Nylon nucleating agent

Names Acrylonitrile-styrene copolymer, Elvaloy Nylon Nucleating Agent Polywax Silbyk CAS 9003-54-7... 

In addition to the nucleating agents discussed in Section 18.4, many other materials have been found to be effective. Whilst the nylons may be self-nucleating, partieularly if there is some unmelted crystal structure, seeding with higher melting point polymers can be effective. Thus nylon 66 and poly(ethylene terephthalate) are reported to be especially attractive for nylon 6. 

In the PP-PA system, the DSC thermograms showed two peaks corresponding to nylon and PP. For the compatibilized system the crystallization peak of nylon remains unaltered, while that of PP shifted toward a higher temperature in the case of PPacr, and for PPmal, the shift was to lower temperatures (Fig. 1). This may be due to the fact that PPacr was acting as the nucleating agent. The average crystallinity of the blend was also decreased by the incorporation of compatibilizer. The mechanical properties of these blends was improved by the addition of PPmal and PPacr as compatibilizers (Table 1). 

Nylon, nucleated n. A nylon polymerized in the presence of a nucleating agent, e.g., about 0.1% of finely dispersed silica, which promotes the growth of spherulites and controls their number, type, and size. Nucleated nylons have higher tensile strength, flexural modulus, abrasion, resistance, and hardness, but lower impact strength and elongation than their unnucleated counterparts. 

Sodium benzoate. Sodium benzoate is an inexpensive traditional nucleating agent used predominantly in nylon and PP homopolymer. Sodium benzoate has full FDA approval in PP and is used in food applications and pharmaceutical synthesis. Typical use levels of sodium benzoate as a nucleating agent in PP are lower than the sorbitols. The major application is in injection-molded packaging closures. 

Nucleating agents are typically added postreactor and are used primarily in injection molding application. However, they can also be used in other thermoplastic processing applications. They are generally incorporated into materials such as nylon, polypropylene, crystalline polyethylene terephthalate (PET), and other thermoplastic PET molding compounds at use levels typically below 1 percent. Incorporation is done in several ways including powder mixtures, suspensions, solutions, or in the form of a masterbatch. 

M0S2 is really only effective in nylon, where it acts as a nucleating agent, promoting the growth of fine crystalline structure at the surface of the moulding. Nylons are prone to form a skin of amorphous polymer, as they freeze rapidly at the surface this is less wear resistant than the crystalline structure. 

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