| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 봄 (04/14 ~ 04/15, 전경련회관) |
| 권호 | 30권 1호, p.580 |
| 발표분야 | 복합재료 |
| 제목 | Effect of Dispersed Silicates on the Spherulite Morphology for Maleated Polypropylene/Clay Nanocomposites. |
| 초록 | Recently, it has been reported that polar groups such as maleic anhydride can be grafted onto PP to enhance the compatibility between clays and PP chains during melt blending. PP/clay nanocomposites, however, has mainly been focused on the nanocomposite structures and their relationship with physical and mechanical properties, and only a few studies have been geared toward the effect of nanocomposite structure on the crystallization behavior of PP. In present study, the isothermal crystallization behavior of maleic anhydride grafted polypropylene (mPP) in hybrids with unmodified or organically modified montmorillonite (MMT) has been investigated by using time-resolved wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The effect of silicate dispersion on the spherulites morphology of mPP was also studied by POM measurements. Average spherulite sizes and number density were obtained from the POM images and monitored as a function of time. WAXS and transmission electron microscopy (TEM) showed that the mPP/unmodified MMT hybrids formed macrophase-separated mixtures rather than intercalated nanocomposites, while mPP/organically layered silicate (OLS) hybrids formed exfoliated nanocomposites. The crystallization rate of mPP/unmodified silicate hybrids became faster with the MMT addition due to the fact that agglomerated silicates in the mPP matrix act as nucleating agents, as confirmed by POM. On the other hand, the crystallization rate as well as the growth rate of spherulites of the mPP/OLS hybrids was slowed down with the OLS addition. This retardation of the mPP crystallization is probably due to the presence of well-dispersed exfoliated silicates as diffusion and/or displacement barriers for crystallization. |
| 저자 | 김백진1, 이승헌2, 차국헌3 |
| 소속 | 1한국생산기술(연), 2LG화학/기술(연), 3서울대 |
| 키워드 | crystallization; morphology; polarized optical microscopy; spherulite growth |
