scholarly journals Residual Monomer Content Affects the Interpretation of Plastic Degradation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Franziska Klaeger ◽  
Alexander S. Tagg ◽  
Stefan Otto ◽  
Matthias Bienmüller ◽  
Ingo Sartorius ◽  
...  
Keyword(s):  
Residual Monomer ◽  
Monomer Content ◽  
Plastic Degradation

scholarly journals A GAS CHROMATOGRAPHY STUDY ON THE EFFECT OF TWO DIFFERENT CURING CYCLES ON THE RESIDUAL MONOMER CONTENT OF TWO DIFFERENT HEAT CURE DENTURE BASE RESINS.

2020 ◽  
pp. 4-6
Author(s):  
Joy PT ◽  
Bennett Atlin Correya ◽  
V. K Zahida ◽  
Gilsa K. Vasunni ◽  
Julie George Alapatt
Keyword(s):  
Mechanical Properties ◽  
Gas Chromatography ◽  
Allergic Reactions ◽  
Residual Monomer ◽  
Chromatography Method ◽  
Denture Base ◽  
Heat Cure ◽  
Monomer Content ◽  
Methacrylate Monomer ◽  
Methyl Methacrylate Monomer

The conversion of monomer to polymer is not complete in denture base resins and residual monomer left can cause mucosal irritation, inflammation, and allergic reactions in tissues adjacent to dentures. The mechanical properties of denture base resins have been found to be lacking with increased residual monomer content. Therefore, it is desirable to reduce the residual monomer content in the processed denture. In the present study Gas chromatography method was used to determine the levels of residual methyl methacrylate monomer of two different brands of heat cure denture base resins processed by two different polymerization cycles. The study concluded that while processing the denture sufficient length of boiling phase should be given and for each brand, manufacturer’s instructions should be strictly followed while selecting polymerization cycle.

Variation of residual monomer content of poly(methyl methacrylate) dental resins with time, and the influence of water immersion

1989 ◽  
Vol 4 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Robin M. Basker ◽  
Jill Collier ◽  
Ian Smith ◽  
Keith D. Bartle ◽  
Bernard Frere ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Water Immersion ◽  
Residual Monomer ◽  
Poly Methyl Methacrylate ◽  
Dental Resins ◽  
Influence Of Water ◽  
Monomer Content

Minimization of residual monomer content of superabsorbent hydrogels via alteration of initiating system

2011 ◽  
Vol 120 (5) ◽  
pp. 2716-2723 ◽  
Author(s):  
K. Kabiri ◽  
S. Hesarian ◽  
A. Jamshidi ◽  
M. J. Zohuriaan-Mehr ◽  
H. Boohendi ◽  
...  
Keyword(s):  
Residual Monomer ◽  
Monomer Content ◽  
Superabsorbent Hydrogels

scholarly journals Effects of Monomer Composition of Urethane Methacrylate Based Resins on the C=C Degree of Conversion, Residual Monomer Content and Mechanical Properties

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4415
Author(s):  
Codruta Sarosi ◽  
Marioara Moldovan ◽  
Andrada Soanca ◽  
Alexandra Roman ◽  
Timea Gherman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Degree Of Conversion ◽  
Chain Growth ◽  
Structure Property ◽  
Residual Monomer ◽  
Radical Chain ◽  
Dental Resins ◽  
Monomer Content

(1) Background: This study investigated the influence of Bis-GMA, TEGDMA, UDMA, and two different polyethylene glycol (PEG)-containing, UDMO-based co-monomers on the Young’s modulus and flexural strength, degree of methacrylate C=C double bond conversion and residual monomer elution of experimental dental resins. (2) Methods: Urethane methacrylate-based monomer was synthesised via a radical chain growth polymerization mechanism using PEG in order to improve the mechanical properties. Dental resins were formulated using Bis-GMA, UDMA, or UDMO as base monomers combined with TEGDMA as a dilution monomer and DMAEM + CQ as the photo-initiator system. Degree of conversion (DC), mechanical properties, and residual monomer content of light-activated methacrylate resin formulations were evaluated and statistically analysed by ANOVA and a Tukey’s test. (3) Results: PEG-containing UDMO resins had lower Young’s modulus and elastic strength than UDMA-derived resin for all irradiation times. The highest DC (67,418%) was observed for the PEG-containing UDMO-based resin formulation when light cured for 40 s. For all samples, DC increased with the photo-polymerization time. The amount of residual monomer decreased after increasing the light-curing period from 20 to 40 s, resin with UDMO content 0.01 mol of PEG having the smallest amount of free eluted monomer. (4) Conclusions: A strong structure–property relationship exists in photo-cured dimethacrylate-based dental resins. The time and quantity of the photochemical initiation system can influence the physical–mechanical properties of the resins but also the monomers in their composition.

scholarly journals Acrylic Bone Cement Incorporated with Low Chitosan Loadings

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1617 ◽  
Author(s):  
Mayra Eliana Valencia Zapata ◽  
José Herminsul Mina Hernandez ◽  
Carlos David Grande Tovar
Keyword(s):  
Bone Cement ◽  
Weight Bearing ◽  
Setting Time ◽  
Acrylic Bone Cement ◽  
Residual Monomer ◽  
Water Contact ◽  
Bending Modulus ◽  
Wide Range ◽  
Monomer Content

Despite the potential of acrylic bone cement (ABC) loaded with chitosan (CS) for orthopedic applications, there are only a few in vitro studies of this composite with CS loading ≤ 15 wt.% evaluated in bioactivity tests in simulated body fluid (SBF) for duration > 30 days. The purpose of the present work was to address this shortcoming of the literature. In addition to bioactivity, a wide range of cement properties were determined for composites with CS loading ranging from 0 to 20 wt.%. These properties included maximum exotherm temperature (Tmax), setting time (tset), water contact angle, residual monomer content, flexural strength, bending modulus, glass transition temperature, and water uptake. For cement with CS loading ≥ 15 wt.%, there was an increase in bioactivity, increase in biocompatibility, decrease in Tmax, increase in tset, all of which are desirable trends, but increase in residual monomer content and decrease in each of the mechanical properties, with each of these trends, were undesirable. Thus, a composite with CS loading of 15 wt.% should be further characterized to explore its suitability for use in low-weight-bearing applications, such as bone void filler and balloon kyphoplasty.

Techniques for reducing residual monomer content in polymers: A review

2002 ◽  
Vol 42 (7) ◽  
pp. 1442-1468 ◽  
Author(s):  
P. H. H. Araújo ◽  
C. Sayer ◽  
R. Giudici ◽  
J. G. R. Poço
Keyword(s):  
Residual Monomer ◽  
Monomer Content

Characterization of Aerosol Release during Spraying of Isocyanate Products

2019 ◽  
Vol 63 (7) ◽  
pp. 773-783
Author(s):  
Colin Ehnes ◽  
Manfred Genz ◽  
Jörn Duwenhorst ◽  
Jurij Krasnow ◽  
Jan Bleeke ◽  
...  
Keyword(s):  
Size Fraction ◽  
Spray Coating ◽  
Reaction Products ◽  
Residual Monomer ◽  
Particle Size Fractions ◽  
Aerosol Mass ◽  
Two Component ◽  
Mass Release ◽  
Monomer Content

Abstract The aerosol release during the professional application of two different isocyanate based two component spray systems was identified and the physicochemical properties of the released airborne aerosols were characterized. For this purpose, aerosol release fractions were measured using a mass balance method described by Schwarz and Koch. Besides the release of total aerosol mass special emphasis was directed to the content of free monomeric MDI (4,4′- and 2,4′-diphenylmethane diisocyanate) in three particle size fractions relevant for inhalation uptake: inhalable, thoracic, and respirable size fraction. Two products were investigated: a two component PUR (polyurethane) spray foam (Elastopor) and a polyurea spray coating (Elastocoat). The mass fraction of the applied products released with the overspray as inhalable aerosol is 6.3 × 10−4 (Elastopor) and 4.0 × 10−4 (Elastocoat). Of the released total overspray aerosol 75 or 80% were in the thoracic size range, and 26 or 47% in the respirable regime for the PUR spray foam or the polyurea spray coating, respectively. At the time point of release the content of monomeric MDI in the aerosol corresponds to the composition of the bulk product. However, analysis of air samples indicates that <1% of the spray foam aerosol mass release fraction is attributed to free monomeric 4,4′- and 2,4′-MDI. For the Spray Coating the monomeric MDI fraction is <0.1%. Higher oligomers of MDI and prereacted oligomeric reaction products make up a few percent of the aerosol. This results in a total fraction of 0.0023% (spray foam) and 0.00015% (spray coating), respectively, of the sprayed monomeric MDI that is transferred into an inhalable aged aerosol. This data demonstrates, that during professional spraying only a small fraction of the total applied mass is released as airborne aerosol. The potential distribution of the theoretically inhalable aerosol in the respiratory tract and a low residual monomer content is described, significantly contributing to a refined safety assessment of the spray applications at the workplaces.

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