Broadly speaking, all additives that improve the thermal stability of polymers are called heat stabilizers, and PVC heat stabilizers are mainly used for PVC and other chlorine-containing polymers.
Speaking of the characteristics of PVC heat stabilizers, do you understand?
Today, China's Heat Stabilizer factory NOVISTA GROUP tells you about the characteristics of PVC heat stabilizers, as follows:
(1) Compatibility
It is always hoped that the
PVC stabilizer will be easily dispersed in the compounding species and will be used for a long time without being precipitated after being made into a product. However, when the compatibility of the stabilizer is poor, it will move from the inside to the outside of the article and finally remain on the surface of the article. If the effluent is a powdery solid substance, it is called a frosting; if it is a liquid, it is called "sweating".
In general, certain metal soaps, lubricants and maleic acid organotins are prone to blooming; PVC stabilizers such as phosphites and phosphates also increase the amount of blooming. For metal soaps, metal sprays with less electronegativity are less; aromatic acid roots are less sprayed than fatty acid roots; the longer the carbon chain in fatty acid roots, the more severe the frosting.
(2) Transparency
1. Transparentness of PVC stabilizers and products
Organotin, especially maleic acid esters and mercaptan organotins, is a transparent PVC Stabilizer, mainly in hard transparent products; metal soap has transparency and is used in translucent products; Inorganic lead salts are opaque and can only be used in opaque products.
2. Albinism
If the transparent plastic product is impregnated with water, exposed to the outdoors, or bent, stretched, etc., whitening will occur and the transparency will be lost. The water whitening refers to the phenomenon that the transparent plastic plate is immersed in water for a certain period of time and the white turbidity is opaque; the exposure whitening refers to the phenomenon that the plastic hard plate is placed in the air due to the action of moisture, carbon dioxide, sulfur dioxide and light in the atmosphere; Stress whitening refers to the phenomenon of whitening of creases when plastic products are subjected to mechanical external forces.
3. Fisheye bubbles
When the transparent or translucent plastic sheet is observed against the light, it can be seen that the sheet is covered with transparent or translucent small round particles similar to fish eyes. This is the "fisheye". "Bubble" is caused by a volatile component in the PVC stabilizer or an imbalance in processability.
Novista Group is the professional manufacturer of PVC stabilizers from China.
For more details of PVC stabilizers for pipes/fittings/sheets/boards/profiles, pls email to sales06@novistagroup.com or contact us by WhatsApp (0086 150 6536 1235) / Skype (neil_novista)
