Poly trimethylene terephthalate PTT

The expected species are therefore allene and allyl alcohol. 

Allyl alcohol has a bp of 97 °C, and is thus considerably less volatile than any of the above. In the presence of acid catalyst, allyl alcohol can isomerise to propionaldehyde, even though even this acid-catalysed reaction is much slower than the isomerisation of vinyl alcohol to acetaldehyde. There is thus a distict posibility that allyl alcohol can react with any available acid end group to reform the unsaturated 

Early pyrolysis-mass spectroscopy [14] and pyrolysis-gas chromatography [16] studies compared the breakdown of PET, PTT and PBT and, while providing no clear-cut reaction pathways, showed that all three polyesters appeared to thermally degrade via the same mechanism. 

As alluded to earlier, PTT was initially synthesised at the same time as PET, but was not commercially developed at the time because of the high cost and low purity of the 1,3-propanediol then available. With the discovery of better, more economic ways of manufacturing this starting material, further work on the degradation mechanism proceeded in the 1990s. 

At about the same time as the above, workers at Degussa AG and Zimmer AG were investigating large-scale production of PTT [74]. They noted that small amounts of acrolein and allyl alcohol were produced during polymerisation (approximately 0.2-0.3% of each) and stated that the mechanism of formation of allyl alcohol was identical to the formation of vinyl alcohol from PET. It was also stated that A convincing reaction mechanism for the generation of acrolein has not yet been established. The authors noted the level of cyclic oligomers in as-synthesised PTT was between 1.6% and 3.2% (c/PET approximately 1.7% PBT approximately 1.0%). 

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TABLE 2.11 Typical Properties of Unfilled Polyethylene terephthalate) (PET), Poly(trimethylene terephthalate) (PTT), and Poly(butylene terephthalate (PBT) Solid-State Polyester Resins... 

Poly(trimethylene terephthalate) (PTT) is a polymer with very useful properties. As a textile fibre it has excellent softness, stretch and recovery. As a resin it has excellent barrier properties. Developed over 60 years ago, PTT has not been very widely used compared to poly(ethylene terephthalate) (PET) as one of the key monomers 1,3-propanediol (PDO) has been expensive. 

Poly(trimethylene terephthalate) (PTT) is a newly commercialized aromatic polyester. Although available in commercial quantities only as recently as 1998 [1], it was one of the three high-melting-point aromatic polyesters first synthesized by Whinfield and Dickson [2] nearly 60 years ago. Two of these polyesters, polyethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT), have become well-established high-volume polymers. PTT has remained an obscure polymer until recent times because one of its monomers, 1,3-propanediol (PDO), was not readily available. PDO was sold as a small-volume fine chemical at more than 10/lb., and was therefore not suitable as a raw material for commercial polymers. 

It should be taken into account that all of the aspects described above are of a general nature and therefore more or less valid for any kind of industrially relevant polyester resin. Upon closer examination, the experiences gained with PET are particularly applicable to poly(butylene terephthalate) (PBT), poly(trimethylene terephthalate) (PTT) and polyethylene naphthalate) (PEN). These polymers have gained major industrial importance as a result of a number of different properties in comparison with PET. 

The newest commercial polymer to join the polyester family is poly(trimethylene terephthalate) (PTT) which is being targeted at fibre applications (Chapter 11). It is sold under the Corterra trademark by Shell. After packaging, the single largest use for polyesters is for fibre applications such as clothing, textiles and non-wovens. The technology of polyester fibre formation is described in Chapters 12 and 13. 

DuPont and Shell have developed a new polyester, poly(trimethylene terephthalate) (PTT) (structure 19.38) that is structurally similar to PET, except that 1,3-propanediol (PDO) is used in place of ethylene glycol. The extra carbon in Sorona allows the fiber to be more easily colored giving a textile material that is softer with greater stretch. Further, it offers good wear and stain resistance for carpet use. The ready availability of the monomer PDO is a major consideration with efforts underway to create PDO from the fermentation of sugar through the use of biocatalysts for this conversion. Sorona and Lycra blends have already been successfully marketed. Sorona is also targeted for use as a resin and film. 

Hydroxypropanal. 3-Hydroxypropanal can be formed by fermentation of glucose and is thus an attractive starting material for production of 1,3-propanediol, which can be polymerized with /ere-phthalic acid to produce poly trimethylene terephthalate (PTT). PTT is used in the fibers industry in the production of stain resistant carpets etc. 

Propanediol (1,3PD) is also undergoing a transition from a small-volume specialty chemical into a commodity. The driving force is its application in poly (trimethylene terephthalate) (PTT), which is expected to partially replace polyethylene terephthalate) and polyamide because of its better performance, such as stretch recovery. The projected market volume of PTT under the trade-names CORTERRA (Shell) and Sorona 3GT (Dupont) is 1 Mt a-1 within a few years. In consequence, the production volume of 1,3PD is expected to expand from 55kta-1 in 1999 to 360 kt a-1 in the near future. 1,3PD used to be synthesized from acrolein by Degussa and from ethylene oxide by Shell (see Fig. 8.8) but a fermentative process is now joining the competition. 

There have been many efforts for combining the atomistic and continuum levels, as mentioned in Sect. 1. Recently, Santos et al. [11] proposed an atomistic-continuum model. In this model, the three-dimensional system is composed of a matrix, described as a continuum and an inclusion, embedded in the continuum, where the inclusion is described by an atomistic model. The model is validated for homogeneous materials (an fee argon crystal and an amorphous polymer). Yang et al. [96] have applied the atomistic-continuum model to the plastic deformation of Bisphenol-A polycarbonate where an inclusion deforms plastically in an elastic medium under uniaxial extension and pure shear. Here the atomistic-continuum model is validated for a heterogeneous material and elastic constant of semi crystalline poly( trimethylene terephthalate) (PTT) is predicted. 

Many of these new plastics are in the polyester family. One that is getting attention is PEF, polyethylene furanoate. Avantium opened a PEE pilot plant in the Netherlands in 2011. PEF reportedly is similar to PET in performance, but is 100% biobased [10]. Polybutylene terephthalate (PBT) is available as a partially biobased plastic, from biobased 1,4-butanediol and petro-based terephthalic acid. Polybutylene succinate (PBS) is similarly made from biobased succinic acid and petro-based terephthalic acid. Poly(trimethylene terephthalate) (PTT) can be made from biobased 1,3-propanediol with, again, petro-based terephthalic acid. 

Blends of poly(trimethylene terephthalate) (PTT) and PEN are miscible in the amorphous state over a wide range of eompositions. This is evidenced by a single, composition-dependent glass transition temperature (7 ). The variation of the Tg with composition can be predicted by the Gordon-Taylor equation, with the fitting parameter being 0.57. 

Except for polymerization of hydroxyalkanoates, which is conducted in vivo, all other monomers are polymerized in vitro by chemical reactions, leading to the formation of PHA, poly(lactic acid) (PLA), poly(butylene succinate) (PBS), PE, poly(trimethylene terephthalate) (PTT), and poly(p-phenylene) (PPP) (Fig. 2). 

Abstract Poly(trimethylene terephthalate) (PTT) fibers, as a new type of polyester, are characterized by much better resilience and stress/recovery properties than poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT). PPT chains are much more angularly structured than PET and PBT chains and such chains can be stretched by up to 15% with a reversible recovery (Ward et al. 1976). These properties make PTT highly suitable for uses in fiber, carpet, textile, film, and engineering thermoplastics applications. 1,3-Propanediol (PDO), as one of the polyester raw materials for PTT, has also attracted interest. 

Fig. 9 Product life and environmental effects of poly(trimethylene terephthalate) (PTT) (Kurian 2005)...

Polyipropylene terephthalate), more often referred to as poly(trimethylene terephthalate) (PTT), was identified from research into aromatic polyesters, but was not commercialised at the time due to difficulty in obtaining pure, low-cost, 1,3-propanediol. Finally introduced into large-scale production in the late 1990s, there are great hopes for commercial application of this polymer, especially as a fibre. In general, it has properties between those of PET and PBT, but has certain unique properties of its own, including superior resilience and wear properties, giving carpets tufted with such fibres physical properties akin to the nylons, and stain resistance similar to PET. 

Despite its increasing commercial importance, studies on the UV degradation of poly(trimethylene terephthalate) (PTT) are lacking. It is currently assumed that the mechanisms of photolysis and photo-oxidation of PTT will be broadly similar to those previously discussed for PET. 

Many articles have been published on the hydrolytic degradation of poly(ethylene terephthalate) (PET) under acidic conditions [1-20] and basic conditions [21-30], but far fewer on similar degradation studies on poly(butylene terephthalate) (PBT) [31, 32], poly(trimethylene terephthalate) (PTT) [33] and poly(ethylene naphthalate) (PEN) [34, 35],... 

Poly(ethylene terephthalate), the lowest cost and most commonly used polyester, is produced using ethylene glycol (EG) and either dimethyl terephthalate (DMT) or terephthahc acid (TPA) (see Table 7.1). Processes using DMT were commercialized first, but when very pure TPA became available, TPA processes became more economical for large-scale fiber production. Poly(butylene terephthalate) (PBT), produced fi-om 1,4 butanediol and DMT, is another commercially important polyester, which is used for computer housings and many other molded products. Poly(trimethylene terephthalate) (PTT), made from TPA and 1,3 propanediol, is a relatively new commercial polyester, that shows promise for... 

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