A new blocking agent of isocyanates

Tassel, Xavier; Barbry, Didier; Tighzert, Lan

doi:10.1016/s0014-3057(99)00271-2

Cited by 40 publications

(19 citation statements)

References 6 publications

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“…Technol., Vol.14, No. 2,2001 Both BaMCO-MMA and BMCO-MMA films were almost soluble in THE even after 3600 mJ/cm2-exposure.…”

Section: Mmamentioning

confidence: 99%

“…Some Isocyanates are protected by nucleophiles such as amines, phenols, l3-diketones, lactams, and oximes. [ 1,2] These Isocyanates are called "blocked" isocyanates because they regenerate the Isocyanates on heating as illustrated in Scheme 1. In order to save thermal energy and avoid the damage of substrates, unblocking at lower temperature is strongly desired.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Curing Systems Using Photolysis of Carbomoyloxyimino Groups and Themally Regenerated Isocyanate Groups.

Suyama¹,

Iriyama²,

Shirai³

et al. 2001

J. Photopol. Sci. Technol.

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“…Technol., Vol.14, No. 2,2001 Both BaMCO-MMA and BMCO-MMA films were almost soluble in THE even after 3600 mJ/cm2-exposure.…”

Section: Mmamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Curing Systems Using Photolysis of Carbomoyloxyimino Groups and Themally Regenerated Isocyanate Groups.

Suyama¹,

Iriyama²,

Shirai³

et al. 2001

J. Photopol. Sci. Technol.

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“…36 TCP-blocked TDI-BPUMs were initially de-blocked at about 75 C, and the range of de-blocking temperature was about 70-120 C, and HDI-BPUMs could be initially de-blocked at about 80 C and the de-blocking temperature range was about 80-125 C, which were lower than those of other blocking agents of blocked diisocyanate adducts (110-145 C). 8,37 Moreover, it was found that the low initial deblocking temperatures of the blocked isocyanate series TR1, TR3, TR4, TD1 and TD3 were due to the presence of aromatic ring in the structures and the high initial de-blocking temperature of the blocked isocyanate series HR1, HR3, HR5, HD1 and HD3 were due to the use of aliphatic isocyanates. Among the isocyanate used, TDI based blocked isocyanate undergo deblocking at lowest temperature and are due to the methyl group present in the isocyanate moiety, which accelerates the deblocking reaction, through steric factor.…”

Section: Stabilization Mechanismmentioning

confidence: 99%

Synthesis and stability research of reproducible aqueous polyurethane micelles with low de‐blocking temperature

Zhu

et al. 2015

J of Applied Polymer Sci

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Aqueous polyurethane micelles from 2,4,6-trichlorphenol blocking terminal-isocynate pre-polymer were prepared which could be de-blocked at low temperature. The prepared aqueous blocked polyurethane micelles (BPUMs) were uniform and spherical micro-particles. The particle size was decreased with increase of the DMPA content, while it was enlarged at first and then gradually decreased by increasing R-value. The stability of the micelles was affected by the R value, blocked efficiency and DMPA content. HDIBPUMs were more stable than HDI-BPUMs at the same condition. The stability was further researched by the zeta potential combining with technique and viscosity tracking method, and the initial zeta potential be used as the stability criterion. In addition, a stabilization mechanism of the micelles was proposed. TCP-blocked TDI-BPUMs could be initially de-blocked at about 75 C and TCPblocked HDI-BPUMs was de-blocked at about 80 C. The de-blocking temperature could be further reduced in the presence of catalyst, but it was scarcely affected by the change of R-value and DMPA content.

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“…An elegant solution to overcome all these problems is the use of blocked isocyanates (BIs) . In BIs, the reactivity of the isocyanates is temporarily reduced.…”

Section: Introductionmentioning

confidence: 99%

Lysine‐based functional blocked isocyanates for the preparation of polyurethanes provided with pendant side groups

Yin

Wildeman

Loontjens

2015

J. Polym. Sci. Part A: Polym. Chem.

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This article describes a methodology to prepare polyurethanes (PUs), decorated with pendant (bio)functional side groups, by polymerizing (bio)functionalized blocked diisocyanates with polyols. Caprolactam blocked lysine diisocyanate methyl ester (BLDI-OMe) was prepared in high yields, by reacting the methyl ester of lysine with carbonyl biscaprolactam. In the absence of a catalyst, the polymerization of BLDI-OMe with polycaprolactone and polytetrahydrofuran resulted in strictly linear PUs due to the high selective reactivity of the blocked isocyanates (BIs). Although the ester appeared to be less reactive, we found hydrolyzing conditions for the ester, without affecting the BIs. The free acid groups were converted into a N-hydroxysuccinimide (NHS) activated ester, which was a versatile intermediate for further functionalization. After having demonstrated that model amines were able to substitute NHS without effecting the BIs groups, the same chemistry was used to couple biotin, giving a biotin functional caprolactam blocked lysine diisocyanate. The polymerization with polyols afforded the corresponding biotin-functional PUs.

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A new blocking agent of isocyanates

Cited by 40 publications

References 6 publications

Curing Systems Using Photolysis of Carbomoyloxyimino Groups and Themally Regenerated Isocyanate Groups.

Curing Systems Using Photolysis of Carbomoyloxyimino Groups and Themally Regenerated Isocyanate Groups.

Synthesis and stability research of reproducible aqueous polyurethane micelles with low de‐blocking temperature

Lysine‐based functional blocked isocyanates for the preparation of polyurethanes provided with pendant side groups

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