Propylene oxide toluene diisocyanate

Da Roz et al. synthesized and characterized new starch cross-linked PUs produced by the reaction of native corn starch with a propylene oxide toluene diisocyanate oligomer (PTD) [126]. They studied the thermogravimetric behavior of the unmodified native starch, the cross-linked starches and the PTD by TGA (Figure 7.4). 

No by-product is formed from this reaction. Toluene diisocyanate (Chapter 10) is a widely used monomer. Diols and triols produced from the reaction of glycerol and ethylene oxide or propylene oxide are suitable for producing polyurethanes. 

Dragunski, D. C. and PawHcka A. (2001). Preparation and characterization of starch Grafted with Toluene Poly (propylene oxide) diisocyanate. Mater. Res., 4, 77-81. 

One way of obtaining the more useful cross-linked polyurethanes is by using a trifunctional reagent. Thus either the toluene diisocyanate can react with a triol or the propylene oxide can be polymerized in the presence of a triol. 

Polyurethane is also used as a foam, mostly in sheet form as an underlay or middle layer for example in fruit bins. The following starting materials for polyurethane foam can be used polyester with hydroxyl end groups made from adipic acid, diethylene glycol, trimethylol propane as well as polyether based on ethylene oxide and/or propylene oxide with free hydroxyl groups in combination with 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. Stabilizers, dispersants and amines (as catalysts in amounts up to 1.2 %) can be used. 

The value of a for poly(propylene oxide) was obtained from the data of Moacanin 189) for polyurethanes prepared by condensation of toluene-2,4-diisocyanate with atactic polypropylene glycols of molecular weights about 1000 and 2000. The small quantity of diisocyanate present in these compositions can make only a negligible effect on the chain dimensions (less than one per cent on the freely rotating chain, as is... 

No further features of the mechanism of this catalysis were given. When toluene diisocyanate is employed with propylene oxide and pyridine, a highly cross-linked resin is obtained. 

Polyurethane (PU) PV membranes were reported by Schauer et al. (1999). PU membranes were prepared by the reaction of toluene-2,4-diisocyanate with hydroxyl-terminated oligomers. Oligomers were either liquid polybutadiene (PB) (MW 3000) or propylene oxide-based PEs (MW 420 and 4800). The prepared membranes were used in PV of binary mixtures of water-EtOH, water-dioxane, and EtOH-toluene, respectively. Membranes obtained from the polymer quatemized poly[3-(N, N -dimethyl)aminopropylamide-co-acrylonitriles] showed selective separation of water from aqueous EtOH solution by PV (Yoshikawa et al. 1991). The separation factor toward water reached over 15,000. Membrane performance showed a good correlation to membrane polarity. DSC melting endotherms of the water-swoUen membranes were studied to clarify the state of water in the membrane. The resnlts suggested that there were two states of water in the membrane bound and free. The higher the fraction of bound water in the membrane, clearly, the more preferentially was water permeated. 

Figure 2.3. Chemical structures of hard and soft segments. Each hard segment contains isocyanate and chain extender. Isocyanates 4,4-inethyleiie diisocyanate (MDI) and toluene diisocyaiiate (TDI). Chain extenders water (for TDI-PU), 3,5-diethyltoluenediamine (for MDI-DETDA), and 1,4-butanediol (for MDI-BDO). Soft segments poly(propylene oxide) (PO) [33]...

DMSO using persulfate as the initiator. Chen et al. studied FP of poly(propylene oxide) glycol, 2,4-toluene diisocyanate, and 1,4-butanediol with the catalyst stannous caprylate in dimethylbenzene. At room temperature, bulk polymerization did not occur quickly, and the pot life could be extended to 6 h if the solution was cooled to 10 °C. Mariani et al prepared diurethane diacrylates. 

Starch Toluene poly(propylene oxide) diisocyanate UCIO4 3.5 X 10" 40... 

Ammonia is used in the fibers and plastic industry as the source of nitrogen for the production of caprolactam, the monomer for nylon 6. Oxidation of propylene with ammonia gives acrylonitrile (qv), used for the manufacture of acryhc fibers, resins, and elastomers. Hexamethylenetetramine (HMTA), produced from ammonia and formaldehyde, is used in the manufacture of phenolic thermosetting resins (see Phenolic RESINS). Toluene 2,4-diisocyanate (TDI), employed in the production of polyurethane foam, indirectiy consumes ammonia because nitric acid is a raw material in the TDI manufacturing process (see Amines Isocyanates). Urea, which is produced from ammonia, is used in the manufacture of urea—formaldehyde synthetic resins (see Amino resins). Melamine is produced by polymerization of dicyanodiamine and high pressure, high temperature pyrolysis of urea, both in the presence of ammonia (see Cyanamides). 

---