Ternary polymer compatibilization

Lecourtier, J. Lafuma, F. Quivoron, C., "Study of Polymer Compatibilization in Solution through Polymer/ Polymer Interactions Ternary Systems Polyethylene oxide)/ Styrene-Methacrylic Acid Copolymers/Solvent," Makromol. Chem., 183,2021 (1982). 

Morphology of the uncompatibilized (a, a a") and compatibilized (b, b b") ternary poly-propylene/polystyrene/polyamide (PP/PS/PA6) (70/15/15) blends (a,b) cryofractured surface, (a, b ) cryofractured and PS phase extracted using tetrahydrofuran (THF), (a", b") cryofractured and PA6 phase extracted using HCOOH. (Reproduced from Wang, D., Li, Y., Xie, X.-M., and Guo, B.-H. 2011. Compatibilization and morphology development of immiscible ternary polymer blends. Polymer 52 191-200 with permission from Elsevier.)... 

In ternary nanocomposites, compatibilizers have been mostly used to improve the adhesion at the polymer/filler interface rather than to modify the polymer/elastomer interface. Mishra et al. [80] compounded PP/EPDM/organoclay (75/25/5 wt%) and added PP-g-MA (1 wt% MA) as a compatibilizer with a clay/PP- -MA ratio of 1/3. They characterized the interlayer spacing of the clay platelets by XRD and observed that it increased from 3.4 to 4.3 nm for systems without and with compatibilizer. This was attributed to a better diffusion of the PP-g-MA chains inside the interlayer spacing thanks to their functional groups. Numerous other authors prepared and characterized ternary composites with a compatibilizer. Examples include Lim et al. [81] and Lee et al. [5] on PP/PP- -MA/POE/ organoclay systems, Mehta et al. [23] on PP/PP-g-MA/EPR/organoclay systems, and Liu and Kontopoulou [24,45] on PP/PP-g-MA/ethylene-octene copolymer/silica composites. It should be noted that the compatibilizer itself may affect the properties of the matrix... 

The molecular dynamics of ternary polymer blends of PP/PA6/acrylonitrile butadiene styrene copolymer (ABS) in the presence of compatibilizers and multiwall carbon nanotubes (MWNTs) was investigated using DRS [69]. The relaxation time of the PA6 chains was found to have increased significantly when small amounts of compatibilizers (PP-g-MA) or styrene maleic anhydride (SMA) were added. The variation in relaxation time was found to depend heavily on the com-patibilizer efficiency. The variation in relaxation time for PA6 in the presence of 1 wt% MWNTs in the respective ternary blends also followed a similar trend however, the extent of mobility of the PA6 phase was influenced by the state of dispersion of MWNTs in the corresponding blends. 

The morphology of ternary component polymer blends was shown to be related to the interfacial forces involving the components by Hobbs et al. [235]. The analysis of the interfacial forces is relevant to the concept of compatibilization by a ternary polymer additive to a binary blend. If a polymer can be chosen that exhibits good interfadal adhesion between the binary components and concentrates at the interface, improved properties can be obtained. The governing equation for determination of the resultant morphology of the ternary blend is ... 

Ternary blends that comprise two immiscible polymers and a copolymer are of a particular interest. They not only represent an ideal model for studying compatibilization of polymer blends, but also they have found direct commercial applications. Phase diagram information can be found in reviews by Ajji and Utracki [1996, 1997] and in Chapter 2 in this Handbook. 

A key paper involving the experimental interfacial aspects of polymer blends discussed the blends of more than two components wherein a polymeric constituent will concentrate at the interface between two of the blend constituents [Hobbs et al., 1988]. Employing the concepts of interfacial relationships, it was shown that a ternary component can concentrate at the interface between the other constituents and allow for compatibilization of dissimilar and incompatible components. As an example, it was shown that in the ternary blend of PMMA/PC/PBT, PC encapsulates PMMA as a dispersed phase in a matrix of PBT. PC, which exhibits partial miscibility with PMMA and PBT thus compatibil-izes PMMA/PBT blends. 

TERNARY BLENDS OF POLYOLEFINS WITH OTHER POLYMERS AND COMPATIBILIZING AGENTS... 

There are multiple techniques under development to stabilize the bulk heterojunction and consequently improve performance stability the use of ternary blends with compatibilizers, such as, block copolymers, amorphous fullerene derivatives, high glass transition temperature polymers, thermos-cleavable polymers, specifically designed donor-acceptor systems with enhanced interactions, functionalized side chains on the polymer and cross-linkable materials (Mulherin et al., 2011). The cross-linking materials... 

Source Elmaghor, E, Zhang, L., Li, H., Recycling of high density polyethylene/ poly(vinyl chloride)/polystyrene ternary mixture with the aid of high energy radiation and compatibilizers. Journal cf Applied Polymer Science 2003,88,2756-2762. With permission. 

In particular, a microporous poly(/-lactide) (PLLA) composition can be prepared using poly(styrene) (PS) and as compatibilizer a copolymer from a lactide and styrene. Binary blends and compatibilized ternary blends are prepared by melt mixing the polymers and copolymer in a Brabender internal mixer with roller blades, under a constant high flow of dry nitrogen. Dry nitrogen is required to avoid a dramatic melt degradation of the PLLA. Prior to blending, PLLA and PS are dried for 48 /z in a vacuum oven at 70°C. 

Ternary blends containing LCPs also show an attractive approach to the development of reinforced systems. The differences between ternary polyblends and polyblends with a third component (a compatibilizer) added are that in the latter, usually the third components is a pre-made compound (or polymer) and its fraction in compatibilized blends is less than 10 wt%. The third polymer used in ternary blends is an as-received commercial product, and its content in ternary blends can be changed for tailoring the properties of blends. 

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