Chất hóa dẻo được phối trộn vào hỗn hợp cao su, hỗ trợ quá trình gia công. Phần tài liệu dưới đây sẽ giới thiệu về chất hóa dẻo và phân loại chúng theo thành phần hóa học và tính năng.

Plasticizer: Any material (primarily liquid) that is added to a compound to facilitate easier mixing, extruding, molding, and curing through modification of the basic physical properties of the uncured and cured compound (e.g., viscosity, hardness, modulus, low-temperature flex).

Monomeric types: It is common to characterize plasticizers generally as either polymeric or monomeric. For our purposes here, monomerics are all plasticizers (glycol esters, monoesters, diesters, and triesters), which are not polymeric. Viscosities range from 4 to 400 cps.

Polymeric types: This group is technically comprised of polyesters with viscosities from 400 to 200,000 cps. To create polyester, a glycol rather than an alcohol is reacted with a fatty acid. For purposes of this chapter we exclude the very high polymers used as polymeric plasticizers such as Nipol 1312, a low-molecular weight NBR elastomer.

Synthetic plasticizers: These are chemically reacted, man-made, from highly specified components to form a plasticizer with consistently reproducible properties. Esters comprise the major portion of this category.

Low-temperature improvement: This is achieved through the use of plasticizers primarily related to their molecular weight as measured by viscosity. A rating system has been applied to a number of plasticizers in Table 12.1. Compatibility is also a factor to be considered, hence the ratings in both polar and semipolar elastomers is given.

High-temperature performance: It is also related to the molecular weight of the plasticizer as measured by volatility, as may be seen in Table 12.2. The relative solubility of a number of plasticizers is also given, which relates to their extractability in various fluids in service. Both of these factors must be considered when designing a specialty elastomer compound.

Trích đăng từ sách Handbook of Specialty Elastomers, Robert C. Klingender, CRC Press, 2008, trang 389


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