Structural investigations of toluene diisocyanate (TDI) and trimethylolpropane (TMP)-based polyurethane prepolymer

He, Yong; Zhang, Xinya; Zhang, Xinfang; Huang, Hong; Chang, Jie; Huan-qin, Chen

doi:10.1016/j.jiec.2012.02.023

Cited by 46 publications

(23 citation statements)

References 39 publications

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“…The carbamation of CNCs and the later hydrolysis of the free isocyanates can be confirmed using FT-IR ( Figure 7) by monitoring the appearance and disappearance of NCO asymmetric vibration bands around 2320 and 2370 cm −1 , the urethane carbonyl stretching vibration band at 1720 cm −-1 , and the bands of aromatic ring at 1520 and 1620 cm −1 [29]. The original CNCs showed the typical glycosidic vibration bands ca 1100 cm −1 , the C-H stretching band at 2880 cm −1 , and the O-H stretching band at 3350 cm −1 .…”

Section: Quantification Of the Free Isocyanates Of Tdi-carbamated Cncmentioning

confidence: 87%

A Simple Method for the Quantification of Free Isocyanates on the Surface of Cellulose Nanocrystals upon Carbamation using Toluene Diisocyanate

Abushammala

2019

Surfaces

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In many reports, cellulose and nanocellulose have been carbamated using 2,4-toluene diisocyanate (2,4-TDI) to allow the grafting of molecules or polymers onto their surfaces. Such a process usually involves the reaction of the more reactive isocyanate group of TDI (para-NCO) selectively with a hydroxyl group from the cellulose surface, followed by the reaction of the free isocyanate (ortho-NCO) with a desired molecule. After the first step, it is not possible, using elemental analysis, to determine the amount of ortho-NCO on the cellulosic surface, as an ideal para/ortho selectivity is difficult to obtain. This paper presents a simple method for the quantification of ortho-NCOs on the surface of cellulose nanocrystals upon TDI-based carbamation. It relies on the pH increase upon a complete hydrolysis of ortho-NCOs to amine groups using acidified dimethylsulfoxide. The method was found to be accurate and valid for a degree of substitution of up to 20%.

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Section: Quantification Of the Free Isocyanates Of Tdi-carbamated Cncmentioning

confidence: 87%

A Simple Method for the Quantification of Free Isocyanates on the Surface of Cellulose Nanocrystals upon Carbamation using Toluene Diisocyanate

Abushammala

2019

Surfaces

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“…Its low price and good strength properties of glue lines under dry conditions result in its being widely applied despite its low water resistance 8 . In order to increase water resistance of UF adhesives, they are commonly modified with melamine 9 and diisocyanate 10 . Investigations conducted in this respect showed that the application of melamine and isocyanates in the UF adhesive improved the glue-line strength to a considerable degree and increased water resistance of the UF adhesive 9,10 .…”

Section: Introductionmentioning

confidence: 99%

“…In order to increase water resistance of UF adhesives, they are commonly modified with melamine 9 and diisocyanate 10 . Investigations conducted in this respect showed that the application of melamine and isocyanates in the UF adhesive improved the glue-line strength to a considerable degree and increased water resistance of the UF adhesive 9,10 . However, modifiers are still expensive and increase the cost of UF adhesive.…”

Section: Introductionmentioning

confidence: 99%

Combined effect of thermoplastic and thermosetting adhesives on properties of particleboard with rice husk core

2014

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This study investigated the combined effect of adhesive type and content on the dimensional stability and mechanical properties of three-layer particleboards made from a mixture of wood particles (face layer: 30 wt %) and rice husk particles (core layer: 70 wt %). Two types of thermosetting adhesives, liquid urea-formaldehyde (UF) and phenol-formaldehyde (PF), and thermoplastic adhesive (low density polyethylene: LDPE) powder were used as binder in the experiments. Thickness swelling and water absorption of the particleboards significantly decreased with increasing content of the LDPE powder. The incorporation of LDPE powder into the core layer of particleboard greatly improved the internal bond strength.

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“…TDI-TMP prepolymer was prepared with TDI and trimethylolpropane (TMP) at certain condition [17]. It was the most common polyurethane curing agent and one of the earliest isocyanate prepolymer components [17]. There was a problem of free TDI in the curing agent because TDI was toxic [18,19].…”

Section: Introductionmentioning

confidence: 99%

“…Thin film evaporation was a method of removing free TDI from curing agent under the condition of high vacuum by using outer cooled or internally cooled thin-film evaporator. The low free TDI product has been widely used [17]. The characteristics of high vacuum thin film evaporation are products with low molecular weight, narrow molecular weight distribution, high NCO content and high crosslink density.…”

Section: Introductionmentioning

confidence: 99%

Preparation of branched polyurethane curing agent by condensation polymerization and radical polymerization

Wang

2020

SN Appl. Sci.

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A new PU curing agent with branched structure was prepared by esterification, radical polymerization and reaction of TDI. Unsaturated content (itaconic acid) was added in esterification of adipic acid and 1,4-butanediol, which prepared linear molecule poly (itaconic acid-adipic acid-1,4-butanediol). Then, azodiisobutyronitrile was used to initiate polymerization to form branched molecule (CPBIA). CPBIA reacted with semi-blocked TDI to prepare TDI-CPBIA. These polymers were characterized by FT-IR, 1 H NRM and GPC. Their structure was confirmed. The adjustment of polycondensation and radical polymerization by the raw material ratio and reaction temperature could yield the desired PU curing agent with branched structure and fine solubility. According primary experiments, TDI-CPBIA had fine application performance. The coating had good hardness (6H), thermal performance (T 0 > 250 °C), adhesion (level 1) and impact strength (> 50 cm). This PU curing agent has fine application performance.

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Structural investigations of toluene diisocyanate (TDI) and trimethylolpropane (TMP)-based polyurethane prepolymer

Cited by 46 publications

References 39 publications

A Simple Method for the Quantification of Free Isocyanates on the Surface of Cellulose Nanocrystals upon Carbamation using Toluene Diisocyanate

A Simple Method for the Quantification of Free Isocyanates on the Surface of Cellulose Nanocrystals upon Carbamation using Toluene Diisocyanate

Combined effect of thermoplastic and thermosetting adhesives on properties of particleboard with rice husk core

Preparation of branched polyurethane curing agent by condensation polymerization and radical polymerization

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