Caprolactam-Modified Amino Resins

1、Functional design of caprolactam for aliphatic polyamide with enhanced

In this work, we proposed a novel strategy for improving the flame retardancy while maintaining the recyclability of PA 6 through the rational design of a side-chain functional monomer from ACL.

2、Journal of Applied Polymer Science

The in-situ anionic polymerization of ε-caprolactam (ε-CL) to polyamide-6 enables the production of large, near net shape fiber reinforced composites by thermoplastic resin transfer molding.

Journal of Applied Polymer Science

3、Unveiling the Mechanisms of Hydrolytic Ring

At the M06-2X/6-31+G (d,p) computational level, the reactions hydrolytic ring-opening polymerization of caprolactam to form cyclodimers and amino-assisted ring opening of the cyclic caprolactam dimers were studied in detail.

Unveiling the Mechanisms of Hydrolytic Ring

4、己内酰胺改性酪蛋白与水性聚氨酯的共混物，用于成膜粘合剂

Biodegradable composites of caprolactam-modified casein and waterborne polyurethane (CA-CPL/WPU) for film-forming binder were prepared in composition of 5:5, 6:4, 7:3, 8:2, 9:1 (w/w) via blending. Influences of WPU amount on miscibility, morphology and properties of the composites were investigated.

5、2010年论文

Synthesis of pH responsive hydrophobically modified hydrogels of poly (methacrylic acid-co-diallyl ammonium salt) in aqueous solution. NEW JOURNAL OF CHEMISTRY, 2010, 34 (9): 2034-2039.

Effect of caprolactam modified phenoxy

The caprolactam modified phenoxy-based sizing material for CFRTP produced by the reactive process was designed to adhere strongly to the carbon fiber and concurrently act as an initiator during PA-6 polymerization.

Preparation of a Novel Branched Polyamide 6 (PA6) via Co

In this study, a novel branched polyamide 6 has been synthesized via the hydrolytic ring-opening co-polymerization of ε-caprolactam (CPL) and α-Amino-ε-caprolactam (ACL).

Anionic Ring

To establish optimal conditions for designing an efficient and continuous PA6 production process, this study examines the anionic polymerization of CL at temperatures above the crystallization point of PA6.

A reactive flame retardant based on functionalized α

As a reactive flame retardant, P-Ph-N ACL exhibits excellent flame-retardant performance, thermal stability, and reactivity. A series of copolymerized flame-retardant polyamide (P-Ph-N PA) are synthesized via hydrolytic copolycondensation using ε-caprolactam (CPL) and P-Ph-N ACL as raw materials.

Blend composites of caprolactam

Abstract: This paper reviews the preparation methods, structural characteristics, and applications of caprolactam-modified amino resins in multiple fields. The article first introduces the fundamental knowledge of amino resins, then elaborates on the synthesis processes of caprolactam-modified amino resins, including raw material selection, reaction condition control, and post-treatment techniques. Subsequently, it discusses the structural features of these materials and their impact on performance. Finally, the paper explores their applications in electronics, coatings, composites, and other fields, while highlighting current challenges and future development directions.

Keywords: Amino resins; Caprolactam; Modification; Application

1 Introduction

Amino resins are a class of polymeric materials with unique chemical structures, characterized by amino functional groups that provide excellent adhesion and mechanical strength. They are widely used in construction, automotive, electronics, and other industries. In recent years, advancements in technology have driven the exploration of new materials to enhance the properties of amino resins. Among these, caprolactam-modified amino resins have gained significant attention due to their distinctive properties. These modified resins not only improve water resistance, heat resistance, and mechanical performance but also expand their application range. This paper aims to summarize the preparation methods, structural characteristics, and applications of caprolactam-modified amino resins, while展望未来发展趋势.

2 Fundamental Knowledge of Amino Resins

2.1 Definition and Composition Amino resins are high-molecular-weight compounds containing amino functional groups, typically synthesized via condensation reactions between di- or multi-functional amines and aldehydes or ketones. During curing, ammonia is released as stable ring structures form. The primary function of amino resins is to react chemically with other substances for bonding, fixation, or functional purposes.

2.2 Classification and Characteristics Amino resins can be classified based on chemical structure and functionality:

Chemical Structure: Aliphatic, aromatic, or heterocyclic.
Application: Adhesives, coatings, sealants, etc. They exhibit excellent water resistance, oil resistance, solvent resistance, and thermal stability, enabling broad industrial applications.

2.3 Application Examples Amino resins are extensively used in industries such as:

Construction: Wood furniture adhesives, flooring, and wall bonding.
Electronics: Circuit board adhesives for enhanced reliability.
Automotive: Engine component sealants to prevent leaks.
Aerospace: Aircraft fuselage and engine part adhesives for structural integrity.

3 Preparation Methods of Caprolactam-Modified Amino Resins

3.1 Raw Materials and Reagents The synthesis involves di- or multi-functional amines, aldehydes/ketones, catalysts, and solvents. Amines form the resin backbone, while aldehydes/ketones introduce caprolactam groups. Catalysts accelerate reactions, and solvents affect solubility and processability.

3.2 Preparation Process The synthesis includes:

Raw Material Mixing: Di-/multi-functional amines and aldehydes/ketones are combined in optimal ratios.
Reaction: Catalysts and solvents are added, and the mixture is reacted under controlled temperature and pressure.
Post-Treatment: Washing, drying, and refining yield the final product. Precise control of temperature, time, and stirring is critical for quality.

3.3 Post-Treatment Techniques Post-treatment improves performance:

Thermal Treatment: Enhances curing, mechanical strength, and heat resistance.
Cross-Linking: Forms network structures for improved durability.
Surface Treatment: Coating or calendering adds anti-fouling or wear-resistant properties.

4 Structural Characteristics of Caprolactam-Modified Amino Resins

4.1 Molecular Structure The molecular backbone consists of aliphatic/aromatic amines, while caprolactam units are linked via ester bonds as side chains. This structure provides flexibility, plasticity, and chemical resistance. Adjusting caprolactam content optimizes mechanical and thermal properties.

4.2 Physicochemical Properties Key properties include:

Glass Transition Temperature (Tg): Determines hardness.
Thermal Stability: Ensures safety under high temperatures.
Viscosity, Solubility, Volatility: Correlate with molecular structure and dictate application suitability.

4.3 Mechanical Performance Mechanical strength is tuned by caprolactam content. Key metrics include:

Elastic Modulus: Stiffness.
Elongation at Break: Ductility. Optimization enhances durability and reliability.

5 Applications of Caprolactam-Modified Amino Resins

5.1 Electronics Used as circuit board adhesives, encapsulants, and component fixatives. They offer strong adhesion, electrical insulation, vibration damping, and mechanical protection, prolonging product lifespan.

5.2 Coatings Industry Applied in automotive paints for UV resistance, corrosion protection, and durability. They improve abrasion and chemical resistance, enhancing vehicle longevity.

5.3 Composites As matrix materials, they enhance composite strength, heat resistance, and processability. In aerospace, they bond aircraft fuselages and engine parts, ensuring safety and reliability.

6 Challenges and Prospects

6.1 Current Challenges

Complex Processing: Requires specialized equipment and techniques.
High-Temperature Stability: Limited for extreme environments.
Cost: Higher than conventional resins, affecting market competitiveness.

6.2 Future Research Directions

Synthesis Innovation: Simplify processing to reduce costs.
Structural Optimization: Improve high-temperature stability.
Material Blending: Explore new substrates and additives.
Application-Specific Studies: Tailor properties to market needs.

Caprolactam-modified amino resins demonstrate unique advantages and broad application potential in electronics, coatings, and composites. By addressing challenges and refining their properties, these materials can better meet industrial demands. Future research should focus on optimizing synthesis, enhancing performance, and expanding applications.