FTIR investigations on hydrolysis and condensation reactions of alkoxysilane terminated polymers for use in adhesives and sealants

Huber, Michael; Kelch, Steffen; Berke, Heinz

doi:10.1016/j.ijadhadh.2015.10.014

Cited by 27 publications

(19 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most researchers avoid mentioning the reaction order, and they report the reaction rates qualitatively [21,22,23,24]. A number of researchers reported that the hydrolysis of silanes is first or pseudo-first order with respect to the alkoxysilane [25,26,27,28,29], while the order of the hydrolysis reaction with respect to water varied from 0.8 to 4.4 according to the solvent and catalyst used [4,29,30,31]. The condensation reaction was found to be second order in organosilanetriol, while the order of silicic acid condensation was found to be, respectively, third and fourth order in silicic acid concentration under biological and geological conditions [32,33].…”

Section: Hydrolysis and Early Stage Condensationmentioning

confidence: 99%

“…Mineral acids, such as HCl [30,37,53,54,55,56,57,58], phosphoric acid [38], and hydrofluoric acid [59], as well as organic acids, such as acetic acid [2,23,26,45,60,61,62,63], chloroacetic acid [24], p -toluene sulphonic acid [22], and methane sulphonic acid [21], were also used. Researches also looked at the use of other organic compounds, such as tin alkyl esters [24,28], while boron-based catalysts were used to overcome the toxicity of the tin compounds. Other catalysts that were investigated were potassium carbonate [29], sodium hydroxide [64], and trimethyl amine (TEA) [65].…”

Section: Hydrolysis and Early Stage Condensationmentioning

confidence: 99%

See 1 more Smart Citation

Kinetics of Alkoxysilanes and Organoalkoxysilanes Polymerization: A Review

2019

View full text Add to dashboard Cite

Scientists from various different fields use organo-trialkoxysilanes and tetraalkoxysilanes in a number of applications. The silica-based materials are sometimes synthesized without a good understanding of the underlying reaction kinetics. This literature review attempts to be a comprehensive and more technical article in which the kinetics of alkoxysilanes polymerization are discussed. The kinetics of polymerization are controlled by primary factors, such as catalysts, water/silane ratio, pH, and organo-functional groups, while secondary factors, such as temperature, solvent, ionic strength, leaving group, and silane concentration, also have an influence on the reaction rates. Experiments to find correlations between these factors and reaction rates are restricted to certain conditions and most of them disregard the properties of the solvent. In this review, polymerization kinetics are discussed in the first two sections, with the first section covering early stage reactions when the reaction medium is homogenous, and the second section covering when phase separation occurs and the reaction medium becomes heterogeneous. Nuclear magnetic resonance (NMR) spectroscopy and other techniques are discussed in the third section. The last section summarizes the study of reaction mechanisms by using ab initio and Density Functional Theory (DFT) methods alone, and in combination with molecular dynamics (MD) or Monte Carlo (MC) methods.

show abstract

Section: Hydrolysis and Early Stage Condensationmentioning

confidence: 99%

Section: Hydrolysis and Early Stage Condensationmentioning

confidence: 99%

Kinetics of Alkoxysilanes and Organoalkoxysilanes Polymerization: A Review

2019

View full text Add to dashboard Cite

show abstract

“…ATR-FTIR measurements were used to monitor the progress of synthetic reactions and to characterize the structure of SPUR prepolymers, as well as curing of SPUR films [9,13,15,24]. In particular, it provides a convenient and effective way to characterize the organization and association of polymer chains, in terms of the types and extent of hydrogen bonding interactions [16].…”

Section: Resultsmentioning

confidence: 99%

“…The ATR-FTIR spectra of SPUR 8 before and after cure are compared in Figure 6. The curing process results in decreased intensities of Si–OMe absorbance peaks, which are clearly observed at 774 and 817 cm −1 , and the appearance of siloxane Si–O–Si absorbance peaks (single siloxane bond at 1040–1060 cm −1 and multiple siloxane bonds at 1120–1140 cm −1 ) [9,13,24]. However, the siloxane absorbance peaks are barely noticed, as they overlap with strong signals of C–O–C in polyurethane backbone at 1100 cm −1 .…”

Section: Resultsmentioning

confidence: 99%

“…Towards this end, a number of groups have started to develop moisture-curable silane-terminated poly(urethane-urea)s (SPURs) that consist of a polyurethane backbone terminated by moisture-curable alkoxysilanes [9,10,11,12,13]. Since SPUR contains no isocyanate residues and the curing process of SPUR does not generate carbon dioxide, some deficits inherently present in conventional PURs can also be circumvented.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Synthesis of Low-Viscosity Organotin-Free Moisture-Curable Silane-Terminated Poly(Urethane-Urea)s

et al. 2018

View full text Add to dashboard Cite

This work explores the possibility of synthesizing moisture-curable silane-terminated poly(urethane-urea)s (SPURs) of low viscosity. First, NCO-terminated urethane prepolymers were prepared, followed by silane end-capping. The impact of polyol molecular weight and the ratio of isocyanate to polyol (NCO/OH) on viscosity and the properties of SPUR were examined. As alternatives to the organotin catalysts traditionally used for the polyurethane synthesis and curing processes, bismuth carboxylate catalysts were evaluated. In addition, the effect of organofunctional groups in the aminosilane structure (R1-NH-R2-Si(OR3) 3 ), i.e., R1 (alkyl, aryl or trimethoxysilyl-propyl), the spacer R2 (α or γ) and alkyl group R3 (methyl or ethyl), was examined. The chemical and physical structures of the SPUR were investigated by nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR) and the mechanical properties were evaluated by tensile tests. The results reveal that silane-terminated, moisture-curable polyurethanes can be successfully synthesized and cured with bismuth carboxylate catalysts. SPUR exhibiting low viscosity, with adequate tensile strength and elongation can be prepared using environmentally benign bismuth carboxylate catalyst having a high metal content of 19%-21%, by utilizing secondary aminosilane end-cappers and an optimal combination of the polyol molecular weight and NCO/OH ratio.

show abstract

Wood flour‐high density polyethylene composites: Influence of silanization and esterification on mechanical properties

Bijaisoradat

Liang

Manas‐Zloczower

et al. 2020

J of Applied Polymer Sci

View full text Add to dashboard Cite

Silanization and esterification are strategies used to treat wood flour (WF) to produce surface functionalized hydrophobic WF leading to an improvement in dispersion and compatibility between wood phase and polymer phase. Silanization involves functionalization of alkyl groups by coupling trimethoxy (propyl) silane (MPS), and esterification functionalizes WF with ester groups, using acetic anhydride (Ac). Modified WF was incorporated into recycled high‐density polyethylene (HDPE) to form reHDPE/mod‐WF composite system. Both modifications produced highly hydrophobic WF surfaces which improved the dispersion in the reHDPE matrix; resulting in a significant difference in impact strength, specifically at 20 wt% filler, from 74.5 Jm−1 to 146.3 Jm−1 and 113.5 Jm−1, that is, up to 96% and 52% for MPS‐WF and Ac‐WF, respectively. However, filler agglomeration higher than 20 wt% reduces the composite impact strength. The results herein demonstrate that alkyl‐functionalized WF show excellent dispersion in the reHDPE system and is the preferred technique to improve system mechanical resilience as compared to esterification.

show abstract

FTIR investigations on hydrolysis and condensation reactions of alkoxysilane terminated polymers for use in adhesives and sealants

Cited by 27 publications

References 16 publications

Kinetics of Alkoxysilanes and Organoalkoxysilanes Polymerization: A Review

Kinetics of Alkoxysilanes and Organoalkoxysilanes Polymerization: A Review

The Synthesis of Low-Viscosity Organotin-Free Moisture-Curable Silane-Terminated Poly(Urethane-Urea)s

Wood flour‐high density polyethylene composites: Influence of silanization and esterification on mechanical properties

Contact Info

Product

Resources

About