Poly compatibilization using

Figure 4.13 Compatibilization of poly(ether ketone) with poly(isobutylene) using Janus wedge hydrogen bonding (Binder et al. 2005).

In order to obtain materials stable with good properties, the blends have to be compatibilized. In this work, we have investigated the effects of the compatibilization on the structure, rheological, and mechanical properties of blends of PET and PP. The compatibilizer used in this study is a triblock copolymer consisting of polystyrene end-blocks and poly(ethylene-butylene) mid-blocks grafted with maleic anhydride, MA-g-SEBS. This copolymer was already used to compatibilize other blends of polar and apolar polymers with satisfactory results. 

Mixing of polymers is an important process in the polymer industry by combining the strength of different polymers through blending, new products with desirable physical properties can be produced [2]. FT-IR imaging with a micro-ATR objective has been used to study the effect of a compatibilizer on the mixing of two immiscible polymers, namely polystyrene (PS) and low-density polyethylene (LDPE). The compatibilizer used in this study is a triblock copolymer of polystyrene-f -poly(ethylene-butylene)-f)-polystyrene (SEES). The blends are prepared with a micro-extruder, which allows small amounts of the materials to be blended [2]. The two polymers are easily characterized by their specific absorption bands at 1492 and 1450 cm for PS and the band at 1466 cm for LDPE. 

Blends with good mechanical properties can be made from DMPPO and polymers with which DMPPO is incompatible if an appropriate additive, compatibilizing agent, or treatment is used to increase the dispersion of the two phases. Such blends include mixtures of DMPPO with nylon, polycarbonate, polyester, ABS, and poly(phenylene sulfide). 

Compatibilization along with dynamic vulcanization techniques have been used in thermoplastic elastomer blends of poly(butylene terephthalate) and ethylene propylene diene rubber by Moffett and Dekkers [28]. In situ formation of graft copolymer can be obtained by the use of suitably functionalized rubbers. By the usage of conventional vulcanizing agents for EPDM, the dynamic vulcanization of the blend can be achieved. The optimum effect of compatibilization along with dynamic vulcanization can be obtained only when the compatibilization is done before the rubber phase is dispersed. 

Second, in the case of polyoxazoline hybrid, the characteristic property of high compatibility of organic polymer with polar organic commodity polymers such as poly(vinyl chloride) or polyamide can be used as a type of compatibilizer. That is, it makes possible to incorporate the third organic polymer in the polyoxazoline-silica gel hybrid. 

These polymers show lower water uptake than the analogous sulfonated poly(arylene ether sulfone) materials, possibly suggesting some interaction between the aromatic nitrile and sulfonic acid. The phosphine oxide functional moiety could also be used as a compatibilizer with other materials. Sulfonated poly(arylene ether phosphine oxide sulfone) terpoly-mers have been prepared both with sulfonated triphenyl phosphine oxide and with triphenyl phosphine oxide with 3,3 -disulfonate-4,4 —dichlorodiphenyl sulfone as the sulfonic acid bearing monomer. Block copolymers containing phosphine oxide appear to avoid the ether—ether interchange that results when non—phosphine oxide blocks are utilized, and this is being further pursued. ... 

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. 

It has been found by Baird and others [74-77] that the presence of LCP may accelerate and presumably direct the crystallization of conventional polymers (PET, etc.). Porter [76] has shown that, by blending biphasic polymers such as the PET-poly HBA copolymers, miscibility may be achieved between the conventional phase of the biphasic polymer with another conventional polymer that component is miscible with, i.e., X7-G/PBT. The latter phenomena may offer direction in the search for useful compatibilizing agents for LCP/conven-tional polymer systems. 

In order to overcome the build-up of these stresses, the addition of triblock terpolymers as compatibilizing agents with an elastomeric middle block and end blocks of PS and PMMA, respectively, appears advantageous. One example is the use of polystyrene-Wocfc-poly(l,4-butadiene)-W0cfc-poly(methyl methacrylate)... 

SBM) as a compatibilizer. As a result of the particular thermodynamic interaction between the relevant blocks and the blend components, a discontinuous and nanoscale distribution of the elastomer at the interface, the so-called raspberry morphology, is observed (Fig. 15). Similar morphologies have also been observed when using triblock terpolymers with hydrogenated middle blocks (polystyrene-W<9ck-poly(ethylene-C0-butylene)-Wock-poly(methyl methacrylate), SEBM). It is this discontinuous interfacial coverage by the elastomer as compared to a continuous layer which allows one to minimize the loss in modulus and to ensure toughening of the PPE/SAN blend [69],... 

Auschra C, Stadler R (1993) Polymer alloys based on poly(2,6-dimethyl-l,4-phenylene ether) and poly(styrene-co-acrylonitrile) using poly(styrene-f>-(ethylene-co-butylene)-b-methyl methacrylate) triblock copolymers as compatibilizers. Macromolecules 26 6364-6377... 

PE graft copolymers were synthesized from PE-OH by Inoue et al. using ATRP techniques, adopting similar techniques as mentioned above [74]. PE-g-PMMA and Polyclhylcnc-gra/f-poly( -bulyl acrylate) (PE-g-PnBA) were prepared through the combination of metallocene-catalyzed ethylene/10-undecen-l-ol copolymerization and conversion of the copolymer into P E-g-Br, as a macroinitiator, for ATRP. Well-defined graft copolymers, PE-g-PMMA and PE-g-PnBA, were confirmed by analyses of the detached side chains. Resulting PE-g-PMMA worked well as a compatibilizer. 

As block copolymers are still rather expensive materials, it may be advantageous to use them as additives to important industrial polymers. In this domain, possibilities are extremely numerous and diverse. They include an improvement of chemical properties such as resistence to degradation agents, or rheological properties such as adhesion of vinylic paints, high impact properties of conventional thermoplastics, or a compatibilization of polyolefins, polystyrene and poly(vinyl chloride) allowing the reuse of polymeric waste products. The above examples illustrate the great intrinsic potential of block copolymers in the quest of new materials with specific properties. 

Thermoset polyurethanes are cross-linked polymers, which are produced by casting or reaction injection molding (RIM). For cast elastomers, TDI in combination with 3,3,-dichloro-4,4,-diphen5lmethanediamine (MOCA) are often used. In the RIM technology, aromatic diamine chain extenders, such as diethyltoluenediamine (DETDA), are used to produce poly(urethane ureas) (47), and replacement of the polyether polyols with amine-terminated polyols produces polyureas (48). The aromatic diamines are soluble in the polyol and provide fast reaction rates. In 1985, internal mold release agents based on zinc stearate compatibilized with primary amines were introduced to the RIM process to minimize mold preparation and scrap from parts tom at demold. Some physical properties of RIM systems are listed in Table 7. 

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... 

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