Introduction to Polymer, Elastomer and Synthetic Fibre, Polymerisation (Part - 1) | Chemical Technology - Chemical Engineering PDF Download

Introduction to Polymer, Elastomer and Synthetic Fibre, Polymerisation

Polymers were accidentally synthesized, however as more and more applications were later discovered. Polymers have penetrated into all fields of application and in volume of around 205 million tonnes per annum including standard polymers, engineering resins, elastomers, duromers, fibers and textiles, dispersions. Polyolefins (LDPE, LLDPE, HDPE and polypropylene) are by far the largest group of thermoplastic polymers. Polypropylene resins along with polyester resins (PET), are one of the fastest-growing categories of commodity thermoplastic resins in the world. The United States and China now represent more than 15% and 22%, respectively, of world polypropylene consumption. Polymers have penetrated into all fields of application and in volume of around 205 million tonnes per annum including standard polymers, engineering resins, elastomers, duromers, fibers and textiles, dispersions. Amongst the plastics, thermoplastic market represents approximately 10 percent of global chemical industry. World polymer demand in 2010 was 280 million tones. Type of polymer and there global demand is shown in Figure M-VIII 1.1. Typical consumption of plastic by industry and as polymer is shown in Figure M-VIII 1.2.

Polyolefins are by far the largest group of thermoplastic polymers. As per CMAI 2003, polyolefins (LDPE, LLDPE, HDPE and polypropylene) represent the largest segment of the global thermoplastics business at approximately 88 million tonnes (about 62percent of the total market in 2002). Major success factors for polyolefins are: easy accessible, reasonable raw materials (oil & natural gas based), low production cost by modern energy saving and non polluting processes, resources saving products, environmentally harmless products, energetically exploitable products after usage, broad product portfolio, and tailor made products. Various type of polymer and their use is illustrated in Figure M-VIII 1.3.

Polyvinyl Chloride (PVC) is the second largest commodity thermoplastic in the world, after the polyethylenes. According to global production and consumption of polyvinyl chloride (PVC) in 2010 was approx. 34 million metric tons. Global consumption of polyethylene in 2009 was approximately 64 million metric tons. Global capacity utilization was 80% in 2009, down from 82% in 2008. Average global utilization of polyethylene rates are expected remain under 80% during the next five years, gradually increasing to the high-80s by 2019. World polyethylene per capita consumption is targeted to grow from 9.0 kg - 11.0 kg from 2001-06. High density PE (HDPE) accounted for around 45% of global polyethylene consumption in 2009, followed by linear low density PE (LLDPE) and low density PE (LDPE). Figure M-VIII 1.4 show the use of plastic in different fields.

Figure M-VIII 1.1: World Total Polymer Demand in 2010 approx: 280 million tones 

Courtesy: CAMI Consulting, 2010 

Figure M-VIII 1.2: Plastic Consumption, according to Industry and Polymer 

Figure M-VIII 1.3: Various Types of Polymer and their Application 

Figure M-VIII 1.4: Uses of Plastic

Global demand for polymers is estimate to increase at 5% per annum to reach 227 MMT by 2015. Polymer demand in India is expected to grow at 13-14% p.a. and will account for 9% of global polymer demand by 2015. The total polymer demand in India by 2015 is estimated to be around 22 MMT. Table M-VIII 1.1 gives the detail of India share in global polymer demand 

Table M-VIII 1.1: India’s share in The Global Polymer Demand by 2015 

 Source: Dept of Chemicals& petrochemicals, GOI, IMaCS Analysis 

Plastic Industry in India 

Consumption – 4.8 million tons/annum

Over 96% (4.6 million tons) is accounted for commodity plastics

Per capita consumption, 4.8 Kg as against world average 20 Kg.

Projected demand in 2010-11- 8.5 million tons (Growth rate @ 15%).

Raw material prices are influenced by international demand and supply of crude oil. 

Classiofiaction of Polymer: Natural and synthetic polymers could be classified in several other ways, viz., organic and inorganic; on the basis of physical properties as plastomers (plastics), elastomers (elastic) and fibrous (fiber); on the basis of response to temperature as thermoplastics and thermosets. Various ways of classification of polymer is given in Figure M-VIII 1.4: Polymers or resins are generally classified in two broad categories–Thermoplastic and Thermosetting. Repeated heating and cooling doesn't alter the chemical nature of thermoplastic while Thermosets are permanent setting resin and once solidified these materials may not be reshaped or formed by applying heat. Thermoset plastic are stronger than thermoplastic. 

Thermoplastics Plastics: Thermoplastics are organic chain polymers that usually become soft when heated and can be molded under pressure. Thermoplastic resin are linear or branched chain polymers with little or no cross linking. Major thermoplastic demand in world is shown in Figure M-VIII 1.5. Various thermoplastic resins are polyethylene, polypropylene, PVC, polyvinyl acetate, poly methylmethaacrylate, poly carbonates, polystyrene [Table M-VIII 1.2] 

Figure M-VIII 1.5: Breakup- World Major Thermoplastics Demand Estimates-2007(183 Million MT) 

Source:Technical EIA Guidance Manual, Project Sponsored by the Ministry of Environment and Forests 

Table M-VIII 1.2: Major Thermoplastic polymers  

Polycarbonates	PC	Polyester		190 (Tg)	1.2
Polyacetals		Polyethers		181(Tm)

 

Thermosetting Resins: Thermosetting Resins are a network of long chain molecules that are cross-linked which gives the polymer a three dimensional, infusible structure. They poloymerise irreversibly, under heat or pressure to form hard, rigid mass. Various thermoset resins are Phenol-, urea-, melamine- formaldehydes, polyurethane, alkyd resins, epoxy resins etc. Various Thermo set resins are given in Table M-VIII 1.3. 

Table M-VIII 1.3: Various Thermo Set Resins 

S. No	Name	Family	Formula
1.	Polyurethane	E steramide
2.	Alkyd resi ns	Polyester
3.	Unsaturated polyesters	Polyester
4.	Epoxy resi ns	Polyether
5.	Phenol formaldehyde	Phenolic
6.	Urea formaldehyde	Urea
7.	Melamine formaldehyde	Melamine