Additives for polyolefins

What are polyolefins? Polyolefin is a type of polymer of olefins. For example, polypropylene or polyethylene. In this article we will highlight our additives for polyolefins for industrial use.

What are Polyolefins?

First of all, we will explain a little bit more about Polyolefins. Polyolefins are thermoplastic resins obtained by separate polymerization or copolymerization of α-olefins. For example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene and some cyclic olefins.

It is a generic term for a class of thermoplastic resins. Due to the abundant raw materials, low prices, easy processing and molding, and excellent comprehensive performance, it is a type of polymer material with the largest output and a wide range of applications.

Secondly, Polyolefins encounter the effects of oxygen and sunlight in nature. This causes the molecular chain and auxiliary of resin to generate free radical R of the polymer. And it will further react with oxygen to form oxidative free radical RO.

Furthermore, the peroxide free radical ROO, the free radical has strong activity and can capture hydrogen from other resin molecular chains and additives to form ROOH hydroperoxide. The unstable hydroperoxide ROOH will be cracked into new free radicals RO and HO.

The two active free radicals further react with oxygen to form new hydroperoxide ROOH. The automatic catalytic oxidation occurs repeatedly, which causes the compounds to break, degrade and crosslink, resulting in molecular chain rupture completely and requires protection. Therefore, it is important to solve the aging problem of polyolefins and create strong parts.

Applications of Polyolefins

The application of anti-aging additives is not a simple addition and accumulation. But an unified system that needs comprehensive consideration. The design of polyolefin anti-aging system should start with the selection of additives for the polymer.

Secondly, selecting the appropriate additives, forming a reasonable formula. At the same time considering the synergy of the additives, the appropriate processing technology and the taboos between the additives to achieve the best status.

Which additives for polyolefins are necessary?

This highly depends on the polymer and application. Examples of polymers are high density polyethylene (HDPE), low density polyethylene (LDPE), Polypropyle (PP) and Polyisobutylene and Polymethylpentene.

UV Absorbers

Especially ultraviolet light can accelerate the frequency of atomic motion and accelerate the degradation of plastics such as oxidation reaction. UV absorbers are indispensable in polyolefins. They can strongly absorb UV rays and convert their energy into harmless thermal energy to release.

UV absorbers include benzotriazoles, benzophenones, salicylates and so on. Omnistab UV 326, UV 329, UV BP 12 (531), UV P, UV 234 are UV absorbers to use as additives for polyolefins, like polyethylene or polypropylene. Click on each product to view the properties and performances. Besides the already known UV absorbers, we are developing a growing number of high quality absorbers under a registered trademark.

Light Stabilizers

A light stabilizer is usually a hindered amine light stabilizer. The hindered amine light stabilizer contains a piperidine group, and a piperidine nitroxide free radical is generated after oxidation.

Piperidine nitroxide free radicals have greater activity and can react with alkyl free radicals and alkoxy free radicals that are degradation product in the resin to produce piperidine alkylamine ethers and piperidyl peroxide amine ethers, stopping the degradation of the resin.

Light stabilizers can continuously self-renew and activate, and can structural capture newly generated free radicals, thereby achieving the purpose of protecting materials. Browse to the Omnistab LS 622, LS 944, LS 119, LS 770, LS B783, which are light stabilizers to use in polyolefins.

Anti oxidants

The role of antioxidants is to inhibit or prolong the oxidation reaction of polymers. The principle is that antioxidants can eliminate peroxide radicals generated during the oxidation reaction, reduce alkoxy or hydrocarbon radicals, and decompose peroxides.

As a result, the oxidation chain reaction is terminated, and the purpose of preventing polymer oxidation is achieved. Recommended antioxidants used in polyolefins are phenols, amines, phosphites and thioesters. Such as Omnistab AN 1010, AN 1076, AN 1098, AN 168 and AN 80.

Frequently asked questions