what is poly propylene?How is it prepared?Say about its propertiese and uses.?

Answer 1

Polypropylene or polypropene (PP) is a thermoplastic polymer, used in a wide variety of applications, including food packaging, textiles, laboratory equipment, loudspeakers, automotive components, and polymer banknotes. An addition polymer made from the monomer propylene, it is unusually resistant to many chemical solvents, bases and acids. Its resin identification code is the number 5 surrounded by a recycling symbol, with the letters "P P" below.
Chemical & physical properties

Most commercial polypropylene has a level of crystallinity intermediate between that of low density polyethylene (LDPE) and high density polyethylene (HDPE); its Young's modulus is also intermediate. Although it is less tough than LDPE, it is much less brittle than HDPE. This allows polypropylene to be used as a replacement for engineering plastics, such as ABS. Polypropylene has very good resistance to fatigue, so that most plastic living hinges, such as those on flip-top bottles, are made from this material. Very thin sheets of polypropylene are used as a dielectric within certain high performance pulse and low loss RF capacitors.

Polypropylene has a melting point of 320 degrees Fahrenheit (160 degrees Celsius). Food containers made from it will not melt in the dishwasher, and do not melt during industrial hot filling processes. For this reason, most plastic tubs for dairy products are polypropylene sealed with aluminium foil (both heat-resistant materials). After the product has cooled, the tub are often given lids of a cheaper (and less heat-resistant) material, such as LDPE or polystyrene. Such containers provide a good hands-on example of the difference in modulus, since the rubbery feeling of LDPE with respect to PP of the same thickness is readily apparent.

A rubbery PP can also be made by a specialized synthesis process, as discussed below. Unlike traditional rubber, it can be melted and recycled, making it a thermoplastic elastomer.

Answer 2

Polypropylene or polypropene (PP) is a thermoplastic polymer, used in a wide variety of applications, including food packaging, textiles, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes. An addition polymer made from the monomer propylene, it is rugged and unusually resistant to many chemical solvents, bases and acids.


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Answer 3

Poly propylene? Never heard of it, I assume it is someone's parrot.

If you mean polypropylene, then it is the polymer formed from the propylene monomer. It's a fairly soft plastic, the front of my notbook is made from polypropylene.

Answer 4

Genral info about Polypropylene:
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Polypropylene powder coatings are chemical modifications of natural polypropylene. In general, thermoplastic powder coatings are difficult to grind into fine particles used to apply thin films, so they are used for functional coatings of greater than 10 mils (0.25 mm) thickness. They are usually applied by the fluidized-bed application technique. Thermosets rarely compete in the same markets as liquid paints.101

Polypropylene powders are applied to conveyor chutes, freezer shelving, chemical processing pipe coating, drum and tank linings, and plating racks.101
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Novel Preparation and Properties of Polypropylene-Vermiculite Nanocomposites:
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A novel approach to the preparation of polymer nanocomposites utilizing a low-molecular-weight reactive modifying reagent has been developed in this study. This is the first report on the fabrication of in situ nanocomposites using maleic anhydride as a reactive reagent that acts both as a modifying additive for the polymeric matrix and as a swelling agent for the silicate. Accordingly, polypropylene-vermiculite nanocomposites with an intercalated or exfoliated structure can be achieved by simple melt mixing of maleic anhydride-modified vermiculite with polypropylene. The nanocomposite structure is evidenced by the absence of vermiculite reflections in the X-ray powder diffraction patterns. Tensile tests show that the tensile modulus and strength of the nanocomposites tend to increase dramatically with vermiculite addition. Such enhancement in mechanical properties results from the formation of intercalated and exfoliated vermiculite reinforcement in the composites. Finally, the thermal properties of the nanocomposites were investigated by means of dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The effects of maleic anhydride addition on the formation of nanometric reinforcement and on the mechanical properties of nanocomposites are discussed.
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Uses of Polypropylene:
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Food Uses Applications


Market Applications:
Cleaners and Detergents
Electronics
Food Uses
Kosher Applications
Personal Care
Rubber and Plastics

Functional Applications:
Chemical Intermediates
Foam Control
Heat Transfer Fluids
Industrial Surfactants


Overview
Certain DOW Polypropylene glycols are suitable for a variety of food additive uses, both direct and indirect. They are typically used in fermentation foam control, and as defoamers in direct, indirect, and secondary food additives. Certain polypropylene glycols and polyglycol copolymers are also available in Kosher grades.

Products
The following products are appropriate for food additives. Although each product has unique properties based on molecular weight and the monomer used, they all share some common properties.

Polypropylene GlycolsPolyglycol Copolymers
P42515-200
P1000TB††112-2
P1200††EP530††
P2000††EP1660

EP1730
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Answer 5

It's uses? Well here in the Army we use it on coats, jackets, and undergarments to keep warm in extremly cold temperatures.

Answer 6

it is a polymer made by repeating a single unit over and over

Answer 7

Polypropylene or polypropene (PP) is a thermoplastic polymer, used in a wide variety of applications, including food packaging, textiles, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes. An addition polymer made from the monomer propylene, it is rugged and unusually resistant to many chemical solvents, bases and acids. Its resin identification code is .

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Chemical & physical properties
Most commercial polypropylene has a level of crystallinity intermediate between that of low density polyethylene (LDPE) and high density polyethylene (HDPE); its Young's modulus is also intermediate. Although it is less tough and flexible than LDPE, it is much less brittle than HDPE. This allows polypropylene to be used as a replacement for engineering plastics, such as ABS. Polypropylene is rugged, often somewhat stiffer than some other plastics, reasonably economical, and can be made translucent when uncolored but not completely transparent as polystyrene or certain other plasics can be made. It can also be made opaque and/or have many kinds of colors. Polypropylene has very good resistance to fatigue, so that most plastic living hinges, such as those on flip-top bottles, are made from this material. Very thin sheets of polypropylene are used as a dielectric within certain high performance pulse and low loss RF capacitors.

Polypropylene has a melting point of 320 degrees Fahrenheit (160 degrees Celsius). Many plastic items for medical or laboratory use can be made from polypropylene which is autoclavable so that it can withstand the heat in an autoclave. Food containers made from it will not melt in the dishwasher, and do not melt during industrial hot filling processes. For this reason, most plastic tubs for dairy products are polypropylene sealed with aluminium foil (both heat-resistant materials). After the product has cooled, the tubs are often given lids of a cheaper (and less heat-resistant) material, such as LDPE or polystyrene. Such containers provide a good hands-on example of the difference in modulus, since the rubbery (softer, more flexible) feeling of LDPE with respect to PP of the same thickness is readily apparent. Rugged, translucent, reusable plastic containers made in a wide variety of shapes and sizes for consumers from various companies such as Rubbermaid and Sterilite are commonly made of polypropylene, although the lids are often made of somewhat more flexible LDPE so they can snap on to the container to close it. When liquid, powdered, or similar consumer products come in disposable plastic bottles which do not need the improved properties of polypropylene, the containers are often made of slightly more economical polyethylene, although transparent plastics such as polyethylene terephthalate are also used for appearance. Plastic pails, wastebaskets, cooler containers, dishes and pitchers are often made of polypropylene or HDPE, both of which commonly have rather similar appearance, feel, and properties at ambient temperature.

A rubbery PP can also be made by a specialized synthesis process, as discussed below. Unlike traditional rubber, it can be melted and recycled, making it a thermoplastic elastomer.

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Synthesis

Short segments of polypropylene, showing examples of isotactic (above) and syndiotactic (below) tacticity.An important concept in understanding the link between the structure of polypropylene and its properties is tacticity. The relative orientation of each methyl group (CH3 in the figure at left) relative to the methyl groups on neighboring monomers has a strong effect on the finished polymer's ability to form crystals, because each methyl group takes up space and constrains backbone bending.

Like most other vinyl polymers, useful polypropylene cannot be made by radical polymerization. The material that results from such a process has methyl groups arranged randomly, and so is called atactic. The lack of long-range order prevents any crystallinity in such a material, giving an amorphous material with very little strength and few redeeming qualities.

A Ziegler-Natta catalyst seems to be able to limit incoming monomers to a specific orientation, only adding them to the polymer chain if they face the right direction. Most commercially available polypropylene is made with titanium chloride catalysts, which produce mostly isotactic polypropylene (the upper chain in the figure above). With the methyl group consistenly on one side, such molecules tend to coil into a helical shape; these helices then line up next to one another to form the crystals that give commercial polypropylene its strength.


A ball-and-stick model of syndiotactic polypropylene.More precisely-engineered Kaminsky catalysts have been made, which offer a much greater level of control. Based on metallocene molecules, these catalysts use organic groups to control the monomers being added, so that a proper choice of catalyst can produce isotactic, syndiotactic, or atactic polypropylene, or even a combination of these. Aside from this qualitative control, they allow better quantitative control, with a much greater ratio of the desired tacticity than provious Ziegler-Natta techniques. They also produce higher molecular weights than traditional catalysts, which can further improve properties.

To produce a rubbery polypropylene, a catalyst can be made which yields isotactic polypropylene, but with the organic groups that influence tacticity held in place by a relatively weak bond. After the catalyst has produced a short length of polymer which is capable of crystallization, light of the proper frequency is used to break this weak bond, and remove the selectivity of the catalyst so that the remaining length of the chain is atactic. The result is a mostly amorphous material with small crystals embedded in it. Since each chain has one end in a crystal but most of its length in the soft, amorphous bulk, the crystalline regions serve the same purpose as vulcanization.

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Answer 8

search in www.wikipedia.com