Rheological study of crosslinking and gelation in bismaleimide/cyanate ester interpenetrating polymer network

Hu, Xiao; Fan, Jing; Yue, Chee Yoon

doi:10.1002/app.1350

Cited by 81 publications

(53 citation statements)

References 21 publications

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“…The gel point in rheological experiments is determined using various methods, according to different definitions [42,43]: the divergence point or fixed level of the viscosity [44,45], the crossover point of the dynamic storage modulus (G') and loss modulus (G") [46], or the point at which the loss tangent becomes independent of testing frequency [47][48][49][50]. The gel point for NPU-2d, as the crossover point of G' and G" appears at 116.5°C as can be seen in Figure 8a.…”

Section: Rheological Behaviourmentioning

confidence: 99%

Polyurethanes based on thermoreversible networks designed by Diels-Alder reaction

Ursache¹,

Găină²,

Gaina³

2017

Express Polym. Lett.

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Polyurethanes appeared as a Bayer's response to the successful development of high molecular weight polyamides by E.I. Dupont, given the competition between the two companies. The need for PUs steadily increased ever since then, because of its high abrasion, chemical resistance, flexibility, and good mechanical property [1]. Nowadays they are considered one of the most versatile polymeric materials class since they can be used in many forms and in a large number of applications including elastomers [2][3][4][5], flexible and rigid foams [6][7][8], biomedical applications [9][10][11], adhesives and coatings [12][13][14], polymers for electronics [15], etc. The reaction between diisocyanates or multiisocyanates and di-or polyols generates polyurethanes with different molecular structures varying from linear to crosslinked ones depending on the structure, functionality and stoichiometry of the reactants. These thermosetting polymers cannot be reprocessed or reused if, according to the desired applications, chemical crosslinkers are used [16]. For de-crosslinking of polyurethane networks, dynamic covalent chemistry is used, especially by means of the DA and retro-DA (rDA) reactions [17]. Due to its reversibility the DA reaction also represents a choice to create self-healing properties for polymer networks [18]. Concerning polyurethane, the DA reaction was employed in thermally remendable linear polymers [19][20][21][22] and thermally reversible networks [23][24][25][26][27]. The latter were designed in three different ways: i) by polymerization reaction of monomers containing maleimide-furan cycloadduct [26,28], ii) by crosslinking of linear polyurethane containing furan or maleimide pendant groups [27,29,30] and iii) by cycloaddition DA reaction between polyurethane containing furan end groups and multimaleimide monomers [19,[23][24][25][31][32][33]. Abstract. Urethane bismaleimides (BMIs) were used in order to obtain crosslinked structures by their reaction with an aromatic trifuran compound. The Diels-Alder (DA) reaction between the maleimide and furan moieties was investigated using proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy for a model compound (CTF), due to the fact that the networks are insoluble in usual NMR solvents. The structure of the networks was confirmed by infrared spectroscopy. Thermal properties were investigated (by means of differential scanning calorimetry (DSC) and thermogravimetrical analyses (TGA)) and compared with the ones of similar compounds, previously obtained from the same BMIs and a different trifuran compound (which contains tertiary nitrogen in its structure). Mechanical and rheological properties were also investigated. The influence of the nature of the polyol from the BMIs structure and/or the influence of using a trifurylic compound with or without tertiary nitrogen on the properties of the crosslinked networks were also discussed.

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Section: Rheological Behaviourmentioning

confidence: 99%

Polyurethanes based on thermoreversible networks designed by Diels-Alder reaction

Ursache¹,

Găină²,

Gaina³

2017

Express Polym. Lett.

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“…Rheological properties such as the viscosity and the dynamic modulus can be directly correlated to the envolving physical and mechanical properties during resin cure (Hu et al, 2001). Viscosity of a paint binder affects flow properties such as leveling and sagging (Lowel, 1990).…”

Section: Gel Time and Viscositymentioning

confidence: 99%

“…Water uptake affects vital properties of the polymer material such as physical, mechanical, thermal and structural properties (Hu et al, 2001 andNogueria et al, 2001). In the paint making industry, the moisture uptake of the binder is very crucial because it is responsible for blistering and broominess of paint film .…”

Section: Moisture Uptakementioning

confidence: 99%

“…It is observed that the moisture uptake increases with increase in the degree of substitution and decrease with increase in alkyl length of the aldehydic group. The increase in water uptake with increase in the degree of substitution is attributed to the increase in OH group while the decrease in moisture uptake with increase in alkyl length of the aldehydic group may be due to the differences in chain topology which is related to the molecular size holes in the polymer structure which also depend on morphology and crosslinked density (Nogueira et al, 2001;Hu et al, 2001).…”

Section: Moisture Uptakementioning

confidence: 99%

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Development of amino resins for emulsion paint formulation: effect of aldelhydic group and degree of substitution

Barminas¹

2007

Afr. J. Biotechnol.

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In our continuous effort to develop a paint binder from amino resins, amino resins from different aldehydic groups were synthesized to produce urea, formaldehyde (UF), urea acetaldehyde (UA), urea proparaldehyde (UP) and urea butaldehyde (UB) at different degree of substitution (Mono -tetra). Some physical properties of these resins were evaluated. The viscosity, gel time, density and refractive index of the resins (except UB) were found to increase with increase in alkyl length of the aldehydic group while turbidity (except UF) increased with increase in alkyl length of the aldehydic group. On the other hand, melting point and moisture uptake decreases with increase in alkyl length of the aldehydic group. In the case of the degree of substitution the viscosity, turbidity, melting point and moisture uptake increases with increase in the degree of substitution while the gel time and refractive index were found to decrease with increase in the degree of substitution. However, an initial rise followed by a gradual fall was recorded for density for the different degree of substitution for all the resins. Samples for UF and UA with the exception of monoethylol urea were too hard brittle and has low water resistance while those of UP and UB resins were too soft and remained as semi solid in the cured state at room temperature (30 o C). This result indicates that these resins cannot be used alone as paint binder. However, monoethylol urea seems to have sieved itself out as a compromise candidate who is neither brittle nor too soft. A comparison of monoethylol urea with some physical properties of some convectional paint binders present it as a potential binder which may be used in the coating industry.

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“…These two drawbacks are due to the high density of crosslink and high crystalline content. Many investigations have been done or are focused on improving its properties in order to increase the application [1][2][3][4][5][6][7]. Other papers have shown the cure mechanism and kinetics for BMI and modified BMI systems during thermal curing [2,[8][9][10].…”

Section: Introductionmentioning

confidence: 99%

UV curing of a liquid based bismaleimide-containing polymer system

Fan¹,

Boey²,

Abadie³

2007

Express Polym. Lett.

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Abstract.A new liquid formulation of commercial bismaleimide and n-acryloylmorpholine was prepared that could be UV cured as an alternative to traditional thermal cure methods presently used for BMI in the industry. UV curing was shown to be an efficient method which promoted the reaction rate significantly and was able to achieve this at low temperatures (30-50°C). A free radical polymerization approach has been used to explain the cure mechanism and cure kinetics, using data elucidated from the DPC and FTIR. The cured thin film was shown to achieve very high thermal stability (~400°C), with the BMI shown to retard the thermal degradation temperature and rate.

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Rheological study of crosslinking and gelation in bismaleimide/cyanate ester interpenetrating polymer network

Cited by 81 publications

References 21 publications

Polyurethanes based on thermoreversible networks designed by Diels-Alder reaction

Polyurethanes based on thermoreversible networks designed by Diels-Alder reaction

Development of amino resins for emulsion paint formulation: effect of aldelhydic group and degree of substitution

UV curing of a liquid based bismaleimide-containing polymer system

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