Modified diphenylmethane

Fig. 15. Viscoelastic behavior of isocyanurate-oxazoiidone resins51). DEN 431 (polyglycidyl ether of phenol-formaldehyde novolac Dow Chemical Co.), EP 4080 (2,2-bis[p-(2,3-epoxypropyloxy)cyclo-hexane]propane Asahi Denka, Ltd.), EP 871 (diglycidyl ester of linoleic dimer acid Shell Chemical Co.), and L-MDI (modified diphenylmethane-4,4 -diisocyanate Desmodur CD Bater AG)...

To address this concern uretonimine-modified isocyanates with improved low-temperature properties were prepared using 4,4 -diphenylmethane diisocyanate catalyzed with 3-methyl-l-phenyl-3-phospholene-l-oxide. The formation of uretonimine was consistently higher than uretdione formation using this catalyst. The uretonimine-modified isocyanate can be stored at temperatures substantially lower than ambient temperature while still remaining liquid. In addition it is soluble in melted 4,4 -diphenylmethane diisocyanate. 

TABLE 1. Scoping Reactions for Preparation of Urctonimine-Modified Isocyanate Using 93.80% 4,4 -Diphenylmethane Diisocyanate Containing 6.20% 2,4 -Diphenylmethane Diisocyanate Conducted at 105-108°C Using 3-Methyl-l-phenyl-3-phosphoIene-l-oxide as Catalyst... 

Basic paper, polyacrylonitrile, modified nylon, polyester and inks applied from acidic dyebaths cyanine, hemicyanine, diazahemi-cyanine, diphenylmethane, triaryl-methane, azo, azine, xanthene, acridine, oxazine, and anthraquinone... 

The polyisocyanates which can be used for preparing isocyanate-based foams are mainly aromatic compounds and some aliphatic or aralkyl polyisocyanates. TDI (toluene diisocyanate) is widely used for flexible foams. Pure MDI (diphenylmethane diisocyanate) is used for elastomers and coatings. Modified TDI and modified MDI are used for high-resilience flexible foams. Polymeric isocyanates (polymeric MDI or oligomeric MDI) are mostly used for preparing rigid urethane and isocyanurate foams, and in part, for preparing flexible and semi-flexible foams. 

Fig. 1.5 Schematic representation of shape selective effects a) Reactant selectivity Cracking of an n-iso C6 mixture, b) Product selectivity Disproportionation of toluene into para-xylene over a modified HFMI zeolite, c) Spatioselectivity Disproportionation of meta-xylene over HMOR. The diphenylmethane intermediate A in formation of 1,3,5 trimethylbenzene is too bulky to be accommodated in the pores, which is not the case for B...

Fig. 21 Comparison of fracture surfaces of (a) neat diethyltoluene diamine cured tetraglycedyl diamino diphenylmethane resin system (top) and (b) its corresponding nanocomposite containing 7.5% octadecyl ammoninm modified layered silicate...

To the tannin/hexamine solution were added the modified GA, GB and GC lignin solutions. The proportion of tannin modified lignin was 50 50 by weight as shown in Table 1. The pMDI (polymeric 4,4 -diphenylmethane diisocyanate) used was Desmodur 44VK from Bayer. The PF resin used in one of the formulations in Table 1 was prepared according to the procedure already presented [20]. 

Another polyisocyanate used commercially is diphenylmethane-4,4 -di-isocyanate (MDI) and also finds application here. The epoxy and blocked isocyanate are mixed together and the tertiary amino groups of the modified epoxy resin are partially neutralized with acetic acid before the blend is emulsified in water. 

PUs are formed as a result of a condensation or an adduction reaction between isocyanates and polyols [polyesters or polyethers with terminal hydroxyl (OH) groups, castor oil or tall oil]. If both components are more than difunctional, thermosetting end products are produced. Many auxiliary substances are also used in the manufacture of PU products. The hardening process can be modified by heat or with a catalyst [diamino diphenylmethane or meth-ylenedianiline (MDA), triethylenediamine, triethyl-amine, cobalt naphthenate or nickel salts]. Figure 1... 

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