1,8-DIAMINO-P-MENTHANE for Scalp Conditioning Anti-Dandruff Itch Relief and Sebum Balancing

1. Description

1,8-Diaminop-menthane is an alicyclic diamine organic compound that typically exists as a mixture of cis and trans stereoisomers. It appears as a colorless to yellow transparent liquid with a density of approximately 0.914 g/mL (at 25°C), a melting point of −45°C, and a boiling point of 107–126°C (under 10 mmHg). This compound possesses a menthane skeleton and belongs to the monoterpene class. It contains a primary amino group at each end of the molecule. Since both amino groups are attached to tertiary carbon atoms, significant steric hindrance confers unique reactivity to the compound. Storage conditions require sealed storage at room temperature. This compound readily absorbs carbon dioxide from the air, so precautions against moisture must be taken. This compound is a refined product of turpentine, derived from pinene found in natural pine trees, and is a bio-based platform compound.

2. Application

(1) Epoxy Resin Hardener: Used as a high-performance epoxy resin hardener, with a recommended usage rate of 22–24 parts by weight. Curing conditions are 80°C for 2–4 hours or 150°C for 1 hour. The cured product exhibits excellent thermal stability, with a heat deflection temperature ranging from 148–158°C. It is widely used in epoxy composite materials, cold-mix epoxy coatings, and other applications.

(2) Polyurethane Raw Material: Used as a bio-based monomer for the synthesis of 1,8-menthane diisocyanate, which serves as an ideal bio-based alternative to petroleum-based isophorone diisocyanate. It can be used to prepare materials such as polyurethane coatings, adhesives, elastomers, and thermoplastic polyurethanes.

(3) Synthesis of Schiff Bases and Metal Complexes: Acts as a bifunctional linker for the synthesis of various Schiff base derivatives. These Schiff bases can form coordination complexes with metal ions such as Cu(II), Zn(II), Cr(III), Fe(III), and Co(III), making them of research value in the fields of coordination chemistry and catalysis.

(4) Antimicrobial and Bioactive Research: Possesses antimicrobial activity and can be used as an antimicrobial agent in daily chemical products such as soap, holding potential application value in the biomedical field.

(5) Carbon Dioxide Capture Research: When blended with AMP (2-amino-2-methyl-1-propanol) as a novel absorption solvent, it is used in research on carbon dioxide capture technologies.

(6) Polyamide and Fiber Modification: It is used to prepare polyamide resins and, as a copolymer monomer, to improve the dyeing properties of polyolefin textile fibers.

3. Main Efficacy

(1) Efficient curing of epoxy resins: As an alicyclic diamine curing agent, the two amino groups undergo an addition reaction with the epoxy groups to form a three-dimensional cross-linked network structure. Due to the presence of a rigid cyclohexane backbone in the molecular structure, the cured product exhibits a high heat deflection temperature (148–158°C) as well as excellent mechanical properties, chemical resistance, and electrical insulation.

(2) Bio-based Isocyanate Precursor: Through a phosgene-free method (using di-tert-butyl dicarbonate), it can be converted into 1,8-menthane diisocyanate. This bio-based diisocyanate has a structure similar to that of petroleum-based isophorone diisocyanate and can be used as a substitute in polyurethane synthesis, promoting the sustainable development of the polyurethane industry.

(3) Coordination Chemistry and Catalysis: As a bidentate ligand precursor, the synthesized Schiff base ligand can form stable complexes with various transition metal ions, demonstrating application potential in fields such as homogeneous catalysis and materials science.

(4) Antimicrobial Activity: Studies indicate that this compound exhibits broad-spectrum antimicrobial activity, acting by disrupting the structure of microbial cell membranes, and can be used as an antimicrobial ingredient in personal care products.

(5) CO₂ Absorption Enhancement: As a steric hindrance amine, when blended with AMP, it can increase CO₂ absorption rates and absorption capacity, making it valuable for research in carbon capture technologies.