Transparency Of PVC Stabilizer, Whitening Phenomenon

People always hope that the PVC stabilizer is easy to disperse in the compound species, and it can be used for a long time without precipitation after being made into a product. However, when the compatibility of the stabilizer is poor, it will migrate from the inside of the article to the outer surface, and finally stay on the surface of the article. If the spray is a powdery solid substance, it is called frosting; if the spray is liquid, it is called "sweat"

Generally speaking, some metal soaps, lubricants and organic tin maleate are easy to cause blooming; PVC stabilizers such as phosphite and phosphate ester will also increase blooming. For metal soaps, the metal with less electronegativity sprays less; aromatic acid radicals have less blooming than fatty acid roots; the longer the carbon chain in the fatty acid roots, the more serious the blooming.

transparency

1. Transparency of PVC stabilizers and products

Organotin, especially maleate and thiol organotin, is a kind of PVC stabilizer with good transparency, mainly used in hard transparent products; metal soaps have transparency and are mostly used in translucent products; Inorganic lead salts are opaque and can only be used in opaque products.

2. Whitening phenomenon

If transparent plastic products are soaked in water, exposed to the sun, or bent or stretched, they will whiten and lose transparency. Water immersion whitening refers to the phenomenon of white turbidity and opacity of the transparent plastic board immersed in water for a certain period of time; exposure whitening refers to the phenomenon that the plastic hard board 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 the crease when plastic products are subjected to mechanical external force.

3. Fish eye bubbles

When the transparent or translucent plastic sheet is observed against the light, it can be seen that transparent or translucent small round particles similar to fisheyes are mixed in the sheet, which is "fisheye". "Bubble" is caused by volatile components in the PVC stabilizer or an imbalance in processability