Compatibilisation Compatibilising effect

Compatibilisers effectively reduce the surface energy per unit area. 

Glarke, J., Glarke, B., Freakley, P K., and Sutherland, I. 2001. Compatibilising effect of carbon black on morphology of NR-NBR blends. Plastics Rubber and Composites 30 39 4. 

Bikiaris, D. N., VassUiou, A., Pavlidou, E., and Karayannidis, G. P. 2005. Compatibilisation effect of PP-g-MA copolymer on i-PP/SiOj nanocomposites prepared by melt mixing. European Polymer Journal 41 1%5-1978. 

Mishra S, Naik JB, Patil YP (2000) The compatibilising effect of maleic anhydride on swelling and mechanical properties of plant-fiber-reinforced novolac composites. Compos Sci Technol 60(9) 1729-1735... 

The mechanical compatibilisation of polymer blends is conceptually an attractive route, leading to unique property combinations and the recycling of mixed polymer scrap. There is considerable impetus behind discovering polymers that exhibit such compatibilising effects and to understand the mechanisms by which they function. Blends would result if certain types of plastic soft-drink bottles were granulated and processed. A bottle type of interest consists of a PET container with an HOPE pedestal, which is needed because the blown bottle has a rounded bottom. It is quite obvious that PET and any PO would be grossly incompatible and that a very effective compatibiliser would be needed to give the blend adequate mechanical properties for any subsequent application [76]. 

Blends used to create MFCs can be separated into two broad categories those containing two condensation polymers that will cause a self-compatibilisation effect in the composite, and those requiring the addition of a compatibilizer if a chemical reaction between the constituent polymers is desired. For example, blends combining polyesters with polyamides fall into the former category while blends containing a polyolefin component belong to the latter. 

Pillai and co-workers demonstrated an effective way of using a compatibiliser to improve the PMMA and styrene-butadiene rubber (SBR) system. They created thin films of polymers of poor solubility using silane compatibiliser additives [40] in that work organosilanes containing Cg, Cio, Q2 and Cig aliphatic chains were used in the PMMA/SBR blends. It was found that the compatibiliser effect of organosilane was largely dependent upon the number of carbon atoms in the aliphatic chain. The reasons for that phenomenon was primarily due to the steric effect, as silane-type compounds with different aliphatic chain lengths develop interfacial layers of different thicknesses [40]. 

Maleic anhydride (MA)-, bismaleimide (BMI)-, and acrylic acid (AA)-functionalised iPP were shown to act as compatibilising agents for ternary iPP/PA6/EPDM blends. The compatibilising effect follows the order iPP-MA iPP-BMI>iPP-AA for an optimum amount of 3 wt%. 

Papke N. and Kargar-Kocsis J., Thermoplastic elastomer based on compatibilised poly(ethyleneterphtha-late) blend Effect of rubber type and dynamic curing. Polymer, 42, 1109, 2001. 

Blends of poly (ethylene terephthalate) (PETP) and polypropylene (PP) with different rheological properties were dry blended or compounded, and extrusion foamed using both physical blowing and chemical agents, and the foam properties compared with those of foam produced from the individual components in the absence of compatibilisers and rheology modifiers. The foams were characterised by measurement of density, cell size and thermal properties. Low density foam with a fine cell size was obtained by addition of a compatibiliser and a co-agent, and foamed using carbon dioxide. The presence of PP or a polyolefin-based compatibiliser did not effect... 

A stndy was made of the effects of foam formulation and process conditions and liner composition on the adhesion of HCFC-141b blown rigid PU foam thermal insulation to refrigerator liner protective layers made of ABS, high-impact PS (HIPS), PE and blends of HIPS and PE containing a compatibiliser and adhesion promoter. A tensile test was used to quantify the level of adhesion before and after thermal cycling, and the Brett mould was used for laboratory simulations of foam adhesion within... 

Diblock copolymers, especially those containing a block chemically identical to one of the blend components, are more effective than triblocks or graft copolymers. Thermodynamic calculations indicate that efficient compat-ibilisation can be achieved with multiblock copolymers [47], potentially for heterogeneous mixed blends. Miscibility of particular segments of the copolymer in one of the phases of the bend is required. Compatibilisers for blends consisting of mixtures of polyolefins are of major interest for recyclates. Random poly(ethylene-co-propylene) is an effective compatibiliser for LDPE-PP, HDPE-PP or LLDPE-PP blends. The impact performance of PE-PP was improved by the addition of very low density PE or elastomeric poly(styrene-block-(ethylene-co-butylene-l)-block styrene) triblock copolymers (SEBS) [52]. 

Compatibility of PE with PVC is improved by poly(ethylene-graft-vinyl chloride) or partial chlorinated PE. To compatibilise blends of PE with PET, common for the scrap of beverage bottles, EPDM or SEBS are effective additives [56]. 

Kandola, B. K., Smart, G., Horrocks, A. R., Joseph, P., Zhang, S., Hull, T. R., Ebdon, J., Hunt, B., and Cook, A., Effect of different compatibilisers on nanoclay dispersion, thermal stability, and burning behavior of polypropylene-nanoclay blends, J. Appl. Polym. Sci., 2008, 108, 816-824. 

Polyvinyl chloride/montmorillonite nanocomposites were prepared using an epoxy resin, as compatibiliser, and the effect of this compatibiliser on the optical properties of the nanocomposites investigated. It was found that the transparency of the nanocomposites improved with increasing content of montmorillonite, which was pretreated with the epoxy resin. The good transparency of the nanocomposites also indicated that the epoxy resin improved the processing stability of the nanocomposites. 3 refs. 

Thus, termination of oxazoline polymerization with potassium hydroxide gave hydroxy-terminated polymers, which in the presence of tin octoate were capable of initiating the anionic polymerization of -caprolac-tone [287] giving the corresponding block copolymer, acting as effective compatibiliser. 

The problem of physical blends is not only the formation of a stable morphology. A more important problem for the users of such materials is the changing and most often the lowering of material properties. Table 9 [13] lists the effect of the reactive compatibilisation of polypropylene PA-6 blends of different compositions ... 

The effects of minor proportions of PVC and PS in the polyolefins are quite dramatic. As little as 5% of PVC or PS in LDPE reduces the impact strength (toughness) of the latter by about 65%. This results from their presence as separate phases in the polyolefin matrix which leads to rapid crack propagation on impact. The effect of PP is very much less 10% of PP in LDPE reduced the energy absorbing capacity (toughness) of the matrix by only 1 % and 20% of PP reduced it by only 5%. The addition of block copolymers which act as compatibilisers or more correctly solid-phase dispersants (SPDs) for a second incompatible phase reduces the size of the heterogeneous domains and improves impact resistance. However, a considerable concentration ( 20%) of SPD is required, which unacceptably increases the cost in most cases. 

In order to obtain a cost-effective biodegradable plastic, the blends of polyolefin with starch are stiU one of the best alternatives due to their low price, better properties, broad suppliers, and mature processing facilities and techniques etc. However, starch and polyolefin blends are incompatible at the molecular level, which often leads to poor performance. In order to overcome this drawback, either polyolefins or starch can be modified by introducing a compatibilising agent into the blend. 

The optimal percentage of PP-MAH resulting in dramatically improved ductility was found to be 10 wt% [42]. The general effects of a compatibiliser are the following [43, 44] ... 

Polypropylene/calcium carbonate nanocompwsites - effects of processing techniques and maleated polypropylene compatibiliser. eXPRESS Polymer Letters, Vol. 4, p>p. (611-620)... 

This weakness of the interfaces between most immiscible polymers explains why the mechanical properties of two-phase polymer mixtures are generally so poor. However, as we saw in chapter 6, we can modify the interfaces between immiscible polymers using block copolymers. In section 6 we concentrated on the role of such so-called compatibilisers in lowering the energy of the interface between the immiscible phases. However, in addition to this effect... 

Othman, N., Ismail, FI., and Mariatti, M. 2006. Effect of compatibilisers on mechanical and thermal properties of bentonite filled polypropylene composites. Polymer Degradation and Stability... 

Siregar JP, Sapuan SM, Rahman MZA, Zaman HMDK (2009) The effect of compatibilising agent and surface modification on the physical properties of short pineapple leaf fibre (PALF) reinforced high impact polystyrene (HIPS) composites. Polym Polym Compos 17 379-384... 

Rana AK, Mandal A, Bandyopadhyay S (2003) Short jute fiber reinforced polypropylene composites effect of compatibiliser, impact modifier and fiber loading. Compos Sci Technol 63 801-806... 

Triblock polymers such as PPPPPP-QQQQQ-TT RRRRRR are sometimes used too, but they are not necessarily more effective than diblock types. Core-shell copolymers such as glycidyl methacrylate-ethylene-vinyl acetate, containing both polar and nonpolar units, have been used to compatibilise and toughen blends of two brittle polymers. 

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