Formaldehyde graft with

TABLE iv. REACTION OF PAM GRAFT WITH FORMALDEHYDE AND AMINES... 

Ionic grafting of oligoolefins is less frequently employed. Thus, a solution in n-hexane of oligopropylene (2 to 10% concentration) is saturated by barbotage at 40°C with anhydrous formaldehyde. Formaldehyde grafting is initiated with tri-butylamine. The process lasts 3 h at 40°C [989]. 

A waterborne system for container coatings was developed based on a graft copolymerization of an advanced epoxy resin and an acryHc (52). The acryhc-vinyl monomers are grafted onto preformed epoxy resins in the presence of a free-radical initiator grafting occurs mainly at the methylene group of the aHphatic backbone on the epoxy resin. The polymeric product is a mixture of methacrylic acid—styrene copolymer, soHd epoxy resin, and graft copolymer of the unsaturated monomers onto the epoxy resin backbone. It is dispersible in water upon neutralization with an amine before cure with an amino—formaldehyde resin. 

Amine-modified polyamides can be prepared by condensation with formaldehyde and aromatic amines at room temperature the pendant groups are reported to act as active centers for grafting of acrylonitrile, acrylamide, methyl methacrylate and N-vinyl pyrrolidone (152). 

Kamogawa, and Sekiya (54) studied the graft polymerization of acrylamide onto cotton fabric using ceric ammonium nitrate as the catalyst. Similarly to Kulkarni et al. (35) the authors performed subsequent cross-linking with formaldehyde amd methylol compounds. From precipitation studies by acidification of cuprammonium solutions on mixtures of polyacrylamide and cellulose on the one hand and polyacrylamide-cellulose grafts on the other the authors conclude that chemical bonds must exist between the two polymers in the grafted product. 

The mechanical degradation and production of macroradicals can also be performed by mastication of polymers brought into a rubbery state by admixture with monomer several monomer-polymer systems were examined (10, 11). This technique was for instance studied for the cold mastication of natural rubber or butadiene copolymers in the presence of a vinyl monomer (13, 31, 52). The polymerization of methyl methacrylate or styrene during the mastication of natural rubber has yielded copolymers which remain soluble up to complete polymerization vinyl acetate, which could not produce graft copolymers by the chain transfer technique, failed also in this mastication procedure. Block and graft copolymers were also prepared by cross-addition of the macroradicals generated by the cold milling and mastication of mixtures of various elastomers and polymers, such as natural rubber/polymethyl methacrylate (74), natural rubber/butadiene-styrene rubbers (76) and even phenol-formaldehyde resin/nitrile rubber (125). 

The initial research objectives included developing a simple experimental procedure to study how the graft polymers, polystyrene, and a commercial phenol formaldehyde resin interact when combined with wood under heat and pressure. Two-ply lap shear test specimens were used for a comparative test. 

Kulkami et al.94 subjected cotton-PAN graft copolymer to alkaline hydrolysis, methylolated the resulting product at pH 9.5-10 with formaldehyde for 24 h and cross-linked the polymer in an acidic medium at 150°C in the presence of MgC for 5 min. This treatment increased the wrinkling resistance of the cotton fabric appreciably. No effect, however, was observed if the grafted chains were cross-linked by 1,4-divinylbenzene simultaneously with grafting. 

The calculations of potential energy surface profiles done in Ref. [85] showed as well that the main route of decomposition is consistent with the evolution of formaldehyde and upon a further temperature increase - with that of CO and H2. However, it is not ruled out that at high temperatures of the grafted organic group destruction there are both heterolytic and homolytic processes. 

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