Commodity plastics polypropylene

The next major commodity plastic worth discussing is polypropylene. Polypropylene is a thermoplastic, crystalline resin. Its production technology is based on Ziegler s discovery in 1953 of metal alkyl-transition metal halide olefin polymerization catalysts. These are heterogeneous coordination systems that produce resin by stereo specific polymerization of propylene. Stereoregular polymers characteristically have monomeric units arranged in orderly periodic steric configuration. 

We can divide commodity plastics into two classes excellent and moderate insulators. Polymers that have negligible polar character, typically those containing only carbon-carbon and carbon-hydrogen bonds, fall into the first class. This group includes polyethylene, polypropylene, and polystyrene. Polymers made from polar monomers are typically modest insulators, due to the interaction of their dipoles with electrical fields. We can further divide moderate insulators into those that have dipoles that involve backbone atoms, such as polyvinyl chloride and polyamides, and those with polar bonds remote from the backbone, such as poly(methyl methacrylate) and poly(vinyl acetate). Dipoles involving backbone atoms are less susceptible to alignment with an electrical field than those remote from the backbone. 

One of the main barriers to the widespread use of biodegradable plastics is their higher production cost compared to petroleum plastics. For example, whereas the cost of most commodity plastics, such as polypropylene, is well below 1 US /kg, the costs of some of the cheapest biodegradable plastics on the... 

PHAs can consist of a diverse set of repeating unit structures and have been studied intensely because the physical properties of these biopolyesters can be similar to petrochemical-derived plastics such as polypropylene (see Table 1). These biologically produced polyesters have already found application as bulk commodity plastics, fishing lines, and for medical use. PHAs have also attracted much attention as biodegradable polymers that can be produced from biorenewable resources. Many excellent reviews on the in vivo or in vitro synthesis of PHAs and their properties and applications exist, underlining the importance of this class of polymers [2, 6, 7, 12, 26-32]. 

Thermoplastic Polymers. Most thermoplastic polymers are used in high-volume, widely recognized applications, so they are often referred to as commodity plastics. (We will elaborate upon the distinction between a polymer and a plastic in Chapter 7, but for now we simply note that a plastic is a polymer that contains other additives and is usually identified by a variety of commercial trade names. There are numerous databases, both in books [1] and on the Internet [2], that can be used to identify the primary polymer components of most plastics. With a few notable exceptions, we will refer to most polymers by their generic chemical name.) The most common commodity thermoplastics are polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC) and polystyrene (PS). These thermoplastics all have in common the general repeat unit -(CHX-CH2)-, where -X is -H for PE, -CH3 for PP, -Cl for PVC, and a benzene ring for PS. When we discuss polymerization reactions in Chapter 3, we will see that all of these thermoplastics can be produced by the same type of reaction. 

Commodity and engineering polymers. On the basis of end use and economic considerations, polymers can be divided into two major classes commodity plastics and engineering polymers. Commodity plastics are characterized by high volume and low cost. They are used frequently in the form of disposable items such as packaging film, but also find application in durable goods. Commodity plastics comprise principally of four major thermoplastic polymers polystyrene, polyethylene, polypropylene, and poly(vinyl chloride). 

Thermoplastics may be further subdivided into two broad categories on the basis of their cost and suitable end uses. Commodity plastics are typified by high volume production, good properties, and low resin cost. The four major commodity plastics are polyethylene, polypropylene, poly(vinyl chloride), and polystyrene. Their adequate properties and low cost have led to the extensive use of these plastics in packaging applications where they are very competitive with paper, steel, and glass. They are also used for some less demanding applications as components of durable goods (Table 22.1). 

Many polymers are now manufactured on a, commercial scale using Ziegler-Natta catalysts. Indeed, stereoregular (isotactic) polypropylene of high molecular weight, which cannot be made by free-radical or ionic polymerization, has already achieved the status of a commodity plastic. The scientific and practical significance of Ziegler and Natta s work earned them the joint award of the Nobel Prize in Chemistry in 1963. 

Plastics are not, as many people believe, new materials. Their origin can be traced to 1847 when Shonbein produced the first thermoplastic resin, celluloid, by reaction of cellulose with nitric acid. However, the general acceptance and commercialization of plastics began during the Second World War when natural polymers, such as natural rubber, were in short supply. Thus, polystyrene was developed in 1937, low density polyethylene in 1941, whereas other commodity plastics such as high density polyethylene and polypropylene were introduced in 1957. 

Thermoplastics, in particular the commodity plastics, polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC) and polystyrene (PS), are the most commonly used in packaging (over 90% of packaging is thermoplastics, followed by a small amount of thermosets, composites, rubber and thermoplastic elastomers (TPE). 

Abstract Polyhydroxyalkanoate (PHA) is a plastic-like material synthesized by many bacteria. PHA serves as an energy and carbon storage componnd for the bacteria. PHA can be extracted and purified from the bacterial cells and the resulting product resembles some commodity plastics such as polypropylene. Because PHA is a microbial product, there are natural enzymes that can degrade and decompose PHA. Therefore, PHA is an attractive material that can be developed as a bio-based and biodegradable plastic. In addition, PHA is also known to be biocompatible and can be used in medical devices and also as bioresorbable tissue engineering scaffolds. In this chapter, a brief introduction about PHA and the fermentation feedstock for its production are given. 

Despite its origin form the nature, PLA s good stiffness and strength has enabled it to compete with other existing chemically based commodity plastics. Previous study on the mechanical properties of neat PLA by Jacobsen et al. [1] showed that PLA has great potential to be a substitute polymer for petroleum based plastics. The respective values of mechanical properties of PLA [2] with comparison of other petroleum based plastics e.g. polypropylene (PP) [3], polystyrene (PS) [4], high density polyethylene (HOPE) [5], polyamide (PA6) [6] shown in Fig. 11.2. 

Polyethylenes and polypropylene are bulk commodity plastics but a precondition of numerous industrial and consumers applications is a considerable improvement in their flammability characteristics. ... 

Polyethylene and polypropylene are ubiquitous commodity plastics found in applications varying from household items such as grocery bags, containers, toys and appliance housings, to high-tech products such as engineering plastics, automotive parts, medical appliances and even prosthetic implants. They can be either amorphous or highly crystalline, and behave as thermoplastics, thermoplastic elastomers or thermosets. 

In summary, the apparent simphdty of your everyday polyethylene and polypropylene consumer goods is deceptive. Few industrial polymers can claim such richness in catalyst types, reactor configurations and microstructural complexity. In this chapter, we will explain how, from such simple monomers, polyolefins have become the dominant commodity plastic in the 21st century. 

With ever-increasing oil prices, recycled plastics are becoming an economical alternative for the production of a wide range of commodity plastic parts. Polyolefinic polymers, such as polyethylene (PE) and polypropylene (PP), contain approximately 14% hydrogen these materials could provide the hydrogen required for thermal coprocessing with biomass, which could lead to an increase of the liquid production of oligomers or short chain polymeric materials. 

Economical manufacturing methods of mass production and improvements to the properties of finished products have in many applications greatly helped to replace traditional materials, such as metals or wood, with plastics and rubbers. In particular, polypropylene (PP) is the fastest growing commodity plastic world-wide. It has found its place in many sectors such as building, transportation (automotive, railways, etc.), electrical engineering (electrical/household appliances, housings, etc.) or paper industry. 

Omitting the construction and demolition debris from the calculations, the composition (by volume this time) is as follows paper and paperboard 50%, plastics 14%, metals 12%, glass 4%, organics 6%, and miscellaneous 14%. All plastic packaging (post-consumer, industrial, commercial, and institutional) represented about 8% of the overall refuse. It is a reasonable assumption that the composition of plastics discarded in landfills is a reflection of the quantities produced for packaging applications the commodity plastics polyethylene, polypropylene, polystyrene, and poly(vinyl chloride) should be well represented (see Ethylene POLYMERS PROPYLENE Polymers (PP) Styrene Polymers Vinyl Chloride Polymers). 

Apart from its biodegradability, the most attractive feature of PLA is its similar properties to commodity plastics such as polypropylene. Main disadvantages of PLA are its brittleness, low thermal stability, relatively poor barrier properties, and high price. Blending and copolymerization with other polymer are used to overcome these issues. 

Semicrystalline polymers constitute an important group of polymers with a very broad range of applications, in particular, the family of polyolefins, including poly-ethylenes and polypropylenes, is one of the most prominent commodity plastics that make up a great part of the world s plastic market. The rapid development of new catalysts has allowed for the tailored design of macromolecules with defined semicrystalline morphologies and thus defined properties. Besides these commodity plastics, there are a number of technical and functional polymers that have a typical semicrystalline structure (e.g., PEEK, PVDE, PTFE). 

Plastic materials have become basic and indispensable in our life. To protect against contamination and conserve them, food products are distributed in different plastic packages bags, bottles, boxes, etc. that contain all kinds of edible products liquid (water, milk, cold beverages) or solid (fruit, meat, fish, frozen foods, etc.). The group of commercial plastics, also termed commodity plastics, consists of the most used polymers in terms of volume and number of applications. They are mainly polystyrene (PS), polypropylene (PP), high-and low-density polyethylene (HDPE, LDPE), polyethylene terephthalate (PET) and, in lower proportion, polycarbonate (PC) [71. 

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