Monomer Effects

Radiation-Induced Cross-Linking in the Presence of CTFE/Butadiene Mixture. On the basis of the results mentioned in the previous section, it is concluded that in the irradiation of polyethylenes in the presence of CTFE the polyethylenes are mainly cross-linked through the addition reaction of the unsaturated groups contained in the main and the side chains of the polymers to the propagating graft chain radical of CTFE. Therefore, the radiation-induced cross-linking of polyethylene is expected to be accelerated by the presence of the mixture of CTFE and a diene monomer effectively than the presence of pure CTFE. 

Fig. 9a-c. Polymerization of acrylic acid by vibromilling polyethylene terephthalate a) effect of milling time at 18° C on acid number of interpolymers b) effect of temperature after 3 h milling on interpolymer acid number c) monomer effect on interpolymer add number... 

Table 12. Polymerization of styrene by poly(methyl acrylate) mastication (30% of monomer). Effect of rubber molecular weight on interpolymer composition (/i)...

To summarize, macromonomers in polymerization and copolymerization are only fairly well understood compared to the conventional monomers. Effects, such as conformational, morphological, or due to incompatibility caused by the macromonomer chains, remain to be further investigated. As a result, the macromonomer technique is expected to lead to other unique applications including construction of novel branched architectures. 

A number of antioxidants were examined for solubility in the monomer, effect upon the photoinitiator, UV stability, effect upon physical properties of the cured coating and their effectiveness as stabilizers. The addition of hydrogen donors, HD-2 or HD-3, or a hindered amine light stabilizer, HALS-1, improves the stability of a cured epoxy acrylate system with a minimal change in the physical properties of the resin. DSC and oxygen absorption measurements show that the secondary hindered amine, HALS-1, imparts the best stability to the resin. 

Another method of achieving the desired molecular weight is by addition of a small amount of a monofunctional monomer. The monofunctional monomer effectively caps the chain end it reacts with and prevents further growth of the chain. 

Y. Ishida, A. C. F. Sun, M. Jikei and M. Kakimoto, Synthesis of hyperbranched aromatic polyamides starting from dendrons as monomers Effect of monomer multiplicity on the degree of branching , Macromolecules, 2000, 33, 2832-8. 

WAR Ward, M.A. and Georgiou, T.K., Thermoresponsive terpolymers based on methacrylate monomers Effect of architecture and composition, J. Polym. ScL Part A Polym. Chem., 48, 775, 2010. 

The assignment was confirmed by examination of poly (vinyl fluoride) free from inverted units. This material was made by reductive dechlorination of poly(l-fluoro-l-chloroethylene) by means of tri-n-butyltin hydride the bulky chlorine atom in the monomer effectively prevents head-to-head growth. The F spectrum of poly (vinyl fluoride) prepared by this indirect route contained only the signals in the range 178-185 ppm. 

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