Chemistry and general applications of thermoset resins

Ratna, Debdatta

doi:10.1016/b978-0-323-85664-5.00006-5

Cited by 23 publications

(27 citation statements)

References 439 publications

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“…Especially their excellent strength to weight ratio in combination with their chemical resistance renders them attractive for high‐performance applications, such as structural building parts, protective coatings, or sealings. [ 1–6 ] Furthermore, covalently crosslinked polymers are widely used as a matrix material for fiber‐reinforced composites, particulate composites, and laminates. [ 7 ]…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, thermomechanical reshaping, welding, and recycling processes, commonly employed for thermoplastic polymers, are not applicable. [ 1–3,8 ] To address these challenges, especially in terms of resource conservation, strategies for combining the beneficial effects of thermosetting (dimensional stability, chemical resistance) and thermoplastic (repairability, recyclability) polymers have been developed. [ 4,5,9,10 ]…”

Section: Introductionmentioning

confidence: 99%

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Thermally Latent Bases in Dynamic Covalent Polymer Networks and their Emerging Applications

et al. 2023

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A novel strategy allowing temporal control of dynamic bond exchange in covalently crosslinked polymer networks via latent transesterification catalysts is introduced. Obtained by a straightforward air‐ and water‐tolerant synthesis, the latent catalyst is designed for an irreversible temperature‐mediated release of a strong organic base. Its long‐term inactivity at temperatures below 50 °C provides the unique opportunity to equip dynamic covalent networks with creep resistance and high bond‐exchange rates, once activated. The presented thermally latent base catalyst is conveniently introducible in readily available building blocks and, as proof of concept, applied in a radically polymerized thiol–ene network. Light‐mediated curing is used for 3D‐printing functional objects, on which the possibility of spatially controlled reshaping and welding based on dynamic transesterification is illustrated. Since the catalyst is thermally activated, limitations regarding sample geometry and optical transparency do not apply, which facilitates a transfer to well‐established industrial technologies. Consequently, fiber‐reinforced and highly filled magneto‐active thiol–ene polymer composites are fabricated by a thermal curing approach. The on‐demand activation of dynamic transesterification is demonstrated by (magneto‐assisted) reshaping experiments, highlighting a wide range of potential future applications offered by the presented concept.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Thermally Latent Bases in Dynamic Covalent Polymer Networks and their Emerging Applications

et al. 2023

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“…Among them, long glass ber reinforced thermoplastic granules are often preferred for different applications due to the advantages such as better mechanics at increased temperatures, less creep, and higher working absorption during impact stress. The pultrusion process, where the ber bundle is pulled through a bath of thermoplastic melt and cut to the desired length, is the main manufacturing method for the long glass ber reinforced polypropylene, and requires expensive tooling [46,47]. The use of GF reinforced thermoplastics in industry brings with it some problems despite the many bene ts that their utilization provides.…”

Section: Benchmarking Study Of Hemp Ber and Glass Ber Reinforced Comp...mentioning

confidence: 99%

Interfacial engineered design of upcycled graphene and hemp fiber reinforced polypropylene compounds as an injection grade for overmoulding process with bio-based prepregs

Aliyeva

Yağcı²,

Şaş

et al. 2023

Preprint

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The design of lightweight composite structures is a principal keystone in improving part performance by reducing adverse environmental impacts and adopting energy-efficient manufacturing technologies. This study replaced long glass fiber reinforced homoPP compounds as an injection grade with short hemp fiber reinforced homopolymer polypropylene (homoPP) by incorporating graphene nanoplatelets (GNP) produced from the source of recycled carbon black coming from pyrolysis of waste tires by providing 15% lightweighting. With new compound formulation by adjusting the amounts of compatibilizer and GNP, injection moulding process was integrated with overmoulding process by using bio-based UD prepregs to enhance the adhesion of injected part and interfacial interaction by decreasing the stress concentrations in the structure. This novel hybrid composite design having 40% hemp fiber, 1.0wt% GNP and 2.7wt% compatibilizer provided to improve flexural modulus and strength by 169% and 67.9%, respectively, compared to neat homoPP. For overmoulding process, bio-based natural fibers reinforced UD tapes were used as an insert and combined with injected hemp fiber reinforced composites with the enhancement of 211% and 93.6% in tensile modulus and strength compared to neat homoPP. This work achieved to convert conventional composite structures into recyclable and sustainable thermoplastic composites having multi-scale reinforcements with tailorable functionality.

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“…Chain extenders, curing agents, or crosslinkers are aromatic or aliphatic low-molecular-weight molecules (amine- or hydroxyl-terminated, with a functionality ≥ 2) that react with polyisocyanates to increase the volume of the segments with lower mobility (HS) to improve the final properties of the PU and PUR products [ 18 ]. In PU and PUR materials, chain extenders typically align themselves with the rigid and largely immobile hard segments inside the polymeric matrix [ 19 ]. In addition, higher functionalities lead to crosslinking between the tangled soft segments (SS) and the hard segments (HS) inside the PU and PUR matrices.…”

Section: Introductionmentioning

confidence: 99%

Effect of Aromatic Chain Extenders on Polyurea and Polyurethane Coatings Designed for Defense Applications

et al. 2023

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The present work describes the synthesis of new versatile polyurea (PU) and polyurethane (PUR) matrices, including different chain extenders, which facilitate the design of distinct, tunable properties, and high-performance derivatives. These polymers can be used for various defense and security applications, such as coatings for ballistic protection, CBRN protection, binders for energetic formulations, etc. Combining aliphatic and aromatic molecules in PU or PUR structures enables the synthesis of polymers with improved and controllable thermo-mechanical properties. Thus, for polyurea synthesis, we utilized two types of polymeric aliphatic diamines and three types of aromatic chain extenders (1,1’-biphenyl-4,4’-diamine, benzene-1,2-diamine, and 1,2-diphenylhydrazine). An analogous method was used to synthesize polyurethane films by employing one polymeric aliphatic polyol and three types of aromatic chain extenders (benzene-1,3-diol, benzene-1,4-diol, and benzene-1,2,3-triol). Subsequently, various analytic techniques (Fourier transform infrared spectroscopy–attenuated total reflectance (FTIR-ATR), single cantilever dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), frequency-dependent shear modulus survey, tensile tests, water contact angle measurements, and scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX)) have been utilized to characterize the synthesized materials and to evaluate the influence of each chain extender on their final properties.

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Chemistry and general applications of thermoset resins

Cited by 23 publications

References 439 publications

Thermally Latent Bases in Dynamic Covalent Polymer Networks and their Emerging Applications

Thermally Latent Bases in Dynamic Covalent Polymer Networks and their Emerging Applications

Interfacial engineered design of upcycled graphene and hemp fiber reinforced polypropylene compounds as an injection grade for overmoulding process with bio-based prepregs

Effect of Aromatic Chain Extenders on Polyurea and Polyurethane Coatings Designed for Defense Applications

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