Effects of hyperbranched polyesters on kinetics of the reaction between hydroxyl-terminated polybutadiene (HTPB) and isophorone diisocyanate (IPDI) were investigated. HTPB and IPDI were in-situ cured in the presence of two different hyperbranched polyesters, stearic acid ester-terminated hyperbranched polyester (SHPE) and acetate-terminated hyperbranched polyester (AHPE). The curing processes w...

8.1 CHAPTER SUMMARY Segmented polyurethane and polyurea copolymers whose hard segments are based on only a single diisocyanate molecule are thermoplastic; they can exhibit useful structural properties if the level of symmetry and/or cohesiveness of the hard microdomains is carefully selected. These parameters control the hard segments’ ability to establish long-range connectivity and percolatio...

The primary use of methyl isocyanate (MIC, CAS no. 624-83-9) is as a chemical intermediate in the production of carbamate pesticides. MIC is also used to produce polyurethane foam and plastics (ATSDR, 2002). Isocyanic acid (ICA, Cas no. 75-138) does not have commercial uses because of its instability. The potential for occupational exposure to ICA largely arises when it is generated as a therma...

In the strict sense of chemical terminology, MDI is the acronym for the monomer methylene diphenyl diisocyanate. However, the term “MDI” is also often applied to the common commercial product, which is more properly termed polymeric MDI or PMDI. Polymeric MDI, also known as “crude MDI” is actually a mixture that contains 45 55 percent MDI (monomer), with the balance being “oligomers” (polymer i...

Toluene diisocyanate was conjugated by two different methods to human serum albumin. These conjugates were used as antigens in the radio-allergo-sorbent-test (RAST) for detection of IgE antibodies in sera of isocyanate-sensitized persons. Chemical analyses have shown that conjugates containing 18-28 mol of isocyanate residues per mol protein were more potent antigens than those containing great...

Reported cases of allergic contact dermatitis caused by methylenediphenyl diisocyanate (MDI) have increased and thereby increased the need for adequate skin protection. Current standardized permeation and penetration test methods give information about efficacy of protective materials against individual components of the polyurethane systems. They do not give information of what kind of clothin...

Ultraviolet and heat-curable polyurethane acrylate prepolymers were synthesized from 4,4’-diphenyl methane diisocyanate, polyethylene adipate diol, polyhexamethylene carbonate diol, polycaprolactone diol and 1,6hexamethylene diamine , acrylic acid. Effects of nature of the soft segments on the physical properties were investigated. It was found that the thermal stability increased from polycarb...