Ptt Seminar Work

PTT–A New Member in n Polyester Family(A New Fibre) By : Piyush Takkar [Pick the date] Table of Contents 1. Introduction…………………………………………………………………… 1 2. Polymerization……………………………………………………………….. 2 2.1 1,3-PROPANEDIOL MONOMER………………………………………. 3 2.2 THE POLYMERIZATION STAGE………………………………… 3 2.3 SIDE REACTIONS AND PRODUCTS…………………………… 8 2.4 Environmental benefits of PTT fibre……………………….. 10 3. PTT as a Textile Fibre……………………………………………………… 10 3.1 FIBRE STRUCTURE…………………………………………………… 10 3.2 FIBRE CHARACTERISTICS………………………………………… 11 3.3 Comparison with different fibre………………………………. 12 4. CHEMICAL PROCESSING OF PTT……………………………………….. 15 4.1. TECHNOLOGY OF DYEING………………………………………… 16 5. APPLICATIONS………………………………………………………………… 20 6. PTT for nonwovens…………………………………………………………. 22 7. HEALTH AND SAFETY……………………………………………………….. 23 8. CONCLUSION…………………………………………………………………… 24 They compared the mechanical properties of the three polyester fibers(PET. This led to a period of active research in PTT polymerization and applications. These two properties are very desirable and are valued for making soft. In a 1971. INTRODUCTION Poly(trimethylene terephthalate) (also referred to as “3GT” or “PTT” or “PTMT”) is a futuristic synthetic fibre with its unique spring -like molecular structure possessing the favourable properties of both polyester and nylon. 1. flooring. was not readily available and was therefore not suitable as a raw material for commercial polymers. and was therefore more suitable than PET for making fiberfill and carpets. Shell later exited the PDO business and Degussa assumed its manufacturing. In the early 1970s. the Shell Chemical Company. Interest in PTT revived in the late 1980s when both Shell and Degussa made breakthroughs in two different PDO manufacturing technologies. the fiber industry had been aware of PTT having desirable properties for fiber applications. It was first synthesized by Whinfield and Dickson nearly 60 years ago.1. ‘‘Fiber Industries’’ found PTT fiber have a lower modulus. a producer of PDO via the acrolein route. For a long time. stretch-fabrics with good hand and touch. Thus. explored the commercial potential of PDO and PTT by sampling PDO with several fiber companies.3-propanediol (PDO). and found PTT indeed had a better tensile elastic recovery and a lower modulus than both PET and PBT. better bending and work recoveries than PET. PTT was still an unfavorable polyester for business atmosphere at that time so further development of PTT was stopped. while having its own stretchiness. PBT and PTT). Despite making significant progress in lowering PDO manufacturing cost. it was a challenge for chemical and fiber companies to develop breakthrough technologies to lower PDO cost and to commercialize PTT. It is a newly commercialized aromatic polyester and has recently received much attention as a polymer for use in textiles. Degussa was able . and for resilient carpets. It is also readily compatible with natural and synthetic fibres thanks to its unique soft texture. packaging and other end uses. PTT has remained an obscure polymer until recent times because one of its monomers. leveraging their core competencies in hydroformylation technology and EO feedstock. and built a 160 mm lb PDO plant in Geismar. Louisiana. Shell announced the commercialization of PTT. It is also called 3GT in the polyester industry.while DuPont’s trademark is Sorona© 3GT. The number preceding G stands for the number of methylene units in the glycol moiety. PTT finally joined PET and PBT. to produce PTT using PDO obtained from Degussa while they and Genecore International collaborated to develop a potentially cheaper biological route for making PDO through glycerol fermentation. with G and T standing for glycol and terephthalate. This was followed by DuPont announcing the retrofitting of an existing polyester plant in Kinston. respectively. . and became a commercial reality. 2. The chemical structure of Poly(trimethylene terephthalate) Shell Chemical Company’s PTT is trademarked as Corterra© polymer. North Carolina. More than half a century after its synthesis. POLYMERIZATION PTT is made by the melt polycondensation of PDO with either terephthalic acid or dimethyl terephthalate. In 1995. Shell developed an alternate synthesis route by hydroformylating ethylene oxide (EO) with a combination of CO and H2 synthesis gas.to lower the cost of manufacturing PDO via the acrolein route and improve its purity to levels suitable for polymerization. There are two commercial synthesis routes The first of these is the traditional route. Shell uses EO as a starting raw material. In the second process. . via the hydration of acrolein under pressure at 50°C into 3-hydroxypropanal (3-HPA) using an acid catalyst.1 1. This process is still under development by Du Pont and Genecore International. A new route with the potential of further lowering PDO cost is the enzymatic fermentation of glycerol and alcohol. 2.3-PROPANEDIOL MONOMER PDO also called trimethylene glycol. new strains of engineered bacteria have improved the yield and selectivity of the process to the point where this route is ready for pilot plant scale-up. is a colorless. The 3-HPA intermediate is then hydrogenated into PDO by using Raney nickel catalyst.2. With advances in biogenetic engineering.2 THE POLYMERIZATION STAGE PTT is melt polymerized by either the transesterification of PDO with dimethyl terephthalate (DMT) or by the direct esterification of PDO with purified terephthalic acid (PTA). clear liquid with a boiling point of 214°C. The aqueous 3-HPA solution is then concentrated and hydrogenated to produce PDO. EO is first hydroformylated into 3-HPA by using a combination of CO and H2 synthesis gas with cobalt catalysts. Because TPA has a melting point of >300°C and poor solubility in PDO.The process is similar to that for PET but with major differences. Instead of cyclic trimer. catalysts and additives for both the DMT and TPA processes. PTT produces a lower-melting cyclic dimer by-product. 5. and requires special handling and treatment. direct esterification is preferably carried out in the presence of a ‘heel’ under a pressure of 70–150 kPa and at 250–270°C for 100–140 min.2 shows the direct esterification reaction scheme. Acrolein is toxic and is a very strong lachrymator. which forms tetrahydrofuran byproduct in PBT polymerization. acrolein and allyl alcohol are the volatile byproducts of PTT production. Because of PDO’s lower reactivity. pelletizing and solid state treatment. 3. more active catalysts based on titanium and tin. it requires special consideration in polymerization. purposely left in the reaction vessel from a previous batch to . while Fig. Table 1 summarizes the reaction conditions. PDO is difficult to cyclize into oxetane because of the high ring strain. 2. are used to polymerize PTT. Only the TPA process will be described below. However. A heel is an oligomeric PTT melt with a degree of polymerization (DP) of 3 to 7. Direct esterification of PDO with TPA is a more economical route than transesterification with DMT. Compared to 1. The generation of acrolein is to be expected since it is one of the starting raw materials for making PDO. Oxetane was not found in the byproduct analysis. PTT has different side reaction products. 4. Because of its higher melt degradation rate and a faster crystallization rate. it is also more difficult technology to implement.4-butanediol. Instead of the acetaldehyde produced with PET. as follows: 1. PTT is polymerized at a much lower temperature between 250 and 275°C. which would discolor PET. improve TPA solubility and to serve as a reaction medium. Polymerization of PTT by direct esterification of PDO with TPA using the heel process . The esterification step is self-catalyzed by TPA. . . different and involves two mechanisms.0 dL/g. 40–50% of the oligomeric melt is transferred to the polymerization vessel.After reaching the desired DP.7–0. 2. Some of the more important ones are as follows:  McClafferty rearrangement of the ester moiety (Figure 11. To obtain higher-molecularweight PTT with an IV >1. or some combinations of the two catalysts. The carbonyl unit abstracts a β-methylene hydrogen through a six-member cyclic transition state. The solid-state treatment prevents the polymer from becoming yellow or degraded by prolonged melt polymerization to reach the high IV. PTT shares several similar thermo-oxidation degradation mechanisms with PET. however. This post-condensation process also helps drive off volatile byproducts.3). The reduction of cyclic dimer during post condensation is through sublimation. degradation was decomposition-controlled. PTT has a similar thermogravimetric weight loss profile to that of PET with one main decomposition step. At higher temperatures. and the chains fragment with carboxyl and vinyl ester end groups.3 SIDE REACTIONS AND PRODUCTS PTT melt undergoes several side reactions during polymerization and melt processing. thus reducing the amount of residual acrolein and cyclic dimer in the final polymer. Under an inert atmosphere. melt-polymerized chips are solid-state polymerized at 180–210°C under nitrogen. the molecular weight distribution is broadened. Titanium butoxide (50–150 ppm) or dibutyl tin oxide catalyst (100–250 ppm). A thermogravimetric analysis (TGA) scan of PTT does not show significant weight loss up to 280°C. the rate increases and decomposition changes to a diffusion-controlled process. is added to catalyze polymerization at 260–275°C. Degradation in air is. Further scission of the vinyl ester group generates allyl alcohol.15 kPa is applied to remove the condensed water so as to drive the reaction until the polymer reaches an intrinsic viscosity (IV) of 0.9 dL/g. A vacuum of <0. The chips are also more crystalline and tend to be more brittle. At about 300°C. . however. which in the presence of oxygen is oxidized to acrolein. DPG formation is more severe in the acidic TPA process. PDO dimerizes into dipropylene ether glycol (DPG) which incorporates into the PTT chains as a copolymer. Proposed PTT thermal degradation mechanism through the Mc-Clafferty rearrangement and the formation of acrolein and allyl alcohol. PTT forms its cyclic dimer.  During polymerization. which has a melting point of 254°C. Instead of cyclic trimer. The incorporated DPG lowers the polymer’s melting point and affects fiber dye uptake. ‘Back-biting’ of the growing polymer chain generates cyclic oligomers. so interfering with fiber spinning process. using higher purity PDO and controlling the polymerization conditions . The above side reactions can be suppressed to various extents by adding antioxidants and phosphites. . The amount of cyclic dimer in the final polymer is preferably below 3 wt% because it tends to sublime and deposit as needle-like crystals on the spinnerette die face. If we analyze macromolecular structure of PTT. hard.6.1. . there are no additional chemical treatments used for stain resistance. and extremely tough. 3. Further. Energy savings is also part of the environmental story with PTT offering a 30 percent savings over nylon 6 and a 40 percent savings over nylon 6. Environmental benefits of PTT fibre Producing PTT fibre uses 30 per cent less energy and reduces green house gas emissions by 63 percent compared to the production of an equal amount of nylon 6. we can notice the structural and substantial differences with the fibers of PET.2. lower emissions. Less energy. FIBRE STRUCTURE PTT is crystalline.4. strong. PTT as a Textile Fibre 3. no added chemical treatments. lose their shape easier and as easier go back to their original shape. and is noticeably softer than polyester. it is said to resist bleaching even better than polyester PET. and it easily removes oily spots and soils (petroleum. combining the rigidity. The molecular structure of a zigzag shape can translate tensile or compressive forces at a molecular level to bending and twisting of bonds rather than simply stretching.The unique molecular structure of PTT features a pronounced “kink” as shown above. 3. This is reason for better stretch recovery characteristics than other traditional polymer. even in concentrated form (6 percent).. are easier to be cleaned and dry quickly.g. which gives serious beneficial properties to PTT compared with PET. As regards to other synthetic fibres. such as sodium hypochlorite. PTT FIBRE CHARACTERISTICS PTT is an advanced polymer that can be spun into fibres. Colour fastness of PTT is superior to polyester and Type 6 nylon and comparable to Type 6. They also are better dirty-resistant. PTT has a very desirable property set. Fabrics produced from PTT fibres and yarns clean easily and have superior durability. . and light and sun fading. nitrogen dioxide. is achieved by the polymer itself. PTT is also resistant to strong oxidizing bleaches. 6 nylon when subjected to a wide range of tests including high concentrations of ozone. while a some what subjective evaluation. propylene glycol). which is analogous to the tensile behavior of a coiled spring compared with a straight wire. PTT ones are easier to be dyed. strength and heat resistance of poly(ethylene terephthalate)(PET) with the good processability of poly(butylene terephthalate)(PBT). PTT is oleophilic. softness. and performs similarly to polyester PET and olefin. In fact. PTT’s hand. bulk.2. animal. and comparable to nylon fibre. vegetable) using dry solvent spotters and cleaning additives (e. The fibres and yarns have a unique combination of properties including stretch and recovery. keep vivid colours longer. stretch and recover better. Compared with other synthetic fibres like nylon and acrylic. dye easier. PTT fibres resist staining. clean easily and dry quickly.4 7 254 59 1.35  Glass transition point 51 3. retain vibrant colours longer. garments.4 15 230 54 1.34 25 . Whether used in carpet.5 38 23 40 1.4 30-38 97 29 1.4 Shrinkage at boiling (%) 14 Melting point (°C) 230 Heat distortion temperature at MPa(°C) 65  Specific gravity 1.38 0.40 69 3.3.31 0.3.7-4. PTT fibres feel softer. Comparison with different fibre PTT fibre combines the best properties of nylon and polyester. PTT fibres look better longer. More important. home furnishings or automotive fabrics.34 Moisture regain(%) 0.4-3. Properties of poly(triethylene terephthalate) PTT PET PBT          Tensile strength (cN/dtex) 3.7 Elongation at break (%) 36-42 Initial modulus (cN/dtex) 23 Elastic recovery at 20% elongation 88 3 Density (g/cm ) 1. . Comparsion of Stain Analysis on different carpets : . and most importantly. Carpets have nylon-like wear performance without the need of chemicals stain treatments and complicated cleaning procedure. easy care.Carpets made from PTT fibres combine     luxurious feel inherent stain resistance excellent wear performance anti-static performance. desizing and scouring may not be needed. preheat set and softening are optional and final heat-set is deemed necessary. Relaxation and preheat set on fabrics may or may not be applied. a heat-set process at an identified temperature is required. desizing and scouring may be generally required for the woven PTT fabrics.PTT Polymer chemical resistance : 4. For knitted fabrics. sizing. In addition. A fiber softening process and a fabric softener may be applied to the dyed and heat-set fabric and thereafter. generally. CHEMICAL PROCESSING OF PTT Like normal polyester fabrics. In order to obtain a power stretch fabric. a final heat-set (at temperature lower than or equal to . previous heat-set one) is used. Poly(triethylene terephthalate) combines properties of both. 4. although the later is now dyed under pressure at 130°C to avoid using carrier. TECHNOLOGY OF DYEING Because of the low Tg. KNITTED FABRICS Scouring (optional) Mecerization (optional) Preset (T1) Dyeing Heat Set (T2) Final Heat Set(T3) Softening An outline of the dyeing and finishing procedure for PTT knitted fabrics WOVEN FABRICS Scouring Mecerization (optional) Preset (T1) (optional) Dyeing Heat Set (T2) Final Heat Set(T3) Softening An outline of the dyeing and finishing procedure for PTT woven fabrics Note : Conditions for scouring were as follow – Na2CO3(2 g/l). It gives excellent colourfastness and also possesses natural stain resistance. PTT is therefore a more environmentally friendly polymer than PET in this regard.1. time 20 min. detergent LS (2 g/l) temperature 90-100°C. . The resulting fabrics should have good stretch and soft hand-touch and may be better than the greige fabrics. carrier or high pressure is required in the case of dyeing of PTT fibre. No pH adjustment. PTT fibers and fabrics are dyed at atmospheric boil without the need of a carrier. PET and nylon in terms of dyeability. Exact holding time used during the dyeing depends on temperature profiles used in the production. giving designers more choices for textile colors. majority of the dye uptake takes place within 20 minutes.PTT is dyeable without a carrier at boiling temperatures under atmospheric conditions because of the open molecular structure. But lower K/S values have been obtained due to opaqueness of the fabric. It is known that various dyeing and finishing procedures have been employed in the textile industry. Sample dyeing cycle and temperatures for PTT fibers using low energy disperse dye 95-100°C 20-40 min 1°C/min 60°C 2-3°C/min 3-5°C/min Drop-Rinse-Scour-Rinse Ambient For PTT. which is 10-20°C higher in the case of PET. . Higher holding time does not increase the dye uptake value. Better dye penetration results in better colour-fastness properties like washing rubbing fastness. yielding a uniform colour with good fastness. The procedures depend on the equipment used and types and materials of fabrics. the temperature that affects the levelness starts at 60 C. PTT allows for additional tonal shades with pressure dyeing. In the holding time indicated in the graph. Disperse dyes work best on PTT fibres. shade depth and dyeing temperature. providing colour fastness comparable to nylon with to nylon with select dyes.  Some results and comparsion:  For colorant C. Effect of dyeing temperature on PTT and PET fiber shade depth. disperse blue 139.I. the variation in absorption of colorant with coloring temperature for PTMT and PET . disperse red 60.I. disperse blue 139 with coloring temperature for PTMT and PET  For colorant C.I. the variation in absorption of colorant with coloring temperature for PTMT and PET . The variation in depth of penetration of colorant C. sheets and pillow cases. Carpets made with PTT fibres offer a breakthrough in the combination of stain resistance and durability. The application of PTT in the textile industry include filament yarns. swimwear. However. and are less expensive and much easier to work with than spandex. They have nylon-like wear performance without the need for chemical . and bulked continuous filament yarns(BCF) for carpets. APPLICATIONS Fabrics made from PTT fibres not only offer easy-care and stretch. beautiful fluid drape and rich brilliant colours.Main achieved environmental benefits: The following environmental benefits are achieved in the dyeing pocess compared to standard polyester fibres (PET type):   emissions of carriers in the workplace and in the environment are completely avoided. remarkable softness. In apparel it can be used in casual. but a combination of features that include inherent stain resistance. PTT fibres dye well at low temperatures. There also are benefits for textile manufacturers i. draperies. staple fibre. PTT fibres can be used in apparel as well as home furnishing. active wear and inner wear and on the other hand in home furnishing carpets.e. PTT fibres are best to manufacture the carpets. wall coverings and upholstery can be made by PTT fibres. 5. lasting durability for longer wear. a lower amount of energy is consumed compared with PET dyed under high-pressure-high-temperature (HT) conditions (PTT is dyed atmospherically at 100°C with excellent dye exhaustion and colourfastness). blend well with other fibres. PTT fibre's stain resistance offers an ease of maintenance and reduced need for replacement. . iodine and hot coffee. intimate apparels. some of these commercial products: (a) Solo™ soft. Moreover. stretch casual wear by Asahi. Most stains. stain resistance and low static generation provide values over currently used materials in some market segments. recovery. Within a short period of time since the polymer’s commercialization. utilizing the easy dyeing. (b) cut-pile carpet marketed by Shaw Industries.  ready-to-wear. active wear. can bere moved with hot water and are dry within a few hours.  One of the most recent applications is sewing thread which will endow clothing products with added values by appropriate extensibility. and inner linings where stretch-recovery. including mustard. and dimensional stability. hand and drape are the key attributes.stain treatments and complicated cleaning procedures.  carpets where resiliency. softness.  automotive and home upholstery. stain resistance. newness retention. and stretch-recovery properties. PTT ready-towear stretch apparels and resilient floor coverings have already appeared in the market. or the slower speed machines by Reifenhäuser. while retaining the outstanding resistance to gamma radiation. non-wovens. PTT for nonwovens  From staple fibers Blends of PTT staple with other fibers such as PET. Other applications include synthetic leathers.Other potential applications of PTT are in monofilaments. 6. engineering thermoplastics and molded goods. The soft hand-touch and high bulk are the features of the PTT based nonwovens. Fabrics made with PTT monofilaments are use in papermaking machines because this combines the chemical resistance of a polyester and the resiliency of the less chemical resistant nylon. Shell is developing the spunbond as carpet backing for PTT. The benefit is to have an all PTT based carpet system for easiness in recycle stream. PTT non-woven fabric shows better dimensional stability and is softer than PP. nylon and polypropylene have been or may be made into nonwovens through needle punch and hydroentanglement. films. The Reifenhäuser line (slower speed) gives a very dimensionally stable fabric if processed with the correct calender settings. Damage from gamma radiation is a major problem with the use of . Fabrics made from the higher speed process are soft and drapeable. flexible transparent film for packagings and zip fasteners.  From spunbonds PTT based spunbond nonwovens have been made using either the higher speed machine made by Hills/Ason process. 7. took the responsibility of product stewardship. forming more of an “unbounded spunbond” sort of structure. Conjugated fibers from PTT with other materials such as nylon.polypropylene in medical fabrics. When thicker structures were formed. and registered the polymer on the chemical inventory lists in several . Conjugated PTT-PET side-by-side SDY may exhibit high bulk due to the difference in shrinkage after stretch in the solid state for the two materials. and not at all soft. HEALTH AND SAFETY Since PTT is a new commercial product. they were somewhat boardy. The 12. PTT may be used as the binder for the PET-PTT conjugated spunbond or meltblown web in nonwoven application. the Shell Chemical Company. The PTT based sea-and-island fibers may be made into ultra-fine denier fibers for application such as artificial leathers. This may be due to the heat in the fibers still present when they fibers are packed onto the collection drum. The fabric was characterized by random and uniform web formation. while softness and extrusion in a spunbond process is a major weakness of PET. The PTT meltblown sample was somewhat different in nature from PP meltblown. a relatively thin nonwoven.2 g/ m2 meltblown sample is quite soft and drapable.  From meltblown A melt temperature between 260 and 275°C was used to produce PTT fabric samples from the meltblown process. One may get a more bulky web because of the differential shrinkage during web forming. PP and PE are being studied. It does not appear to form the same kind of web as PP.  From bicomponent (conjugated) fibers PTT based sheath core and side-by-side spunbonds have been produced.2 g/m2. as the company which first introduced it to the market. The basis weight was 12. 1 ppm. Among these. promotion by major industry players. When PTT is exposed to high heat such as during drying and melt processing. Shaw and DuPont. PTT does not hold a significant carpet market share. while the short-term exposure limit for 15min is 0. It can also irritate lung and respiratory tracts. PTT polymer is also a good candidate as a fiber in nonwoven applications. it releases acrolein. no other fibre can beat PTT. Ultra micro-denier artificial leather based on PTT polymer is also possible. The effects are acute and do not have cumulative long-term effects. Conclusion The PTT fibre is considered to be the most important fibre of the after-polyester period. and affect breathing. As a high molecular weight polymer. The PTT based nonwovens can also be made from spun-bond and meltblown. As far as long-term performance is concerned.3 ppm. . however. the resistance to gamma radiation and softness are the two major benefits in nonwoven articles based on PTT polymers. Again. may change that. allyl alcohol and cyclic dimer by-products. 8. PTT is biologically inactive and requires safe handling like many other commercial polymers. Therefore. It is the first significant new material in the textile and carpet industry for some time. At this point. It provides manufacturers with a wider range of options for new products than they have now. acrolein is of special concern because it is a very strong lachrymator. adequate ventilation must be provided to avoid acrolein exposure.countries. such as Mohawk. The US Occupational Safety and Health Agency industrial hygiene guidelines gave the time-weighted exposure limit of acrolein over a period of 8 h as 0. PTT based nonwovens can be produced from staple fibers (pure or blends) through the techniques of needle punch and hydroentanglement. Fabrics made with PTT fibres have great appeal in the fast-growing stretch market. Today’s market demands beauty. Designers. environment and value when it comes to products.html 15. 11. beauty is simply not enough. www.pdf jit.com/articles/FAdetails.com/6495254 www.The mantra of ‘Performance PLUS environmental benefits’ is evident for PTT fibre in carpet applications.freepatentsonline.blogspot. Modern polyesters 2003 (www. 4.asp www.isotextile. 10.com/cgi/content/refs/31/3/159 http://www. performance and sustainable solutions. http://www.jp/j-east/article www.int/pctdb/en/wo.gov/hq/lab/fsc/backissu/july2001/houck.jsp www.gov/os/statutes/textile/info/PTTGenAppRev8-30-06.intota.swicofil.html en.asp?id=1240 14. 2.com).com/doc/78810135/New-Fibres-for-Home-Textile-PTTTriexta-Fibre# 12.com/polytrimethyleneterephthalate.org/wiki/Polyethylene_terephthalate www.technica. 5. 7.ftc.springerlink. In today’s competitive environment.com/index/AV1DWAWEDCQPHTC3. 6. 9. 3. architects and managers are looking for………… References 1. PTT fibre in commercial carpet applications provides what designers.pdf 13.wikipedia.html www.swicofil.com/ptt.wipo.sagepub.com/multisearch.net/NF/NF1/eptt.pdf . 8. www. and facility managers demand more in terms of performance. architects.indiantextilejournal.scribd. http://www.fbi.html sciencelinks.