What is the difference between natural latex and artificial latex?

Source of natural latex

Natural latex exists in the latex tubes between the cork and phloem of Hevea brasiliensis. The latex tubes are in a mesh shape. When tapping rubber, use a knife to gently cut the epidermis, and the latex will flow out from the knife edge, from more to less, and gradually stop, and the knife edge will condense.

Composition of natural latex

When natural latex is obtained from the tree, it is a milky white or light yellow milk-like liquid. There are many spherules in it, which are composed of rubber hydrocarbons, proteins, and acetone extracts.

In addition to the spherules in natural latex, there are also substances such as ash and water.

The content of protein in latex is generally about 2~2.5%. This is an extremely complex colloidal substance. It is a macromolecular organic compound composed of carbon, hydrogen, oxygen, helium and a small amount of sulfur, phosphorus, iron and other elements. It prevents oxidation of the spherules in the latex and makes the latex or a stable dispersion.

The content of acetone extract in latex is generally about 2%. Its function is basically the same as that of protein, except that it is more useful for latex than protein.

The water content in latex is generally about 55%, which is the dispersion medium for spherical particles, minerals, etc. in latex. When making latex products, it is often used as a foaming agent to make porous latex products.

The general content of ash in latex is about 0.5%.

Water-soluble substances mainly refer to various sugars. Its content is generally 1.5%~4.2%. Its presence can affect the high insulation of the product.

In addition, latex contains a small amount of natural antioxidants and enzymes. The former prevents the aging of raw rubber; the latter easily ferments latex, reduces the pH value of latex, and makes the latex naturally coagulate.

Uses of natural latex Natural latex can be directly made into various latex bedding products, and is also the raw material for making natural rubber. It can also be used to make various film products, such as gloves, balloons, etc.

Composition of synthetic latex

For a long time, synthetic latex is composed of a mixture of artificial latex and natural latex, and is classified according to the proportion of artificial latex and natural latex. Chloroprene latex was used first, but it has now been eliminated. The most widely used one is styrene-butadiene latex (now mostly called styrene-butadiene rubber).

Styrene-butadiene rubber, also known as polystyrene butadiene copolymer, abbreviated in English as SBR, is a petroleum extract.

Uses of synthetic latex Tire tread, tread, conveyor belt, hose, molded and extruded products, road paving asphalt, etc.

Production method of synthetic latex

Using butadiene and styrene as the main monomers, with other auxiliary chemical raw materials, under certain process conditions, styrene-butadiene slurry is first generated by emulsion polymerization, and after removing the unconverted monomers in the slurry, the product rubber is produced through processes such as coagulation and drying.

Performance comparison of the two

Compare the performance of SBR latex, natural latex, and various sponge rubbers made by adding different amounts of fillers to these latexes.

1. The breaking strength and elongation of synthetic latex products are lower than those of natural latex.

2. The compression deformation of synthetic latex products is smaller than that of natural latex products regardless of the compression size.

3. The elasticity of synthetic latex products is lower than that of natural latex products.

In other words, the performance of synthetic latex products is generally worse than that of natural latex products.