Study on Transparent Poly(propylene) Nucleated by the 'in Situ' Reaction Products of Dehydroabietic Acid and Sodium Stearate

摘要

Dehydroabietic acid (DHA), sodium stearate (NaSt), DHA/NaSt (1/1 wt/wt) mixture, the reaction products of DHA/NaSt (1/1 wt/wt) mixture after heating at 220 degrees C for 10 min and sodium dehydroabietate (DHAA-Na) were qualitatively analyzed by Fourier transform infrared spectrometry (FTIR) and wide angle X-ray diffractometry (WAXD). The crystallization behavior, spherulitic morphology, optical and mechanical properties of iPP samples nucleated by DHA, NaSt, DHA/NaSt (1/1 wt/wt) mixture, and DHAA-Na under the same concentration (0.3 wt %) were investigated by differential scanning calorimetry (DSC), polarized light microscope (PLM), optical and mechanical measurements. The results showed that an "in situ" reaction occurred between DHA and NaSt, and an effective transparent nucleating agent (DHAA-Na) was produced during the melting blending of iPP and DHA/NaSt (1/1 wt/wt) mixture in the twin screw extruder. The crystallization onset and peak temperatures, the gloss and the mechanical properties were improved markedly; the crystallization half-time, the spherulitic size, and the haze were reduced substantially when iPP samples are nucleated by DHA/NaSt (1/1 wt/wt) mixture. The optimum composition ratio of DHA/NaSt should be kept at approximate to 1/1 wt/wt and above 0.4 wt %/0.4 wt %. The DHA/NaSt bi-component nucleator was effective for iPP with different MFR values. (c) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 2436-2444, 2009