Volume polymerization

Methacrylate polymerizations are accompanied by the Hberation of a considerable amount of heat and a substantial decrease in volume. Both of these factors strongly influence most manufacturing processes. Excess heat must be dissipated to avoid uncontrolled exothermic polymerizations. Volume changes are particularly important in sheet-casting processes where the mold must compensate for the decreased volume. In general, the percent shrinkage decreases as the size of the alcohol substituent increases on a molar basis, the shrinkage is relatively constant (35). 

Polymer resins were first introduced in the early 1940s as an aesthetic alternative to repair defects in anterior teeth. Some of the first resins were unfilled polymers of methyl methacrylate. Presently, these unfilled resins have been replaced by filled composite materials that limit the problems associated with polymerization volume shrinkage, abrasion or wear resistance, mechanical properties, water sorption, solubility, and thermal expansion. Polymeric composite materials generally consist of a monomer resin, a ceramic filler, a polymerization initiator or initiating system, and a coupling agent which binds the polymer... 

S. Kobayashi, T. Saegusa, Ring-opening Polymerization Volume 2, Elsevier Applied Science Publishers, London, New York, 1984, p. 761. 

Relmschuessel, H.K., In "Kinetics and Mechanisms of Polymerization, Volume 2, Ring Opening Polymerization" Frisch, K.C. Reegen, S.L., Eds. Marcel Dekker New York, 1969 Chapter 7. 

The presence of crystallites, which are assumed to be impermeable, makes a fraction of the polymeric volume unavailable for transport. 

Sampie Molecular weight (Mw x 10-4) Degree of polymerization Volume fraction Kas/Ku K33/K22 to to... 

FontaniUe M. Carbanionic polymerization termination and functionalization. In Eastmond GC, Ledwith A, Russo S, Sigwalt P, editors. Comprehensive Polymer Science. Chain polymerization. Volume 3. Ebnsford (NY) Pergamon Press 1989. p 425, Part I, Chapter 27. 

Ivin KJ, Saegusa T. Ring-Opening Polymerization. Volume I 11. London Elsevier 1984. 

Chain polymerization of vinyl monomer dispersed in form of large drops in aqueous medimn. The polymerization is initiated by monomer-soluble initiator thus, each drop can be treated as individual bulk polymerizing volume. 

P. Sigwalt and N. Spassky, in "Ring-Opening Polymerization," Volume 2,... 

Guyot A, GuUlot J, Pichot C, Rios Guerrero L. New design for producing constant-composition copolymers in emulsion polymerization. In Basset DR, Hamielec AE, editors. Emulsion Polymers and Emulsion Polymerization, Volume 165. ACS Symposium Series. Washington, DC American Chemical Society 1981. pp 415-436. 

Figure 5 Phase diagram of diblock copolymers with equal segmental lengths and segmental volumes of both block components. % Flory-Huggins-Staverman interaction parameter, N degree of polymerization, ( ) volume fraction, D disordered phase, CPS close packed spheres, BCC body-centered cubic spheres, H hexagonally packed cylinders, G gyroid, L lamellae. (From Ref. 110, Copyright 1996 American Chemical Society.)...

Allen, G. and J. C. Bevington (eds.), Comprehensive Polymer Science , Pergamon Press, Oxford, 1989. A series of volumes that show the relationship between methods of preparation, treatment, structure and properties. It is organized into seven volumes Volume 1, Polymer Characterization Volume 2, Polymer Properties Volumes 3 and 4, Chain Polymerization Volume 5, Step Polymerization Volume 6, Polymer Reactions Volume 7, Specialty Polymers and Polymer Processing. A cumulative subject index completes the final volume. 

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