Compatibilisation Compatibilising process

A novel approach is used to compatibilise a blend without addition of premade copolymers or functionalisation of polymers lacking functional groups. Solid-state shear pulverisation (S3P) processes polymers at temperatures below the melt transition (for semicrystalline polymers) or the glass transition (for amorphous polymers). The polymer, introduced as pellets or flakes into the pulveriser. 

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... 

The company claims easy processing results from the high compatibility of the blend components. The formulation consists of more than 10% PLA (purchased from NatureWorks LLC) plus a biodegradable co-polyester and special additives. FKuR says a special combination of compatibilisers permits coupling between the PLA and the co-polyester. The compound is homogeneous, which allows the film to be drawn down to 8 microns. Film up to 110 microns thick is 90% degraded after twelve weeks in composting conditions. 

Chlorinated polyethylene was evaluated as a compatibiliser forpoly(vinyl chloride) composites containing 25% or 40% wood flour. The compositions also contained lubricants, a stabiliser and a processing aid. Following blending, the composites were characterised by rheology studies and measurements of melt strength. The addition of chlorinated polyethylene significantly enhanced the processability of... 

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, it appears that chemical reactivity or ionic-cross interactions could lead to in situ compatibilising or miscibility enhancement during melt-mixing. However, several questions remain. How does the reactivity modify the thermodynamic balance, the reciprocal miscibility or the rheological behaviour of the melt Or, how the covalent or ionic bonding influence the interfacial adhesion processability and final mechanical properties of the immiscible blends ... 

To improve the miscibility of polymer systems, a well-known method is to add compatibilisers or to form compatibilising compounds during processing. These substances are located in the interface layer and improve the blend morphology and the material properties. 

The chemical structure of polyamides and polyester involves only few chances for a reactive compatibilisation during melt processing with short residence times... 

A highlight of the reactive compatibilisation of extremely incompatible polymers is the chemical bonding between the anti-adhesive PTFE and the polar polyamides. It had been assumed for a long time that a chemical bonding between PTFE and polyamide is impossible because there was no appropriate reaction mechanism. PTFE is a highly crystalline polymer which could only be processed by using special equipment. The utilisation in tribological systems is a well-known... 

The aim of this chapter is to evaluate the influence of compatibiliser and processing conditions on the dispersion behavior of nanoclays as filler in a fiber-formed PP matrix as well as the tensile strength of PP nanocomposites. 

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. 

Polypropylene (PP500P, SABIC) has melt flow rate of 3.1 (2.16 kg at 230 °C) and density of 905 kg/m3 was used as matrix resin. Nano-sized synthetic ultrafine surface treated precipitated calcium carbonate (Socal 312, Solvay, France) with mean particle diameter of 70 nm used as filler phase. PP-g-MAH compatibiliser (Priex 20097, Solvay, France) with a maleic anhydride content of 0.05 wt % and MFI of 15 (2.16 kg at 230 °C) was employed to promote the interfacial interaction between nano-CaC03 and PP, and to extend the dispersion of nanoparticles in polymer matrix. Compounds used as processing materials are listed in the table 1. 

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

While processing, phase morphology depends on the process parameters, intrinsic properties, and interfacial properties of the component polymers. The blend can be further modified by a third component, widely known as a compatibiliser which stabilises the phase morphology and improves the interfacial adhesion. 

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]. 

Traugott and co-workers [41] place the emphasis on aspects of PP, acrylonitrile-butadiene-styrene (ABS) and polycarbonate (PC) blends with ABS or impaa modifiers. Material development benefits from a host of recent technical advancements such as catalysis, reaction engineering, impact modification and compatibilisation. Some examples of these are fourth generation Ziegler-Natta and metallocene polyolefin catalysts, highly efficient solution processes (PP and ABS) and copolymer modifiers. 

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