A quantitative estimation of the extent of compatibilization in heterogeneous polymer blends using their heat capacity increment at the glass transition
✍ Scribed by Y. X. Pang; D. M. Jia; H. J. Hu; D. J. Hourston; M. Song
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 390 KB
- Volume
- 74
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
In this paper a new method based on the determination of heat capacity increment at the glass transition (⌬Cp) is presented to quantify the effectiveness of compatibilizers for immiscible polymer blends. In order to show the validity of the method, two immiscible blends, polypropylene-poly(ethylene terephthalate) (PP-PET) and PP-polyamide-6,6 (PP-PA66), and two compatibilizers, N, N-dihydroxyethyl monomaleic amide-grafted PP (g-PP) alone and together with a phenolic resin (PR), were investigated. Scanning electron microscopy (SEM) observations prove that the two compatibilizer systems are both effective for compatibilizing the blends, and the combined use of g-PP and PR is more effective than g-PP alone. Modulated-temperature differential-scanning calorimetry (M-TDSC) determinations reveal that the ⌬Cp varies with the extent of compatibilization. For the uncompatibilized blends, the ⌬Cp for the PET component in PP-PET or for the PA66 component in PP-PA66 was found to be almost unchanged. After compatibilization these quantities become smaller. Also, the combined use of g-PP and PR results in the smallest ⌬Cp values for both blends. This ⌬Cp change with different compatibilizers is in very good agreement with the corresponding morphological variation observed by SEM. Thus, ⌬Cp can be taken as a new parameter for quantifying the extent of compatibilization, since it is a direct measure of interfacial content.