Sulfur-adjusted neoprene is also known as a general-purpose or G-type. Because it is used in the synthesis of sulfur and autumn lamb to make the adjustment, so the molecular chain has many sulfur bonds. The non-sulfur type is also called W type, the manufacture of sulfur alcohol as a regulator in the molecular chain does not contain sulfur.
The microstructure of neoprene is mainly decided by polymerization temperature, when the polymerization temperature is low, there are many trans-1,4-structure, high molecular regularity, high crystallinity, high molecular weight, and low molecular weight content.
The crystallization ability of neoprene is higher than that of natural rubber, BR and butyl rubber. Because of its macromolecular chain mainly vanadium is 1,4-structure, like Gutapo Gum, is the 1,4-structure crystallization. The degree of crystallization of rubber processing and applications have an important impact, generally not vulcanized rubber in the long-term storage, will produce crystallization, increase the hardness. Vulcanized rubber in the -5~21℃ can also produce crystallization, 0 ℃ below quickly produce crystallization, temperature will be reversible melting crystal. Depending on the use, the polymerization conditions can be adjusted to synthesize different crystallization ability of rubber. The crystallization ability of domestic neoprene is divided into four grades: micro, low, medium and high, and five grades abroad: small, medium, medium, large and great. The crystallization ability of micro and small is generally the copolymer of Chloroprene and other monomers, the sulfur-regulating type has low crystallization ability, and the crystallization ability of non sulfur type is medium. CR2481, CR2482, AC, AD and other adhesive-type crystallization ability is high.
The double bond and the chlorine atom in the chloroprene rubber structure are not lively enough to react easily. The reaction activity, oxidation activity and ozonation reaction activity were lower than that of natural rubber, SBR and NBR. It cannot be cured by a general sulfur sulfide system. and anti-aging, ozone-resistant aging is much better than the general unsaturated rubber.
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