Dupont Neoprene GW

In the industrial application of chloroprene rubber, the processing performance and physical properties of the rubber vary significantly depending on the type of regulator used during the polymerization process. CR121 and CR322 are two highly representative general-purpose chloroprene rubbers. This article will analyze the specific differences between sulfur-modified (CR121) and mixed-modified (CR322) chloroprene rubber from three dimensions: technical characteristics, processing performance, and application selection, providing professional reference for production and processing.   1. Comparison of Technical Characteristics and Performance Indicators of CR121 and CR322 CR121 belongs to the classic sulfur-modified chloroprene polymer. This type of rubber uses sulfur as a regulator during polymerization, and its molecular chain contains a certain amount of sulfur segments, which gives it good tear resistance and flexural resistance. In terms of physical form, CR121 is a yellowish-white or light brown block, with a density of 1.23. From a performance standard perspective, the crystallization rate of CR121 is at a medium-to-low level, its tensile strength is not less than 24 MPa, and its elongation at break is excellent, usually above 900%. In industry standards, CR121 is similar to Dupont Neoprene GNA and Denka Chloroprene PM-40.     In contrast, CR322 is a chloroprene polymer that uses sulfur and diisopropyl xanthate disulfide as mixed regulators. This "mixed modification" mode aims to retain the advantages of sulfur-modified types while introducing xanthate to improve the stability and processing flexibility of the rubber compound. CR322 is also a yellowish-white or light brown block, with a density of 1.23, and its crystallization rate is also medium-to-low. In terms of core physical indicators, the tensile strength of CR322 is slightly higher than that of CR121, reaching over 26 MPa, but the elongation at break is slightly lower, approximately 800%. This model is similar in performance to Dupont Neoprene GW. In terms of Mooney viscosity, both offer subdivided grades to meet different needs. CR121 includes specifications such as CR1211 (20-40), CR1212 (41-60), and CR1213 (61-75). CR322 correspondingly offers grades such as CR3221 (25-40), CR3222 (41-60), and CR3223 (61-80). Both exhibit consistent Mooney scorch time, requiring more than 30 minutes, ensuring good thermal stability.   2. Analysis of Differences in Processing Performance and Physical Strength Although CR121 and CR322 are similar in some basic physical indicators, the actual production experience brought about by "mixed modification" and "pure sulfur modification" is quite different. The core advantage of CR121 lies in its extremely high elastic reserve and excellent dynamic fatigue resistance. Due to its elongation at break reaching 900%, under working conditions requiring significant stretching or frequent bending, the molecular chains of CR121 exhibit stronger fatigue resistance. However, the disadvantage of the pure sulfur modified type is that it requires stricter processing techniques, especially during mixing and extrusion, where the control of rubber flow and viscosity requires extensive experience. CR322 is designed to compensate for the shortcomings of traditional sulfur-modified types. Official technical data shows that CR322 has better processing performance than pure sulfur-modified rubber. In actual production, due to the introduction of xanthate modifiers, CR322 has better plasticizing performance and more stable molding fluidity. In addition, CR322's tear strength is particularly outstanding, which matches its tensile strength of 26 MPa. This means that in situations involving sharp objects scratching or strong tearing, CR322 can provide more robust structural protection than CR121. Furthermore, in terms of storage stability, both are basically the same. From the date of manufacture, they can be stored for one year below 20℃ and for six months below 30℃. However, in extreme climates or complex warehouse environments, the mixed-modified CR322 often exhibits better resistance to physical property degradation than the pure sulfur type, thanks to its diversified molecular structure improvements.   3. Typical Application Scenarios and Selection Guidelines The choice between CR121 and CR322 depends primarily on the dynamic load requirements and manufacturing process of the final product. ♠ Applicable Scenarios for CR121: Due to its excellent flexural resistance and high elongation, CR121 is the preferred choice for manufacturing high-performance transmission products. Industrial belts: Including conveyor belts, multi-ribbed belts, V-belts, and synchronous belts. In these applications, the rubber is repeatedly bent around pulleys, and the excellent bending fatigue resistance of CR121 significantly extends the belt's service life. Heavy-duty cable sheathing: Especially for mining cable sheathing and other applications requiring frequent movement and dragging, the tear resistance and flexibility of CR121 provide reliable physical protection. ♠ Applicable Scenarios for CR322: Thanks to its higher physical strength and optimized processing rheology, CR322 performs better in structural rubber components. Hose products: CR322 is commonly used in the manufacture of various chemical-resistant and weather-resistant industrial hoses. Its high tear strength ensures that the hose body is less prone to structural failure under pressure or external abrasion. Complex molded parts: Due to its superior processing performance compared to sulfur-modified types, for rubber parts with complex shapes and high mold cavity filling requirements, using CR322 can effectively reduce the scrap rate and improve production efficiency. Specialty tapes: In the manufacture of tapes requiring extremely high strength, CR322, with its tensile strength advantage of 26 MPa, can provide stronger load-bearing capacity.   Summary: If you are pursuing ultimate flexibility and dynamic fatigue resistance (such as synchronous belts and V-belts), CR121 is the technical "gold standard." If your production process requires high fluidity and moldability of the rubber compound, or if your product requires higher tensile strength and tear protection (such as pressure hoses and high-strength seals), then the mixed-modified CR322 will be a more efficient and cost-effective choice.   In practical applications, users also need to make fine adjustments based on specific grades (such as different Mooney viscosity levels). For example, CR1211 is suitable for processes requiring good flowability, while CR3223 is suitable for heavy industrial applications that demand higher hardness and tensile strength. Understanding the chemical modification mechanisms of these two materials is crucial for improving the quality of rubber products.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com