Thermosets, world production

The primary UPR end markets are construction, automotive, and marine industries widi applications such as house paneling, tub and shower applications, chemical-resistant storage tanks, pultruded profiles, and fiberglass composite boat hulls. The UPR industry is mature, with a world production close to 1.7 million tons (Table 2.2), but must face two important issues increasingly strict regulations for styrene emissions and poor recycling potential for polyester thermosets.48 49... 

Figure 33-2. Annual change in world production., Pr (tons/annum) for thermoplastics and thermosets (PL), natural fibers (NF), chemical fibers (CF), synthetic rubbers (SR), and natural rubber (NR) since the year 1940. (After H.-G. Elias.)...

The world production of plastics in 1900 was about 30,000 t - in the year 2010 it had reached 265 Mt, with thermoplastics contributing about 90 % of this amount, while the rest was thermosets. For the last 20 years, plastic production has increased at the rate of about 5 % per year, with no saturation in sight. In 2010, China accounted for 23.5 % of plastic production, whereas Europe and the North American (NAFTA) region contributed 21.5 % and 20.5 %, respectively (Plastics-the facts 2011, PlasticsEurope, 20th ed). According to a report by Global Industry Analysts Inc., global plastic cmisumption is set to reach 297.5 Mt by 2015. 

Table 1-2 provides estimates of the major types of plastics consumed yearly worldwide that now total 339,990 million lb (154 million tons). About 90% are thermoplastics (TPs) and 10% thermoset (TS) plastics. USA and Europe consumption s are each about one-third of the world total. There are well over 35,000 different type plastic materials worldwide. However, most of them are not used in large quantities they have specific performance and/or cost capabilities generally for specific products by specific processes that principally include many thousands of products (Chapters 6 7). 

Worldwide the term preferred is plastics. The fact is that (1) this industry identifies itself as a plastics industry, (2) practically all people worldwide use the term plastics, (3) practically all materials, products, exhibition shows, technical meetings, advertising, etc. use the term plastics, and (4) as it is repeatedly said, this is a World of Plastics. As shown in this book there are terms that overlap and also interfere with each other. A major example is stating that thermoplastics (TPs) are cured during processing cure occurs only with thermoset plas-... 

To the synthetic thermoplastics and thermosets of Figure 3, the synthetic rubbers and elastomers may be added. In 1972 they amounted to more than 15 billion pounds worldwide. SBR has been the workhorse of the rubber industry since World War II. Being used in tires, it amounts to over half of all rubber production. G. M. Burnett and G. G. Cameron have investigated the way its crosslinking during polymerization affects its properties and processability. For years it... 

Research on the pyrolysis of thermoset plastics is less common than thermoplastic pyrolysis research. Thermosets are most often used in composite materials which contain many different components, mainly fibre reinforcement, fillers and the thermoset or polymer, which is the matrix or continuous phase. There has been interest in the application of the technology of pyrolysis to recycle composite plastics [25, 26]. Product yields of gas, oil/wax and char are complicated and misleading because of the wide variety of formulations used in the production of the composite. For example, a high amount of filler and fibre reinforcement results in a high solid residue and inevitably a reduced gas and oiFwax yield. Similarly, in many cases, the polymeric resin is a mixture of different thermosets and thermoplastics and for real-world samples, the formulation is proprietary information. Table 11.4 shows the product yield for the pyrolysis of polyurethane, polyester, polyamide and polycarbonate in a fluidized-bed pyrolysis reactor [9]. 

During the 1930s it expanded its urea-based products into thermoset plastics, including the successful Formica brand of molded products. Its Lederle Laboratories extended into the production of diphtheria, tetanus, and typhoid vaccines. During World War II this subsidiary was more involved in... 

Minerals, such as calcium carbonate, talc, silica, are quite common fillers in plastic industry. They, often at abont 6-15 cent/lb, replace a much more expensive plastic, increase stiffness of the filled product, and render the plastic more flame resistant. The world filler market for plastics is dominated by carbon black and calcium carbonate. Of abont 15 billion pounds of filler in America and Europe, about half the filler volume goes into elastomers, a third into thermoplastics, and the reminder into thermosets. About 15% of all manufactured plastics contain fillers. 

Carbon fibers can be produced from a wide variety of precursors in the range from natural materials to various thermoplastic and thermosetting precursors Materials, such as Polyacrylonitrile (PAN), mesophase pitch, petroleum, coal pitches, phenolic resins, polyvinylidene chloride (PVDC), rayon (viscose), etc. [42-43], About 90% of world s total carbon fiber productions are polyacrylonitrile (PAN)-based. To make carbon fibers from PAN precursor, PAN-based fibers are generally subjected to four pyrolysis processes, namely oxidation stabilization, carbonization and graphitiza-tion or activation they will be explained in following sections later [43]. 

Phenol-formaldehyde was reported as the first commercially synthetic polymer (1899) which was introduced as BakeliteT by Baekeland in 1909. This was the period which marked the dawn for the production of commercial synthetic thermosetting polymers. Other advances in the field included the discovery of urea-formaldehyde resins in 1884 and the beginning of their commercialization as Beetle moldable resin in 1928, followed by thiourea-formaldehyde (1920), aniline-formaldehyde (Cibatine by Ciba, 1935) and melamine-formaldehyde (1937) moulding powders. The year 1909 marked the discovery of epoxy compounds by Prileschaiev, which were not used until World War 2. The first thermoset polyesters, invented by Ellis, date back to 1934 and in 1938 was reported their first use in the forms of glass-reinforced materials [1]. 

Although this chapter has touched on many aspects of thermoset part design and processing, it has not covered a myriad of special considerations that may arise in the real world. The less-experienced part designer is advised to consult with others in the field as he or she develops part design, selects the material, and chooses the optimum process for the production requirements. 

Table 6. 1999 World Thermoset Powder Coatings Production ...

Highly filled reformulated versions of thermoplastic polyolefin (TPO), acrylonitrile-butadiene-styrene (ABS), and polycarbonate (PC)/ABS blends are found in bumper applications around the world. Today, TPO dominates this market worldwide. Other than these polymers and blends, thermosets often enter into this market as reaction-injection-molded (RIM) products. 

While the early 1930s and World War II saw the development of the newer family of thermoplastics, thermosetting plastics were still the most important until the early 1950s, as Table 3 shows [35]. Of the total production of 330,000 tonnes in 1968, 73% was accounted for by the older materials phenol-formaldehydes (PFs), urea-formaldehydes (UFs), and alkyds. The remaining 27% was accounted for by the newer materials such as unsaturated polyesters (UPs), epoxides (EPs), and polyurethanes (PUs). 

Perhaps the greatest advances in materials made during the twentieth century have been in polymer science. The invention of nylon in 1938 by Wallace Carothers at Dupont laid the foimdation for the synthetic fiber industry and the miracle fabrics we enjoy today. Leo Baekeland developed a method for producing bakelite (phenol formaldehyde), the first thermosetting plastic, in 1909. This material was the forerunner of the enormous plastics industry that developed during and after World War 11. Other polymer products from S5mthetic rubber to adhesives and coatings have found their way into virtually every aspect of our present day lifestyle. 

---