In situ compatibilization

Those involving the use of functionalized blend components that produce in situ compatibilizing interchain copolymers some common reactive functionalities include carboxyl, epoxy, isocyanate, and anhydride, etc. 

Santra RN et al. (1993) In-situ compatibilization of low-density polyethylene and polydimethylsiloxane rubber blends using ethylene-methyl acrylate copolymer as a chemical compatibilizer. J Appl Poly Sci 49(7) 1145-1158... 

An attractive route to compatibilize thermoplastic blends, hke polyolehn-PS, is the Friedel-Crafts ahcylahon (F-C). By this reaction, a hydrocarbon chain can be chemically bonded to the PS benzene ring through an aromatic electrophilic substitution. The graft copolymer formed (polyolefin-g-PS), situated at the interphase, will behave as an in situ compatibilizer. The present work discusses the binary (PE/PS, PP/PS) and ternary (PE/PP/PS) blends compatibihzation by F-C reactions. Detailed smdies were performed on the F-C and side reaction characterization, blend morphological aspects, and final mechanical properties. 

S. G. Cottis and K. M. Natarajan. In situ compatibilization of ppe/polyethyl-ene copolymer blends. US Patent 5 286 793, assigned to Jstituto Guido Done-gani (Milan, IT) Enichem America, Inc. (Monmouth Junction, NJ), February 15, 1994. 

Gopakumar et al. [10] reported the in situ compatibilization of poly(phenylene sulfide) (PPS)/wholly aromatic thermotropic liquid crystalline polymer (TLCP) Vectra A950 blends by reactive extrusion. The authors prepared the in situ compatibilized PPS/TLCP blends in a twin-screw extruder by reactive blending of PPS and TLCP in the presence of dicarboxyl-terminated poly(phenylene sulfide) (DCTPPS). Block copolymer was formed during reactive blending, by transesterification reaction between carboxyl... 

In Situ Compatibilization of Polymer Blends via Y or E-Beam Radiation... 

Lin and Isayev (2006) prepared blends of PA-6 and PP by treatment with high-intensity ultrasound during extrusion. Mechanical properties, crystallinity, and morphology were investigated. The competition between polymer degradation and partial in situ compatibilization was assessed. 

HDPE/PA6 blends with HDPE-g-MAH as a compatibilizCT Thermal properties were studied using TGA and DSC Thermal behavior of in situ compatibilized blcatds was studied using TGA and DSC Hsu et al. 2001... 

In situ compatibilization is based on a specific chemical reaction between two functional polymeric components during blending, and thus is also known as reactive blending [5, 17]. Scheme 7.1 exemplifies reactions that take place at the interface between reactive functional polymers. Because the chemical reaction takes place within the interphase, the copolymer is produced in situ, where it is necessary, with segments from the two homopolymers. The process needs (i) sufficient... 

Ch Tselios, D. Bikiaris, P. Savidis, C. Panayiotou, A. Larena, Glass-fiber reinforcement of in situ compatibilized polypropylene/polyethylene blends. Journal of Materials Science 34 (2) (1999) 385-394. 

Similarly, Saeed and Park [65] synthesized PA 6-multiwaIl carbon nanotubes (MWNTs) nanocomposites via the in-situ polymerization technique, using pristine and COOH-functionalized MWNTs. Based on SEM morphology analysis, it was shown that the COOH-functionalized MWNTs were better dispersed in the PA 6 matrix than the pristine ones, owing to the covalent attachment of PA 6 molecular chains to the side walls of MWNTs, which could act as in-situ compatibilizers in the nanocomposites and enhance the dispersion of MWNTs. In terms of physical properties, the crystallization of nanocomposites was increased compared to that of virgin PA 6, due to the nucleation effect of MWNTs, while the thermal stability under nitrogen of the nanocomposites was superior. Turning to the mechanical properties of the nanocomposites, the uniformly dispersed MWNTs improved the tensile properties because of the reinforcement effect. 

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