Compatibilization, polymer

Commercial thermoplastics are the engineering materials containing two or more compatibilized polymers that are chemically bounded in a way that creates a controlled and stable morphology with a unified thermodynamic profile. In view of multiplicity and contradictory requirements of various properties for most of the applications, almost all the commercial PBAs are made of two or more thermoplastics, elastomeric modifiers along with a series of compatibilizers with modifiers compounded together. A considerable number of blends have been appearing in the market regularly, some of which are listed in Table 9. 

Two procedures were used to prepare compatibilized polymer-filler composites ... 

Well-dispersed and long-term stable carbon nanotubes/polyol dispersions can also be prepared by a mechanochemical approach with the aid of a dispersing agent (Tang and Xu, 1999). Good dispersion of CNTs in polymer matrix can be achieved by means of high-power dispersion, compatibilizer, polymer-assisted blending, and surfactants (Cochet et al., 2001). 

Xu S, Chen B, Tang T, Huang B. Syndiotactic polystyrene/thermoplastic polyurethane blends using poly(styrene-l)-4-vinylpyridine) diblock copolymer as a compatibilizer. Polymer 1999 40 3399-3406. 

Compatibilizer Polymers. ABS copolymers that are functionalized may act as a compatibilizer for other polymer blends. These types are grafted in the same way as polymers dealt with above. 

Tol RT, Groeninckx G, Vinckier I, Moldenaers P, Mewis J (2004) Phase morphology and stability of co-continuous (PPE/PS)/PA6 and PS/PA6 blends effect of rheology and reactive compatibilization. Polymer 45 2587-2601... 

Macosko and his co-workers have estimated Si for a number of immiscible un-compatibilized polymer pairs in the Table 11.1. 

Block copolymers in selective solvents exhibit a remarkable capacity to self-assemble into a great variety of micellar structures. The final morphology depends on the molecular architecture, tlie block composition, and the affinity of the solvent for the different blocks. The solvophobic blocks constitute the core of the micelles, while the soluble blocks form a soft and deformable corona (Fig. Id). Because of this architecture, micelles are partially Impenetrable, just like colloids, but at the same time inherently soft and deformable like polymers. Most of their properties result from this subtle interplay between colloid-like and polymer-like features. In applications, micelles are used to solubilize in solvents otherwise insoluble compounds, to compatibilize polymer blends, to stabilize colloidal particles, and to control tire rheology of complex fluids in various formulations. A rich literature describes the phase behavior, the structure, the dynamics, and the applications of block-copolymer micelles both in aqueous and organic solvents [65-67],... 

Riemann RE, Cantow HJ, Friedrich Chr. Interpretation of a new interface-governed relaxation process in compatibilized polymer blends. Macromolecules 1997 30 5476-5484. 

Block and graft copolymers possessing segments with chemical structures which are the same as those of the polymers to be blended are effective com-patibilizing agents. Thus, an AB block or graft copolymer compatibilizes polymers A and B (see Diagram 1). 

Extrapolation of the concept of the compatibility of polymers with different structures but similar solubility parameters to the construction of effective compatibilizing agents leads to the use of block and graft copolymers having segments with suitable solubility parameters to compatibilize polymers which differ both in structure and solubility parameter. Thus, an AB block or graft copolymer compatibilizes polymers A and C when C has a solubility parameter similar to that of B, polymers D and B when D has a solubility parameter similar to that of A, and polymers C and D when the solubility parameter of C is similar to that of B, and D has a solubility parameter similar to that of A. 

Immiscible, compatibilized polymer blend with modified interface and morphology. 

It is also not the purpose of this chapter to summarize examples of compatible polymer blends formed in a solution step involving dissolution of the polymer components. In some cases such blends are only pseudo-stable , since they may not have been processed above the Tg of one or both of the components. Also, mixing in solution followed by devolatilization is rarely economical for practice in industry, particularly since many commercially important compatibilized polymer blends comprise at least one semicrystalline component e.g., PA) which is poorly soluble in common solvents. There are included in the Tables a small number of examples of solution blended polymer blends when these complement similar examples prepared by melt processing. 

It is also not the purpose of this chapter to describe examples of compatibilized polymer blends formed by polymerization of a monomer in the presence of a second polymer. In these cases the growing polymer chain reacts with functionality on the second polymer to form a... 

The problem of controlling the redistribution process does not stop at the manufacturing stage. After a compatibilized polymer blend leaves the manufacturer, it undergoes further thermal histories such as molding or paint-oven drying at the processing facilities of the final user. Continued redistribution reaction in the hands of a final user may cause deterioration and nonreproducibility in blend properties. 

Brief reviews covering redistribution reactions in polyester and in polycarbonate binary blends have been prepared by Porter et al. [1989] and Porter and Wang [1992]. Selected references for redistribution processes in PEST/PEST blends are listed in Table 5.7. Early studies of these processes focused on measuring the extent of redistribution under specific processing conditions rather than on producing compatibilized polymer blends with an attractive balance of properties. A number of more recent studies have reported the limits of miscibility for certain melt-mixed polyester pairs in the absence of transesterification — see for example the NMR study of PC/PET blends [Abis et al., 1994]. 

The interphase thickness depends on the miscibility of the polymeric component as well as on the compatibilization. For uncompatibilized binary, strongly immiscible systems, the interphase thickness Al - 2 nm. The thickest interphase has been observed for reactively compatibilized polymer alloys Al = 65 nm. For most blends, the interphase thickness is in between these two limits. The importance on the interphase can be appreciated noting that its volume will be the same as that of the dispersed phase when the drop diameter (without interphase) is about 500 nm. It is noteworthy that in most commercial polymer alloys the drop diameter is about five times smaller, making the importance of the interphase much greater. 

Compatibilized Polymer Blends. Immiscible blends in which the microstructure and physical properties can be stabilized by adding surface-active species called compatibilizers. These compatibiliz-ers will influence various morphological processes, such as deformation, breakup, and coalescence of droplets. 

Thus, from this data, it appears that both the alternating and diblock copolymers are the most efficient at compatibilizing polymer blends. Unfortunately, these two copolymers are also the most difficult to realize and therefore, this is of little use from a commercial standpoint. It is interesting that the alternating copolymer may rival the diblock copolymer as a compatibilizer and this possibility is currently under investigation in our laboratory. Within the random copolymers (Px = 0.5, 1.0, and 1.5), these results suggest that the blocky structure is much better at interacting with the homopolymers than the alt-ran structure, and thus should be a more effective interfacial modifier. 

Dextrol OC-45N Dextrol OC-50 Dextrol OC-65K Dextrol OC-78N Dextrol OC-180 Dextrol OC-1025 Dextrol OC-1525 Dextrol OC-2225 Dextrol OC-4025 Dextrol OC-6025 Dextrol OC-7525 Strodex MRK-98 Strodex PK-OVOC Strodex PK-80A Strodex PK-90 Strodex PK-95G Strodex PK-95H Strodex PSK-28 Strodex SFK-50D compatibilizer, pigment dispersions Methylpropanedbl, MPDiol Glycol compatibilizer, polymer blends paper coatings... 

Ethylene/MA copolymer compatibilizer, polymers Ethylene/MA copolymer compatibilizer, polymers Incompatible e-Caprolactone homopolymer compatibilizer, PP/FVOH Polybond 3002 Polybond 3150 compatibilizer, PP/polyamIde Polybond 3002 Polybond 3150 compatibilizer, PVB Resamin HF 480 compatibilizer, PVC copolymers Resamin HF 480 compatibilizer, silicones Phenyl trimethicone compatibilizer, sidisliales Ethylene/MA copolymer compatibilizer, therirnplastic backbone coating resins Resamii HF 480... 

PEG-4 diheptanoate compatibilizer, personal care Methylpropanediol compatibilizer, pigment dispersions Methylpropanediol compatibilizer, polymer alloys Propylene/MA copolymer compatibilizer, polymer blends Propylene/MA copolymer compatibilizer, rubber C20-40 pareth-10 compatibilizer, silicone/organic Cetearyl methicone compatibilizer, silicones Phenyl trimethicone compatibilizer, UV coatings Cetoleth-5... 

BiMaris D, Prinos J, Koutsopoulos K, Vouroutzis N, Pavlidou E, Frangis N et al (1998) LDPE/ plasticized starch blends containing PE-g-MA copolymer as compatibilizer. Polym Degrad Stab 59 287-291... 

The components are then melt blended. Thereby a compatibilized polymer blend is prepared, wherein the pol5nners (A) and (B) have an essentially continuous morphology. At cooling the blend to room temperature, retaining its morphology should be retained. 

Mishra, J. K., Hwang, K.-J., and Ha, C.-S. 2005. Preparation, mechanical and rheological properties of a thermoplastic polyolefin (TPO)/organoclay nanocomposite with reference to the effect of maleic anhydride modified polypropylene as a compatibilizer. Polymer 46 1995-2002. 

Multiphase polymer blends are of major economic importance in the polymer industry. The most common examples involve the impact modification of a thermoplastic by the microdispersion of a rubber into a brittle polymer matrix. Most commercial blends consist of two polymers combined with small amounts of a third, compatibilizing polymer, typically a block or graft copolymer. 

Compatibilizer Polymer or copolymer that either added to a polymer blend or generated there during reactive processing modifies its interfacial character and stabilizes the morphology... 

Polymer alloy immiscible but compatibilized polymer blend implies a modified interphase and,... 

Table 5.2 Change of dispersed phase dimensions in compatibilized polymer blends upon annealing (Adapted fiom White and Min 1989)...

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