Polymer blends with polypropylene

Kraton polymers blended with polypropylene can provide films with elasticity and strength, puncture resistance, low permanent set to prevent finger marks and indentation due to handling, high oxygen permeability, moisture-barrier properties, and clingJ ]... 

Film Applications Kraton polymers blended with polypropylene and coextruded with ethylene vinyl acetate to form multilayer structures are suitable for food-wrap applications and can offer an excellent... 

Polypropylene as Dispersed Phase Typical polymer blends with isotactic polypropylene, PP, are the PP/PE blends, in which PP is the first crystallizing component. 

Morphology of three polypropylene (PP)/polyethylene (PE) blends with different viscosity ratios. The viscosity ratio is 3.9 for PP/PE-1 (a), 1 for PP/PE-2 (b), and 0.5 for PP/PE-3 (c). The surface of the blend was etched with xylene to improve morphology observation. (Reproduced from Hong, J. S., K. H. Ahn, and S. J. Lee. 2005a. Strain hardening behavior of polymer blends with fibril morphology. Rheologica Acta 45 202-208, with permission.)... 

Austin, J. R. and Kontopoulou, M. 2006. Effect of organoclay content on the rheology, morphology, and physical properties of polyolefin elastomers and their blends with polypropylene. Polymer Engineering and Science 46 1491-1501. 

Tchoudakov, R., Breuer, O., Narkis, M., and Siegmann, A. (1996) Conductive polymer blends with low carbon black loading polypropylene/polyamide. Polym. Eng. Sci., 36, 1336. 

Rubber blending of PP is used to improve its impact properties. Miscibility, however, is exception rather than rule in polymer systems and consequently processing of polymer blends is quite complicated with respect to control of morphology. An induced morphology may be preserved using radiation techniques to crosslink the dispersed phase in polymer blends isotactic-polypropylene/ethylene- propylene (diene... 

The polyolefin block copolymers are lower in cost. Their suggested applications (74) include wire and cable insulation, replacements for PVC and styrenic block copolymers, and blends with polypropylene, either to improve impact resistance or as the soft phase in a hard polymer/elastomer combination. Processing conditions are similar to those for polyethylene, and thermal stability is excellent. 

Polymer alloys are commercial polymer blends with improvanent in property balance with the use of compatibilizers. Texas A M University [1] has patented a com-patibilizer that can result in a product with high impact resistance as well as scratch resistance. The blend is composed of HIPS or polypropylene (PP) and a compati-bilizer made of a triblock copolymer of styrene-ethylene-propylene. Udipi [2] discovered that polymer blends composed of PC, a copolyester of PETG, and nitrile rubber exhibit a superior balance of properties. Reactive compatibilization of PC/ SAN blends at various AN compositions were conducted by Wildes et al. [3] using a SAN-amine compatibilizer. PC and SAN were found to be miscible over a range of AN composition by Mendelson [5]. Nylon/ABS blends can be compatibilized by use of SAN-maleic acid (Lavengood et al. [6]). Styrene-GMA copolymers can be used as compatibilizers for PS/PA, PS/PBT, PS/PET, and PPO/PBT blends. 

Santrach [1] observed that HDT values were dependent on the amount and types of film former and lubricant. Fiber glass that has been sized for polyamide gives HDT values of about 240-252°C for nylon 6,6 levels above 50% in the polymer phase of compatibilized blends with polypropylene. However, in polypropylene type fiber glass, the HDT is only about 150-155°C. These observations are consistent with Santrach s comments about the addition of glass fibers to crystalline resins giving... 

R. Tchoudakov, O. Breuer, M. Narkis, and A. Siegmann, Conductive Polymer Blends with Low Carbon Black Loading Polypropylene/Polyamide, Polym. Eng. ScL 36, 1336-1346 (1996). 

In the early history of polypropylene technology, blends with ethylene propylene copolymer were introduced for toughening polypropylene. Subsequently block copolymers of polypropylene with random ethylene propylene copolymer rubber were produced in the polymerization reaction. Dynamic vulcanization of ethylene propylene terpolymer in blends with polypropylene together with hydrocarbon oils was a third technology. The first TPO was elastomer (ethylene)-modified propylene (EP polymer) marketed to overcome polypropylene s weakness that cold temperature negatively impacts resistance. 

The aim of the present woik was preparation of microfibrillar-phase morphology in the PP/PE blends with polypropylene as a minority component. For these purposes an extrasion line based on conventional singlescrew extrader and semihyperbolic-converging die was employed. It was proved that the formation of fibrillar structure in one processing step can be achieved using blends with various content of polypropylene (the blends with 20, 30 and 40 wt.% of PP were studied) and both compounded and hand-mixed materials (twin-screw extruder compounded and non-compounded materials were processed). Since the structure and properties of polymer parts are mutually interconnected, the extruded tapes with microfibrillar morphology were examined by several methods of structure analysis and measurements of properties. The results can be summarized as follows ... 

Polymer Blends. Commercial blends of nylon with other polymers have also been produced in order to obtain a balance of the properties of the two materials or to reduce moisture uptake. Blends of nylon-6,6 with poly(phenylene oxide) have been most successflil, but blends of nylon-6,6 and nylon-6 with polypropylene have also been introduced. 

Polymer Blends. The miscibility of poly(ethylene oxide) with a number of other polymers has been studied, eg, with poly (methyl methacrylate) (18—23), poly(vinyl acetate) (24—27), polyvinylpyrroHdinone (28), nylon (29), poly(vinyl alcohol) (30), phenoxy resins (31), cellulose (32), cellulose ethers (33), poly(vinyl chloride) (34), poly(lactic acid) (35), poly(hydroxybutyrate) (36), poly(acryhc acid) (37), polypropylene (38), and polyethylene (39). 

Other thermoplastic elastomer combiaations, ia which the elastomer phase may or may not be cross-linked, include blends of polypropylene with nitrile (30,31), butyl (33), and natural (34) mbbers, blends of PVC with nitrile mbber (35,36), and blends of halogenated polyolefins with ethylene interpolymers (29). Collectively, thermoplastic elastomers of this type ate referred to herein as hard polymer/elastomer combinations. Some of the more important examples of the various types are shown in Table 3. 

---