage of high physical durability, Plasticizer but difficult to implement, And other shortcomings, it is not commonly used.
External plasticizer - to add the way to the introduction of polymer materials, plasticizers, also known as "additive plasticizer", its outstanding advantage is to facilitate the flexibility to adjust the amount of control and control of plasticity, is commonly used plastic Agent, commonly referred to as plasticizer that is outside the plasticizer. Reply "Auxiliary" for more information
2. According to the compatibility can be divided into the main plasticizer and auxiliary plasticizer
The main plasticizer - with the basic polymer materials (resin, raw rubber) compatibility is better, its molecules can not only enter the polymer material of the amorphous area, Plasticizer and can be inserted into the crystallization zone, also known as "solvent-based plasticizer "Can be used alone. Auxiliary plasticizer - with the basic polymer materials (resin, raw rubber) compatibility is poor, the molecules can only enter the amorphous material of the amorphous area, and can not be inserted into the crystallization zone, only with the main plasticizer Use, can not be used alone.
3. According to the applicability can be divided into general-purpose, high-performance and special plasticizer
Universal plasticizer (GP) - cost-effective, good performance and good applicability of plasticizers. Phthalate-based plasticizers are typical general-purpose plasticizers. High Performance Plasticizer (PP) - A plasticizer that provides certain / certain outstanding properties, including:
① strong solvent type (PP-SS) plasticizer: to provide particularly strong plasticizing properties, commonly used mainly polar strong special phthalate, high aromatic ring content of non-phthalic acid Esters such as benzoate, tricresyl phosphate and the like.
② low temperature resistant (PP-LT) plasticizer: to provide particularly good resistance to isothermal performance, also known as cold plasticizer, commonly used mainly aliphatic dibasic acid esters.
③ low volatile (PP-LV) plasticizer: with a particularly low volatility, also known as heat-resistant plasticizer, commonly used mainly trimellitate and polyester.
Special type of plasticizer - can provide a certain / some special properties of plasticizers, including:
① low diffusion (SP-LD) plasticizer: a particularly low diffusion, also known as durability plasticizers, commonly used mainly polyester.
② heat-stable (SP-Stab) plasticizer: both PVC auxiliary heat stabilizer function, commonly used mainly epoxy compounds.
③ flame retardant (SP-FR) plasticizer: both flame retardant function, commonly used mainly phosphate and halogenated hydrocarbons.