Frontal Polymerization with Thiol−Ene Systems

Pojman, John A.; Varisli, Birsen; Perryman, A.C.; Edwards, C. O.; Hoyle, Charles E.

doi:10.1021/ma035751a

Cited by 91 publications

(90 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2,3 As a result of these benefits, thiol−ene polymerization schemes are being used in various applications such as functionalization of nanoparticles, 4−7 surface modification, 8,9 and fabrication of biomaterials. 10 Despite the strong interest, most thiol−ene systems currently investigated are produced via frontal polymerization 11,12 or photoinitiation, 13−15 which requires increased temperature or an external light source and photoinitiator, respectively. Additionally, these reactions produce radicals that may remain in the final product and leach into the body when used in biomedical applications.…”

Section: ■ Introductionmentioning

confidence: 99%

Gelation and Cross-Linking in Multifunctional Thiol and Multifunctional Acrylate Systems Involving an in Situ Comonomer Catalyst

et al. 2014

Self Cite

View full text Add to dashboard Cite

Dynamic rheology in combination with Fourier transform infrared spectroscopy (FTIR) is used to examine the gelation kinetics, mechanism, and gel point of novel thiol−acrylate systems containing varying concentrations of an in situ catalyst. Gelation, as evidenced from the gel time determined using the Winter− Chambon criterion, is found to occur more quickly with increasing catalyst concentration up until a critical catalyst concentration of 22 mol %, whereupon the gel time lengthens. Such a minimum in gel time may be attributed to changes in the number of available reaction sites and percentage conversion required for gelation. Chemical conversions at the gel point measured for representative samples are consistent with theoretical values calculated using Flory−Stockmayer's statistical approach, confirming our hypothesis. Relaxation exponents of 0.97 and fractal dimensions of 1.3 are calculated for all samples, consistent with coarse-grained discontinuous molecular dynamics (DMD) simulations. The elevated value of n may be due to the low molecular weight prepolymer. The relaxation exponent and fractal dimensions are invariable over all systems studied, suggesting the cross-linking mechanism remains unaffected by changes in catalyst concentration, allowing the gel time to be tailored by simply modulating the catalyst concentration.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Gelation and Cross-Linking in Multifunctional Thiol and Multifunctional Acrylate Systems Involving an in Situ Comonomer Catalyst

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…Ratios of 1:1 and 4:3 by weight of acrylate to thiol did not frontally polymerize due to the high concentration of thiol. 18 …”

Section: Discussionmentioning

confidence: 99%

In vitro evaluation of thermal frontally polymerized thiol‐ene composites as bone augments

et al. 2015

Self Cite

View full text Add to dashboard Cite

Because of the large number of total knee replacement (TKR) surgeries conducted per year, and with projections of increased demand to almost a million primary TKR surgeries per year by 2030 in the United States alone, there is a need to discover more efficient working materials as alternatives to current bone cements. There is a need for surgeons and hospitals to become more efficient and better control over the operative environment. One area of inefficiency is the cement steps during TKR. Currently the surgeon has very little control over cement polymerization. This leads to an increase in time, waste, and procedural inefficiencies. There is a clear need to create an extended working time, moldable, osteoconductive, and osteoinductive bone augment as a substitution for the current clinically used bone cement where the surgeon has better control over the polymerization process. This study explored several compositions of pentaerythritol-co-trimethylolpropane tris-(3-mercaptopropionate) hydroxyapatite composite materials prepared via benzoyl peroxide-initiated thermal frontal polymerization. The 4:1 acrylate to thiol ratio containing augment material shows promise with a maximal propagation temperature of 160°C ± 10°C, with mechanical strength of 3.65 MPa, and 111% cytocompatibility, relative to the positive control. This frontally polymerized material may have application as an augment with controlled polymerization supporting cemented implants.

show abstract

“…12 It has been demonstrated that various components of these systems can be microencapsulated, including monomers, 13 initiators, 12,14 and catalysts. 15 This method of polymerization has been demonstrated with several different mechanisms of reaction, including free-radical polymerization, 12,14-17 anionic polymerization, 18 ring-opening polymerization, 19 step-growth polymerizations, 20,21 thiol-ene polymerizations, 22 and curing of epoxides. 15 This method of polymerization has been demonstrated with several different mechanisms of reaction, including free-radical polymerization, 12,14-17 anionic polymerization, 18 ring-opening polymerization, 19 step-growth polymerizations, 20,21 thiol-ene polymerizations, 22 and curing of epoxides.…”

Section: Introductionmentioning

confidence: 99%

Effects of shell crosslinking on polyurea microcapsules containing a free‐radical initiator

McFarland

2015

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

Microencapsulation of a material is often used when a controlled release of a substance is desired. This study examines the effects of crosslinking in polyurea microcapsule shells on stability of microcapsules containing the free-radical initiator cumene hydroperoxide (CHP). Crosslinking of polyurea shells was varied by using amine monomers containing different amine functionalities, and/or changing the isocyanate/primary amine ratio. Thermogravimetric analysis was performed to determine thermal properties of these microcapsules, and the pot lives of monomer systems containing these microcapsules were measured. Thermal stability is greater with a moderate degree of crosslinking from a trifunctional amine, and decreases when crosslinking is increased through use of higher amine functionality. Stability in monomer media generally increases with increased crosslinking through higher amine functionality, but is less predictable due to crosslinks formed between capsules. Generally, increasing crosslinking through altering the isocyanate to primary amine ratio decreases capsule stability in both dry and monomer storage.

show abstract

Frontal Polymerization with Thiol−Ene Systems

Cited by 91 publications

References 30 publications

Gelation and Cross-Linking in Multifunctional Thiol and Multifunctional Acrylate Systems Involving an in Situ Comonomer Catalyst

Gelation and Cross-Linking in Multifunctional Thiol and Multifunctional Acrylate Systems Involving an in Situ Comonomer Catalyst

In vitro evaluation of thermal frontally polymerized thiol‐ene composites as bone augments

Effects of shell crosslinking on polyurea microcapsules containing a free‐radical initiator

Contact Info

Product

Resources

About