INTRODUCTION:

Cardolite is a global leader in developing renewable, high performance materials derived from cashew nutshell liquid (CNSL), a non-food, bio-based raw material. With decades of expertise in CNSL chemistry, Cardolite has pioneered a range of technologies that offer sustainable alternatives to petroleum- based systems across coatings, adhesives, composites, foams, and friction materials.

At the core of Cardolite's innovation are its CNSL-based curing agents, diluents, polyols, and modifiers. Products made with CNSL technology provide fast curing, corrosion protection, and excellent low-temperature performance for epoxy coatings without compromising on sustainability. Cardolite also offers CNSL-based polyols and diols for high-bio-content polyurethane systems, supporting greener foam and adhesive technologies.

Through advancements like Ultra LITE and hydrogenated CNSL derivatives, Cardolite has expanded the aesthetic and functional versatility of bio-based materials, offering lighter color, enhanced UV resistance, and lower VOCs. These solutions not only improve environmental performance but also meet demanding industrial requirements.

With production and R&D centers worldwide, Cardolite continues to drive the transition toward circular, low-carbon material solutions supporting the growing global demand for sustainable chemistry. This article emphasises on the novel phenalkamide technology.

RESULTS AND DISCUSSION:

Basic properties of Phenalkamide Curing Agents:

Phenalkamides are a next-generation class of epoxy curing agents developed by Cardolite. They are engineered by chemically merging the properties of phenalkamines and polyamides, creating a hybrid that delivers enhanced performance with broader applicability.

Key Features & Benefits:

·       Fast curing and excellent low-temperature performance, similar to phenalkamines.

·       Superior, anti-corrosion and adhesion capabilities, with strong colour stability and overcoatability.

·       Light-coloured formulations, improving aesthetics and easier application in various conditions.

Advantages for Coatings and Adhesives:

·       Eliminates the need for separate 'summer' and 'winter' converter packages by offering all season versatility and a wider formulation window.

·       The solvent free, low VOC grade offers low viscosity, excellent compatibility with common epoxies (Bis-A, Bis-F), and no induction time required making it optimization friendly for formulators.

·       Ideal for universal use systems across marine, industrial, transportation, and flooring applications, with high adhesion, fast cure, and robust corrosion protection.

LITE 3008: A CHAMPION PHENALKAMIDE

Cardolite LITE 3008 is a specially formulated phenalkamide epoxy curing agent specifically designed as a cost effective alternative to traditional high molecular weight polyamide curing agents. It is well suited for both coating and adhesive applications.

LITE 3008 provides faster cure even at low temperature compared to conventional polyamide samples, which favours quicker project completion, reduced downtime, and earlier return to service while maintaining good film properties. The key benefits are as follows-

·       Quick return to service - Equipment, floors, or structures can be used sooner.

·       Reduced contamination risk - Less time for dust, insects, or debris to settle on the wet film.

·       Weather resistance - In field jobs, protection against rain, dew, and humidity kicks in quickly.

·       Short recoat windows – Multiple coats can be applied in a single shift.

A clear and non-blush film ensures the coating cures to a smooth, defect-free finish with strong intercoat adhesion, consistent appearance, and long-term durability – especially critical for marine, protective, and decorative coatings applied in challenging conditions (Figure 3). Non-blush curing agents perform well even in high humidity or low temperature, avoiding moisture-induced defects.

Pendulum hardness is a useful method to assess the development of crosslink density and the coating's ability to resist scuffing during the early cure stage, as the measurement also reflects the material's resistance to small scale deformation. Results depicted in Figure 4 indicate a similar trend observed with linear dry times.

Interestingly, despite faster curing and hardness development due to rapid crosslinking, the cured system retains flexibility comparable to polyamide-cured systems - a distinctive advantage of Phenalkamide technology (Table 3).

Furthermore, the long-term corrosion protection performance of the curing agent was evaluated using salt spray tests. Test panels were prepared at low to medium film thicknesses and exposed in a salt spray chamber. LITE 3008 demonstrated excellent corrosion resistance compared to standard Polyamide 115 samples. Notably, these panels were formulated without any anti-corrosion pigments. The outstanding protective properties of LITE 3008 can be attributed to the unique structural features derived from its CNSL component- particularly its inherent hydrophobicity and exceptional adhesion to the substrate.

Chemical resistance enables a protective coating to maintain its barrier properties, structural integrity, and performance when exposed to harsh chemicals ensuring safety, durability, and cost efficiency. Phenalkamides generally exhibit superior chemical resistance compared to their polyamide counterparts, primarily due to the aromatic ring in the structural backbone derived from cardanol (Figure 6).

LITE 3008 advantages in a nutshell -

1. Faster cure than Polyamide counterparts
2. Deliver highest level of hardness development
3. Promote higher long term corrosion protection
4. Provide excellent overall chemical resistance to a variety of chemicals
5. Mechanical properties remain uncompromised
6. Excellent Lap Shear Strength over steel and aluminium substrate.

CONCLUSION:

Cardolite's innovative technologies, rooted in the unique chemistry of cashew nut shell liquid (CNSL), deliver sustainable, high-performance solutions for the coatings, adhesives, and composites industries. By combining bio-renewable feedstocks with advanced formulation expertise, Cardolite offers products that meet stringent environmental regulations while enhancing durability, chemical resistance, and application versatility. From phenalkamide curing agents to specialized epoxy modifiers and surfactants, Cardolite's portfolio exemplifies the balance between sustainability and performance, enabling formulators worldwide to create next-generation systems that are safer, more efficient, and environmentally responsible.