Compatibilizing additives

Reactive compatibilization of engineering thermoplastic PET with PP through functionalization has been reported by Xanthos et al. [57]. Acrylic acid modified PP was used for compatibilization. Additives such as magnesium acetate and p-toluene sulfonic acid were evaluated as the catalyst for the potential interchange or esterification reaction that could occur in the melt. The blend characterization through scanning electron microscopy, IR spectroscopy, differential scanning calorimetry, and... 

Effective compatibilization of binary polymer blends by addition of a copolymer reduces the dispersed particles size and Vj [Anastasiadis et al, 1987 Wu, 1987 Patterson et ai, 1971]. An illustration is shown on Figure 4.15. The effect of compatibilizer addition is similar to the emulsification of the classical emulsions. In the former systems, the compatibilizer effect on the drop size and Vj follows the same behavior as the emulsion drop size reduction upon addition of a surfactant. The latter behavior is usually described as the titration curve that characterizes the surfactant efficiency. The shape of the titration curve depends on the type of emulsifier and the emulsification process, e.g., mixing time and equipment. However, the amount of emulsifier to saturate the interface also depends on the affinity of emulsifier to the dispersed phase, the size of the dispersion, the orientation of the emulsifier at the interface and its ability to prevent flocculation and coalescence [Djakovic et al., 1987]. A similar behavior is to be expected for polymer blends upon addition of a compatibilizer. 

PA/PC Dexter Plasties Dexcarb 500 Compatibilizing additive Crystalline/ Amorphous ... 

How can compatibilizing additives allow the more efficient use of regrind and recycled PO content ... 

SAXS has been mainly used to study morphology of the semicrystalline blends, cf. how it is affected by composition, crystallization rate, compatibilization, additives, etc. However, it can also be used to study local structures in molten polymer blends, for example, within the interphasial region. The method has been used for liquid, glassy, and ciystaUine systems to determine the spinodal and binodal temperatures as well as to measure Xi2- A reasonable agreement between the values measured by different methods was obtained (Harris et al. 1983 RiedI and Prud homme 1984 Barlow and Paul 1987). 

During these reactions, the copolymers are produced at the interface. The method is superior to that of compatibilizer addition. Since TSEs are operated with short residence time, to complete the reactive compatibilization, one must use either high concentration of reactive groups, highly reactive functional groups, or efficient catalyst hence, it is required that ... 

Research efforts have been focused largely on the methods of improving the compatibility between PPE and polyamides. Several compatibilizer additives were... 

This can allow for higher end use of a plastic mixture than without a compatibilizer additive. Compatibilizers exist for polyethylene (PE)/PVC blends, PE/PS blends, PVC/PS blends and other more specialized plastics. 

Samal et al. [35] described the properties of PP/banana-glass fiber composites and concluded that glass fiber addition led to improved mechanical performance of the composite and decreased water uptake. They also reported better interfacial adhesion and thermal properties with compatibilizer addition and hybridization. 

Because recycled plastics have had a first use and have been environmentally exposed, required conversion processes are often more stringent. For example, compounding may have to be done on a twin rather than a single-screw extruder for dispersive mixing. In addition, compounding purification steps such as devolatilization and melt filtration may be required for some recycled feedstock. Consequently, the compounding process can have a significant impact on the overall conversion cost. Another contributor to conversion cost is the compatibilizer additive. The most effective of these additives cost about 2.00 per pound. This adds 10 cents per pound of product at a 5% level of compatibilizer additive. 

Bettini SHP, Bonse BC, Melo EA, Munoz PAR (2010) Effect of sawdust surface treatment and compatibilizer addition on mechanical behavior, morphology, and moisture uptake of polypropylene/sawdust eomposites. Polym Eng Sd 50 978-985... 

Recycled materials of many types are coming onto the market. Some companies may even choose to make polymers specifically as compatibilizing additives for selected types of recycled materials. The construction, pipe, and transportation industries are candidates for many of these applications. Ground thermosets with high filler loadings will be an important source of new fillers and manufacturers may be required to use these products in some applications. Recycled textile fibers can serve as reinforcements, which add value to composites if they can be collected in usable forms. 

Table 3.1 Ternary (Nonreactive) Compatibilizer Additives for Poiymer Biends ...

PVC HOPE Chlorinated PE block and random chlorination Improved dispersion and increased elastic recovery observed with compatibilizer addition no difference between block and random chlorination 54... 

Mindel S, noted to be a PSF/PC blend [70], does not require compatibilization additives, as PSF and PC are mechanically compatible. This blend is phase separated but exhibits good mechanical compatibihty and improved hydrolytic stability over PC. Radel R blends under the tradename Acudel (composition not disclosed) have been positioned between PSF and Radel R in performance attributes, and indeed, the property profile is that expected of a blend of Radel R and PSF [71]. 

In summary, addition of small amount of LCP can enhances the crystallinity of thermoplastics, this shows nucleating capability of LCP for thermoplastics. Most conunercial LCPs are incompatible with thermoplastics leading to the properties of LCP/thermoplastic blends to fall short of expectations. Poor interfacial adhesion remains a major obstacle in achieving high performance in situ composites. Thus, suitable compatibilizers additions needed to improve the interfacial adhesion of blend components. 

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