Ultraviolet (UV) curing technology has revolutionized the coatings, adhesives, and inks industries over the past few decades. Among the many monomers available to formulators, AM-319 (4-Tert-Butylcyclohexyl Acrylate, or TBCHA) has emerged as a standout performer - a monofunctional acrylate monomer that delivers an uncommon combination of properties: superior adhesion to difficult substrates, outstanding water and chemical resistance, high toughness, and remarkably low skin irritation.
Whether you are developing UV-curable coatings for automotive interiors, formulating inks for flexible packaging, or designing adhesives for electronic assemblies, understanding what AM-319 can bring to your formulation is essential. This guide provides what you need to know about this monomer - from its molecular architecture and key advantages to its applications across industries and how to use it effectively.
At a Glance: AM-319 (TBCHA) Monomer
| Property | Value / Description |
|---|---|
| Chemical Name | 4-tert-Butylcyclohexyl Acrylate |
| CAS Number | 84100-23-2 |
| Molecular Formula | C₁₃H₂₂O₂ |
| Molecular Weight | 210.31 g/mol |
| Appearance | Colorless to light yellow transparent liquid |
| Surface Tension | ~29 dynes/cm |
| Glass Transition Temperature (Tg) | ~72°C |
| Skin Irritation (P.I.I.) | 1.7 (very low) |
| Viscosity | Low (excellent diluent) |
| Stabilizer | MEHQ (200–400 ppm) |
What Is AM-319 (TBCHA)? Understanding the Basics
Chemically known as 4-tert-Butylcyclohexyl Acrylate (CAS RN: 84100-23-2), AM-319 is a monofunctional acrylate monomer - meaning it contains a single acrylate group capable of undergoing free-radical polymerization upon exposure to UV or electron beam radiation. Its unique molecular structure is the key to its exceptional performance.
The molecule comprises three functional regions: an acrylate group responsible for photopolymerization reactivity, a rigid cyclohexyl ring that imparts thermal stability and mechanical strength, and a bulky tert-butyl group that provides steric hindrance, low surface polarity, and hydrophobic character.
Notably, the molecule contains only carbon, hydrogen, and oxygen atoms, with no hydrophilic groups or other heteroatoms (such as nitrogen or sulfur). This simple composition is directly responsible for its outstanding water resistance and chemical durability, while the bulky substituents effectively minimize inter-molecular interactions that typically contribute to skin irritation.
Suppliers such as Shenzhen U-Sunny market this high-purity product as AM-319, and it is also available under trade names including Laromer® TBCH from BASF, SR 217/CD 217 from Sartomer, and Miramer M1150.
Key Properties and Advantages of AM-319
1. Exceptional Adhesion Promotion
Perhaps the most valued property of AM-319 is its ability to dramatically improve adhesion to a wide range of difficult-to-bond substrates. With a low surface tension of approximately 29 dynes/cm, the monomer easily wets and spreads across most non-polar or low-polarity plastic surfaces, effectively penetrating and anchoring to the substrate.
It has demonstrated excellent adhesion performance on:
Polymer substrates: PET, Polyethylene (PE), Polypropylene (PP), Polycarbonate (PC), Polymethyl Methacrylate (PMMA)
Special surfaces: Metal-plated interfaces, glass surfaces, inorganic materials including marble
Coated surfaces requiring primer-less bonding
For applications on plastics traditionally considered challenging without extensive surface pretreatment - such as polypropylene (PP), polyethylene (PE), and thermoplastic polyolefin (TPO) - AM-319 serves as a critical component in primers and direct-to-substrate formulations.
2. Outstanding Water and Chemical Resistance
Because AM-319 contains no hydrophilic groups, the cured polymer network is inherently hydrophobic. This imparts outstanding resistance to water, moisture, humidity, and various chemicals - properties that are vital for applications exposed to harsh environments or requiring frequent cleaning.
The bulky tert-butyl group attached to the cyclohexyl ring further provides steric hindrance, enhancing thermal stability (boiling point: 259.2 °C, operational stability up to 200 °C) and chemical resistance, making it suitable for automotive coatings, aerospace adhesives, and PCB applications.
3. High Toughness Combined with Flexibility
Films formulated with AM-319 are known for their toughness, durability, and impact resistance. The monomer inherently provides a high glass transition temperature (Tg of approximately 72 °C), imparting good rigidity to the coating. Simultaneously, when properly formulated, it can achieve remarkable flexibility - bending without cracking - effectively balancing hardness and toughness.
This combination of rigidity and flexibility is rare in single-functional monomers and makes AM-319 particularly valuable for applications requiring mechanical durability without brittleness.
4. Low Shrinkage and Dimensional Stability
Like many acrylates, UV curing involves volume shrinkage, which can lead to stress and poor adhesion. AM-319 helps reduce overall shrinkage (reported <3 %) in formulations, thereby improving adhesion and maintaining dimensional stability - a critical consideration for precision applications such as optical lenses and flexible displays.
5. Low Skin Irritation and Low Odor
Traditional acrylate monomers often carry significant skin irritation risks, posing health concerns for workers in production environments. AM-319 has been engineered with a significantly reduced primary irritation index (P.I.I.) of 1.7 - a measure of dermal irritation potential - and features a very low odor profile.
This combination makes AM-319 an ideal choice for applications requiring enhanced workplace safety, regulatory compliance (REACH, OSHA), and user-friendly industrial materials. It is particularly valuable for food-contact packaging, consumer goods, and cosmetics where skin contact may be unavoidable.
6. Rapid Cure Speed and Environmental Compliance
AM-319 exhibits high reactivity under UV light, achieving full polymerization in typically less than 30 seconds under 365 nm UV radiation. The monomer is solvent-free with near-zero VOC emissions, is compliant with RoHS and REACH standards, and supports sustainable manufacturing by reducing energy consumption compared to thermal curing systems.
Primary Applications of AM-319 (TBCHA) Monomer
1. UV Coatings
In UV coating formulations, AM-319 serves as a high-performance additive to boost adhesion and water resistance for coatings on plastic housings, automotive interiors, and consumer electronics. It also helps reduce system shrinkage stress and minimize cracking.
For decorative and protective coatings requiring high gloss and weather-resistant finishes, AM-319 delivers durability while maintaining excellent flow and leveling due to its low surface tension. Formulators report 20–30 % improvements in product lifespan and production efficiency when using AM-319-based formulations.
2. UV Inks
AM-319 is ideal for printing on plastic films (e.g., for packaging, labels), coated metals, and glass. It provides the ink layer with necessary toughness and durable adhesion, ensuring long-lasting graphics. The monomer also enhances ink adhesion on non-porous substrates, reducing delamination in packaging and labels.
For UV inkjet printing, AM-319's low viscosity - typically well below 30 cP at 25 °C - makes it highly suitable for inkjet processes, while delivering fast cure speed, broad substrate compatibility, and a tough protective film layer.
3. UV Adhesives
In adhesive applications, AM-319 is used to achieve high-strength adhesion and weather/water resistance, such as in glass assembly or plastic part bonding. Its low odor is also beneficial for VOC-sensitive or enclosed spaces. Within adhesive systems, AM-319 mitigates the brittleness of high-functionality resins, enabling durable bonds in demanding environments including electronics and medical devices.
For pressure-sensitive adhesives (PSAs) and structural bonding systems, TBCHA enhances flexibility and reduces shrinkage during curing - critical for electronics and medical devices where dimensional stability is paramount.
4. 3D Printing Resins
The combination of low viscosity, high toughness, and low shrinkage makes AM-319 highly valuable for photocurable 3D printing resins. The monomer contributes to the production of tough, durable printed parts with high dimensional accuracy - a key consideration for industrial additive manufacturing.
TBCHA-based polymers have also been investigated for shape memory applications in 4D printing, where the ability to precisely tune mechanical properties opens new possibilities for smart materials.
5. Specialty Polymers and Advanced Applications
AM-319 is also used in specialty polymer formulations requiring precise tuning of polymer hardness and glass transition temperatures, including optical films and high-temperature sensor coatings. In advanced display technologies, AM-319-based formulations are used in PCB coatings and flexible displays, leveraging their thermal stability (up to 200 °C). The monomer also finds use in fabricating holographic polymer-dispersed liquid crystal (HPDLC) grating devices.
How to Use AM-319 Effectively in Your Formulation
AM-319 is typically not used as the main resin but as a functional diluent monomer or modifying additive. An addition level of 5 % to 20 % of the total formula weight is often sufficient to significantly improve adhesion and resistance properties.
When developing formulations for difficult plastics, it is recommended to combine AM-319 with suitable oligomers - such as epoxy acrylates, urethane acrylates, or polyester acrylates - and other monomers, followed by systematic adhesion and performance testing to find the optimal balance. For primer applications on low-surface-energy plastics, AM-319 can be applied as a thin coating and UV-cured to form an interfacial layer that dramatically enhances the adhesion of subsequent coatings, inks, or adhesives.
Safety note: While AM-319 has a low skin irritation profile, standard industrial hygiene practices - including the use of gloves and eye protection - should always be followed. The product should be stored sealed, protected from light, away from heat sources, and in a cool, dry, well-ventilated area with appropriate stabilizers.
Technical Specifications Summary
CAS No.: 84100-23-2
Form: Liquid
Surface Tension: ~29 dynes/cm
Tg: ~72 °C
Skin Irritation (P.I.I.): 1.7
Molecular Formula: C₁₃H₂₂O₂
Molecular Weight: 210.31 g/mol
Viscosity: Low (suitable for inkjet)
Cure Speed: <30 seconds (365 nm UV)
Shrinkage: <3 %
VOCs: Near-zero
Shelf life: 12 months (factory sealed, appropriate storage)
Packaging: 25 kg plastic drum, 200 kg iron drum
Conclusion
For formulators seeking to conquer adhesion challenges on difficult substrates while pursuing long-term durability and environmental responsibility, AM-319 (TBCHA) offers a proven and effective solution.
Its unique molecular architecture - combining a rigid cyclohexyl backbone with a bulky tert-butyl group and an absence of hydrophilic functional groups - unlocks advantages that few other monofunctional acrylates can match: exceptional wetting and adhesion to low-energy plastics, outstanding water and chemical resistance, a balance of hardness and flexibility, low shrinkage, rapid cure speed, low odor, and remarkably low skin irritation.
From high-performance UV coatings and durable printing inks to reliable structural adhesives and advanced 3D printing resins, the TBCHA monomer continues to find new applications across industries, including automotive, consumer electronics, packaging, medical devices, and aerospace. As industries increasingly prioritize sustainability and workplace safety alongside technical performance, AM-319 is positioned as a future-proof ingredient for next-generation UV-curable formulations.