Mechanism of the Stabilization of Flexible Polyether Polyurethane Foams by Silicone-Based Surfactants

Rossmy, G.; Kollmeier, H.J.; Lidy, W.; Schator, H.; Wiemann, Michael C.

doi:10.1177/0021955x8101700602

Cited by 54 publications

(35 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Decreasing the isocyanate index resulted in more open-cell structures with slightly higher cell sizes, at the expense of greater irregularities, as shown in Fig. 14. This result was in agreement with the well-known behaviour of flexible polyurethane foams (Rossmy et al 1981).…”

Section: Sem Characterization Of Arundo Donax L Hydrolysis Residue Bsupporting

confidence: 92%

“…By increasing the amount of the liquefaction solvents, an increase in size and number of open-cells was observed. Furthermore, opening cell process strictly influences the formation of ureic aggregates (Rossmy et al 1981). However, in this case, only a small amount of the intercellular membranes of the polyurethane foams was completely broken because of the presence of many impurities in the A. donax hydrolysis residue.…”

Section: Sem Characterization Of Arundo Donax L Hydrolysis Residue Bmentioning

confidence: 91%

See 1 more Smart Citation

Exploitation of Arundo donax L. Hydrolysis Residue for the Green Synthesis of Flexible Polyurethane Foams

et al. 2017

View full text Add to dashboard Cite

Flexible polyurethane foams were prepared from solid waste residue derived from the hydrothermal acid treatment of the Arundo donax L. herbaceous biomass, which produced a very high yield of levulinic acid. An innovative, sustainable, and green liquefaction route was adopted to produce lignin-based flexible polyurethane foams by partially replacing fossil-fuel source polyols with an abundant and renewable hydroxyl source, the Arundo donax L. "lignin-like" residue. Lignin liquefaction was performed in polyolic solvents using microwave irradiation, saving time and energy while ensuring a more sustainable and green approach. Foam production was performed with controlled expansion using the "one-shot" technique. Water was adopted as the only blowing agent, and the isocyanate index (NCO/OH) was kept to less than 100, which reduced the cross-linking degree of the desired foam and increased its flexibility. About 7 wt.% of the conventional petrochemical polyether polyol was replaced with the Arundo donax L. hydrolysis residue. The chemical and mechanical properties of the synthesized foams were compared with those obtained by using a pure technical soda lignin, ProtoBind 1000. The results were characterized by satisfactory mechanical properties, thus closing the biorefinery cycle of Arundo donax L. exploitation.

show abstract

Section: Sem Characterization Of Arundo Donax L Hydrolysis Residue Bsupporting

confidence: 92%

Section: Sem Characterization Of Arundo Donax L Hydrolysis Residue Bmentioning

confidence: 91%

Exploitation of Arundo donax L. Hydrolysis Residue for the Green Synthesis of Flexible Polyurethane Foams

et al. 2017

View full text Add to dashboard Cite

show abstract

“…This is discussed in detail later. The sequence of reactions was studied by a number of investigators using FTIR (11)(12)(13)(14)(15). All investigators observed a growing urea carbonyl absorption at 1715 wavenumbers early in the reaction.…”

Section: Foam Manufacturementioning

confidence: 99%

“…Rossmy and coworkers ( 15) hypothesized that the more reactive para isocyanate groups react first and that when these groups have all reacted, the ortho groups must react leading to larger products which precipitate out. Their statement is pure speculation, but it may be sound.…”

Section: Foam Manufacturementioning

confidence: 99%

See 1 more Smart Citation

Morphology of water‐blown flexible polyurethane foams

Armistead

Wilkes

Turner

1988

J of Applied Polymer Sci

119

View full text Add to dashboard Cite

Committee Chairman: Garth L. Wilkes Chemical Engineering (ABSTRACT)A series of four water-blown flexible polyurethane foams was produced in which the water content was varied from 2 to 5 pph at a constant isocyanate index of 110.A portion of each foam was thermally compression molded into a plaque. The morphology of the foams and plaques was investigated using OMS, DSC, FTI R, TEM, SEM, swelling, WAXS, and SAXS. A high degree of phase separation occurs in these foams and the degree of phase separation is independent of water (ha rd segment) content. In the foam with the lowest water content the morphology is similar to that of typical segmented urethane elastomers. Small hard segment domains are present with a correlation distance of roughly 7. 0 nanometers. When the water content is increased a binodal distribution of hard segments appears.There are the smal I ha rd segment domains typical of segmented urethane elastomers as well as large hard segment aggregates greater than 100 nanometers 1n diameter. The large domains are thought to be aggregates of polyurea that precipitated during the manufacture of the foam. The foam making process successfully incorporated the trifunctional polyols into a network indicating a high degree of polymerization for the hydroxyl-isocyanate reaction. Unreacted isocyanate is present in the foams a month after curing. It is believed to be trapped in the large urea aggregates.WAXS patterns of the foams suggest hard segment ordering that may be of a paracrystalline nature but certainly lacking in true crystallinity. ACKNOWLEDGEMENTSI would like to thank my major professor Dr. Wilkes for his patience, concern, and support, without which I probably would not have remained in Blacksburg to complete this work.I wou Id also Ii ke to thank Dr. Glasser and Dr. Sebba for the interest they showed in my work and the time and effort they spent reviewing my thesis.I would like to thank Rick Allen and Dr. Lin for their assistance in using the ORNL facilities and Dinesh Tyagi and Brandt Carter for many helpful discussions.Finally, I would like to thank all of the group members for their everyday greetings, smiles, and conversion. In particular I would like to thank Dinesh and Ruby, Brandt, Marty and Martha, andBruce.iv One reason for this is that in the production of polyurethane foams, the blowing and gelling reactions occur simultaneously. Any change in chemistry or processing conditions alters both the cell structure and the morphology of the material comprising the cell structure. As a result, there is no way to evaluate the material independent of cell structure or cell structure independent of material. Changes in chemical and processing variables have been extensively studied as to their influence on bulk properties of the foam and polyurethane foams with a wide range of physical properties can be produced ( 1-5).This 'technological' approach to the development of polyurethane foams has been very successful and presently, the yearly production of polyurethane foams far outweighs other types...

show abstract