Linked Life Data

11257295

Source:http://linkedlifedata.com/resource/pubmed/id/11257295

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-3-21
pubmed:abstractText
An optimal dental restorative polymeric material would have a homogeneous cross-linking density giving it consistent mechanical strength throughout the material. When multifunctional monomers are polymerized, a pendant double bond can react intramolecularly with the radical on its propagating chain to form a loop, which results in a primary cyclization reaction. Primary cyclization does not contribute to overall network structure, causes microgel formation, and leads to heterogeneity in the polymer. Knowledge of how cure conditions control the degree of primary cyclization and cross-linking in the polymer is important in developing better dental materials. To gain more understanding about the evolving polymer network, the photopolymerization of a typical dental resin (75/25 wt% bis-GMA/TEGDMA) is modeled using a first principals approach. The overall polymerization rate behavior of 75/25 wt% bis-GMA/TEGDMA is predicted using experimentally obtained propagation and termination kinetic rate constants. The effect of chain stiffness and light intensity on the polymerization kinetics is also explored. Furthermore, the model predicts the extent of cross-linking and primary cyclization in the growing polymer network. At 45% conversion, the fraction of bis-GMA and TEGDMA pendant double bonds created that have cycled is 11 and 33%, respectively. The model shows that using a stiff monomer, like bis-GMA, in dental resins diminishes the extent of cyclization and increases the cross-linking density of the polymer. Therefore, better mechanical properties are obtained than if more flexible monomers were used.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
D
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0109-5641
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
221-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:11257295-Algorithms, pubmed-meshheading:11257295-Binding Sites, pubmed-meshheading:11257295-Bisphenol A-Glycidyl Methacrylate, pubmed-meshheading:11257295-Chemistry, Physical, pubmed-meshheading:11257295-Composite Resins, pubmed-meshheading:11257295-Dental Materials, pubmed-meshheading:11257295-Dental Restoration, Permanent, pubmed-meshheading:11257295-Elasticity, pubmed-meshheading:11257295-Humans, pubmed-meshheading:11257295-Kinetics, pubmed-meshheading:11257295-Light, pubmed-meshheading:11257295-Models, Chemical, pubmed-meshheading:11257295-Molecular Structure, pubmed-meshheading:11257295-Physicochemical Phenomena, pubmed-meshheading:11257295-Pliability, pubmed-meshheading:11257295-Polyethylene Glycols, pubmed-meshheading:11257295-Polymers, pubmed-meshheading:11257295-Polymethacrylic Acids, pubmed-meshheading:11257295-Stress, Mechanical, pubmed-meshheading:11257295-Surface Properties
pubmed:year
2001
pubmed:articleTitle
Primary cyclization in the polymerization of bis-GMA and TEGDMA: a modeling approach to understanding the cure of dental resins.
pubmed:affiliation
Department of Chemical Engineering, University of Colorado, Boulder, 80309-0424, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't