Propanediol properties

Solvent X 1,2-Propanediol Properties of solvent pairs UNIFAC contributions 293 CH3 1 CH2 1 CH 1 OH 2... 

Propylene oxide is a colorless, low hoiling (34.2°C) liquid. Table 1 lists general physical properties Table 2 provides equations for temperature variation on some thermodynamic functions. Vapor—liquid equilibrium data for binary mixtures of propylene oxide and other chemicals of commercial importance ate available. References for binary mixtures include 1,2-propanediol (14), water (7,8,15), 1,2-dichloropropane [78-87-5] (16), 2-propanol [67-63-0] (17), 2-methyl-2-pentene [625-27-4] (18), methyl formate [107-31-3] (19), acetaldehyde [75-07-0] (17), methanol [67-56-1] (20), ptopanal [123-38-6] (16), 1-phenylethanol [60-12-8] (21), and / /f-butanol [75-65-0] (22,23). 

Plasticizers can be classified according to their chemical nature. The most important classes of plasticizers used in rubber adhesives are phthalates, polymeric plasticizers, and esters. The group phthalate plasticizers constitutes the biggest and most widely used plasticizers. The linear alkyl phthalates impart improved low-temperature performance and have reduced volatility. Most of the polymeric plasticizers are saturated polyesters obtained by reaction of a diol with a dicarboxylic acid. The most common diols are propanediol, 1,3- and 1,4-butanediol, and 1,6-hexanediol. Adipic, phthalic and sebacic acids are common carboxylic acids used in the manufacture of polymeric plasticizers. Some poly-hydroxybutyrates are used in rubber adhesive formulations. Both the molecular weight and the chemical nature determine the performance of the polymeric plasticizers. Increasing the molecular weight reduces the volatility of the plasticizer but reduces the plasticizing efficiency and low-temperature properties. Typical esters used as plasticizers are n-butyl acetate and cellulose acetobutyrate. 

Propanediol Dinitrate is a powerful and brisant expl which is less sensitive than NG, and has satisfactory stability. Following are some of its properties, as given in Refs 2, 3,4,... 

Dynamic light-scattering experiments or the analysis of some physicochemical properties have shown that finite amounts of formamide, A-methylformamide, AA-dimethyl-formamide, ethylene glycol, glycerol, acetonitrile, methanol, and 1,2 propanediol can be entrapped within the micellar core of AOT-reversed micelles [33-36], The encapsulation of formamide and A-methylformamide nanoclusters in AOT-reversed micelles involves a significant breakage of the H-bond network characterizing their structure in the pure state. Moreover, from solvation dynamics measurements it was deduced that the intramicellar formamide is nearly completely immobilized [34,35],... 

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. 

Amino-2-ethyl-l,3-propanediol commercial alkanolamine, 2 114t physical properties of, 2 114t... 

Amino-2-hydroxybenzoic acid, 2 668-669 physical properties of, 2 666t 2-Amino-2-(hydroxymethyl)-1,3-propanediol... 

Propanediol. In its racemic form, 1,2-propanediol is a petroleum-based high-volume chemical with an aimual production of over 500,0001, mostly used to manufacture the unsaturated polyester resins, yet also featuring excellent antifreeze properties. Enantiomerically pure (/ )-1,2-propanediol accumulates along two different pathways via DAHP (3-deoxy-D-flrahmo-heptulosonic acid 7-phosphate) and methylglyoxal, which then is reduced with either... 

Polyethylene terephthalate is unsuitable for carpets because it crystallizes slowly and the fibers therefore break with time and wear. However, if EG is replaced by 1,3-propanediol, the fibers do not crystallize and wear resistance is greatly improved. The 1,2-diol has properties similar to EG. There are several routes to prepare this diol with reasonable selectivity from propane. 

The superior properties of polypropylene terephthalate) (PPT) polymer and fibers over the chemically analogous poly(ethylene terephthalate) (PET, used for soda bottles) and poly(butylene terephthalate) (PBT) have been well known for several decades PPT fibers are much more elastic and less brittle than PET and offer better recovery from stretching than PBT they are also easier to dye than either PET or PBT. Compared to the intermediate for PET, ethylene glycol, which is available inexpensively from ethylene oxide, and to that for PBT, butanediol, likewise available inexpensively from butene or butadiene, the intermediate for PPT, 1,3 propanediol (1,3-PPD or PDO), was not - and on a large scale is still not - available. Three processes, two chemical ones and one biotechnological, compete to change this situation (Figure 20.10). 

Together with purified terephthalic acid, 1,3-propanediol is used to produce polytrimethylene terephthalate (PTT), a polymer with remarkable "stretch-recovery" properties. The desirable attributes of PTT have been known since the 1940s, but high production costs prevented its entrance into the polymer market (29). In the 1990s, a new fossil-based route to 1,3-propanediol was developed enabling the production of PTT for higher-value applications, and PTT polymers were introduced into the market by DuPont and Shell Chemicals (29,30). 

DuPont expects PTT to stay at the same pricing level as nylon 6, though the company believes that the polymer s properties, and not price, will drive demand (32). Based on its use in PTT, 1,3-propanediol has a potential 2020 market of 230,000 metric t. 

In addition to its use in PTT, 1,3-propanediol can replace traditional glycols in urethane-based polymer systems, improving thermal and hydrolytic stability. As a partial substitute for traditional glycols in polyester systems, 1,3-propanediol can improve coating flexibility without affecting other key properties. Other applications include engine coolants and water-based inks (33). 

One way of improving the physical and mechanical properties of the polymeric materials produced was to copolymerize the original monomers with stiffer comonomers, whose corresponding homopolymers are endowed with high thermal and mechanical properties. Therefore, 1,4-cyclohexanedimetha-nol was copolymerized with 1,3-propanediol and succinic acid. Segmented copolymers between oligofpropylene succinate)s and PEG were also produced in order to modify their hydrophilic/hydrophobic properties. 

Protein-chemical Properties of Apoenzyme. Adenosylcobalamin-dependent diol dehydrase was discovered and isolated first by Abeles and co-workers (3, 4) in the cells of Klebsiella pneumoniae (formerly known as Aerohacter aero genes) ATCC 8724 grown without aeration in a glycerol or glycerol-1,2-propanediol medium. This enzyme catalyzes the conversion of 1,2-propanediol, 1,2-ethanediol, and glycerol to propionaldehyde, acetaldehyde, and j3-hydroxypropionaldehyde, respectively (4, 5). Adenosylcobalamin and K+ or other monovalent cations of a similar size are required for catalysis. Recently, the au-... 

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