Triallyl Isocyanurate TAIC®

Product Description

TAIC® is the trade name of the product TRIALLYL ISOCYANURATE.

TAIC® is a symmetric polyfunctions triazine compound which has been used for the crosslinking reaction of synthetic rubbers and plastics as well as a raw material for flame retardant. TAIC® possesses a thermally stable triazine ring and unique properties, providing a polymer with improved properties, including heat resistance, mechanical properties and resistance to hydrolysis and weathering.

Properties of TAIC®
C.A.S. No.  1025-15-6
TSCA No.  1025-15-6
EINECS No.  2138347
Appearance Slightly yellowish and transparent liquid above 30°C
Specific Gravity (D) See Fig. 1
Boiling Point 144°C at 3 mmHg (see Fig. 2)
Flash Point 245°C by Pensky-Martens method
Viscosity See Fig. 3
Specific Heat 0.6 cal/g °C at 40°C
Refractive Index (nD30) 1.5070-1.5100
Solubility
Water 0.34% at 30°C
n-Pentane Slightly soluble
Ethylene Glycol Slightly soluble
Benzene Soluble
Xzylene Soluble
Methanol Soluble
Methly Ethyl Ketone Soluble
Heptane Soluble

Fig. 1 Specific Gravity of TAIC® Fig. 2 Vapor Pressure of TAIC®
Fig. 3 Viscosity of TAIC®
Fig. 4 Infrared Spectrum of TAIC®

Reactivity of TAIC®

A. Polymerization Reaction

TAIC® is a poly-functional allylic monomer and is easily polymerized by using radical polymerization catalyst such as organic peroxide and azocompound.

TAIC® is less reactive than other vinyl-type monomers. Q and e values of TAIC® are 0.011 and -0.60 respectively. (1)

The heat of polymerization is 55.5 Kcal/mol.

1) Bulk Polymerization

In the reaction of bulk polymerization by using peroxide catalyst, TAIC® provides such a transparent and hard but brittle homopolymer, which has very excellent heat resistance such as that only 5% of weight loss at 400oC in nitrogen atmosphere by thermal gravimetric analysis. (Fig. 5)

Fig. 5 Thermal Analysis of TAIC® Homopolymer
Operation Condidtions Sample Weight 15mg TGA: Thermal Gravimetric Analysis
  Sample Cell Pt DTA: Differential Thermal Analysis
  Reference Material Al2O3  
  Heating Rate 10°C/min.  

2) Solution Polymerization

The polymerization of TAIC® in common solvents provides homopolymers having particularly high melting points. (2)

When the polymerization of TAIC® is carried out in solvent such as halogenated hydrocarbons or aldehydes, linear polymers may be produced by the telomerization with free radical of the solvent. By taking advantage of this telomerizarion, prepolymers which have molecular weith of 6,000 to 9,000, melting point of 120 to 150°C and bromine value off 25 to 35 can be produced. (3)

3) Copolymerization

TAIC® can be copolymerized with many vinyl and allyl type monomers to give copolymers having different properties. (Fig. 6) (4) The copolymerization of TAIC® with other vinyl type monomer is camparatively difficult to be proceeded, however, TAIC® can be used practically for over various fields of application in which small amount of TAIC® participation is enough for the purposes. The copolymers thus produced has higher melting point and specific properties.

Fig. 6 Copolymer Composition Curves of TAIC®

B. Crosslinking Reaction

TAIC® is broadly utilized as a crosslinking coagent for peroxide or radiation crosslinking of polyolefines and synethetic rubbers.

Main role of a crosslinking coagent is inprovement of the crosslinking efficiency by behaving longer life radicals vai primary radicals. The effectiveness of allylic crosslinking coagent is much more superior to vinyl compound by following reasons:

a) Radicals created in allylic compounds are stabilized by the allyl resonace, density of radical in the system is kept in high level.

b) In case of vinyl monomer, the polymerization takes place easily among mutual monomers and so the effectivness to crosslinking reaction will turn worse.

TAIC® can be combined with rubber molecule by crosslinking reaction and improve physical properties include heat resistance, weathering resistance and resistance to oil.

TAIC® is employed as a crosslinking coagent for halogen containing rubbers such as chlorinated polyethylene (CPE) and fluoroelasteomer, some parts of allyl double bonds left in the crosslinking system act as the acceptor of acidic substances such as HCI and HF liberated from the rubber, and physical properties of crosslinked rubber is much improved.

C. Addition Reaction

Addition reaction to double bonds of TAIC® takes place in the same way as to common olefine compounds.

Halogenated TAIC® such as Tris (2,3-dichloro propyl) isocyanurate and Tris (2,3-dibromopropyl) isocyanurate are important compounds as flame retardants for plastics. (Table 1)(5)

Table 1 Properties of Halogenated TAIC®
X Br CL
Molecular Weight 729 462
Melting Point (°C) 110-120 94-96
Content of Halogen (WT%) 66 46
Cyclopentadiene can be added to TAIC® by Diels Alder's reaction.

Product Specifications
TAIC®
Appearance Slightly yellowish and transparent liquid state in summer and white solid in other seasons
Color (APHA) Max. 70
Specific Gravity (30°C) 1.15 - 1.17
Viscosity (30°C, cp) 80 - 110
Melting Point (°C) 23 - 27
Moisture (%) Max. 0.1
*Di-t-butyl hydroxy toluene (BHT) is added as much as 100 ppm to TAIC® as a stabilizer

Application of TAIC®

A. Crosslinking Coagent

TAIC® is widely used as a coagent for peroxide crosslinking or radiation crosslinking of Chlorinated Polyethylene (CPE), EPDM, Fluroelaster and so on.

1) Polyolefines

TAIC® is availavle for linking by x-ray, y-ray electron or ultra violet ray radiation and the product polyolefines have the superior insolubility to solvents and the tensile strength at high temperature could be improved. (6)

2) Chlorinated Polyethylene (CPE)

TAIC® is effective modifier to heat resistance with increasing of crosslinking density for peroxide crosslinking denisty for peroxide crosslinking of CPE. Since TAIC® acts as an acceptor of HCI which is envolved from CPE at crosslinking reaction and deterioriates its physical properties. Table 2 is an example of crosslinking of CPE using TAIC® (7).

3) Ethylene Vinyl Acetate Copolymer (EVA)

TAIC® is the most effecdtive coagent for crosslinking EVA. The effectivness of crosslinking coagent which acts in peroxide crosslinking of EVA is as follows; (10)

TAIC® = TAC > DVB => TMPTMA = DAP = EGDM > NON

TAIC®: Triallyl isocyanurate
TAC: Triallyl cyanurate
DVB: Divinyl Benzen
TMPTMA: Trimethylolpropane trimethacrylate
DAP: Diallyl phthalate
EGDM: Ethyleneglycol dimethacrylate
NON: None of crosslinking coagent

And Fig. 7 shows the relation of Tensile strentgth vs Elongation of crosslinked EVA using some crosslinking coagent. (8)

4) EPDM

EPDM is being widely utilized for industrial use based on its excellent properties on heat resistance and weathering. In application field being required severe physical properties, peroxide crosslinking in employed. TAIC® preferably contributes to promote crosslinking rate and also to improve its heat resistance, compression set and abrasion resistance.

Table 2 - Example of Compounding of CPE
Formulation ELASLEN
401A
ELASLEN
TR
ELASLEN*1 401A 100  
ELASLEN*1 TR   100
Barium Sulfate 30 30
Titanium Dioxide 25 25
Calucium Silcate 25 25
Chlorinated Paraffin 10 10
Paraffin Wax (Antioxdant) 3 3
TAIC® 3 3
Perhexa 2,5B-40*2 5 5
Moony Viscosity ML1+4 121 °C 68.5 37.5
Tensile Properties    
100% Modulus (kg/cm2) 25 22
300% Modulus (kg/cm2) 106 95
Tensile Strength (kg/cm2) 190 148
Elongation (%) 450 470
Hardness Hs 60 60
Compression Set (100°C, 70 hrs) (%) 20.7 16.7
Elongation Change in Chemicals (Room Temp, 14 days) (%)    
Nonionic Soap ± 0 ± 0
Ammonia Water 26% ± 0 ± 0
Acetic Acid 90% -20 - 15
Hydrogen Peroxide 10% ± 0 - 6
Sodium Hypochlorite 13% - 5 - 10
Nitric Acid 40% - 2 - 5
Hydrochloric Acid 35% ± 0 - 2
Sulfuric Acid 50% - 7 - 4
Volume Change in Oil (100% , 70 hrs) (%)    
ASTM #1 - 3.0 ±15.7
ASTM #2 + 14.8 + 41.2
ASTM # 3 40.1 + 70.0
Charge in Heat Ageing (100°C, 98 hrs)    
Tensile Strength (%) - 5 + 3
Elongation (%) - 7 - 6
Hardness (Point) + 3 + 3
*1: CPE/SHOWA DENKO CO., LTD.
*2: 2,5-dIMETHYL 2,5 - di-(t-buryl peroxy) hexane (40%)

Fig. 7 Effect of Crosslinking Coagents on Peroxide Vulcanization of EVA
Formulation:
EVATHLENE 410 100 PHR
Stearic Acid 1
HAF Carbon 50
Zinc Oxide 5
Dicumyl Peroxide 1
Coagent 1/270 mol.
Vuylcanization, Condition 180°C X 10 min

5) Fluoroelastomer
TAIC® is necessarily used for crosslinking reaction of Fluoroelastomer. TAIC® is employed often for radiation crosslinking coagent for specified application field of high quality insulating material. Table 3 is an example of crosslinking of Fluoroelastomer using TAIC®. (9)

6) Urethane Rubber
TAIC® is effective to improve of crosslink density in the vulcanization of millable type polyurethane.

B. Polymerization Comonomer
The copolymerization of bi-functional monomer with TAIC® provides a copolymer crosslinkable by pendant allyl groups in TAIC® unit. Copolymer having higher concentration of TAIC® unit, provide a thermosetting characteristic. The copolymerization will result the improved properties of resistance to heat and weathering and mechanical strength.

1) Emulsion Copolymerization
In emulsion copolymerization of acrylic ester with TAIC®provides an unique copolymer which has much improved properties including heat, weathering and inmpact resistance and it is used as a raw material of acrylic paint and also used as a component for acrylic graft copolymer. TAIC® can also improve properties of copolymer which is made by emulsion copolymerization with styrene or acrylonitrile (10)

2) Copolymerization with Thermosetting Polymer
In addition of TAIC® in unsaturated polyester of fiallyl phthalate prepolymer, heat resistance, hydrolysis resistance and mechanical strength are much improved. (11)

Fig. 8 shows the Heat Deflection Temperature (HDT) of copolymer provided by copolymerization of diallyl phtalate prepolymer and TAIC®.

3) Photopolymerization
TAIC® can rapidly react with poly-thiol compounds by ultraviolet light to provide tightly crosslinked polymeric system. (12) TAIC® can be participated in the photopolymerization of epoxy acrylates. (15)

Fig 8. Effect of TAIC® on HDT of Diallyl Phthalate Polymer

Handling Information
Packaging of TAIC®
20 kg and 200 kg Drum
Toxicity of TAIC®
Acute Oral Toxicity Ld 50 (mouse) 666 mg/kg (14)
Acute Toxicity to Orange-red Killfish (15) LC50, 48 hrs 275 mg/l
LC50, 96 hrs 238 mg/l
Mutagenic Potential None (16)
Skin Irritation None (17)
Eye Irritation None (18)
Care in Handling and Storage of TAIC®
TAIC® has almost no toxicity, however, it is recommended that gloves and safety goggles be worn to handle it. If skin is contaminated by TAIC®, it must be rapidly washed off.

Since as much as 100 ppn of Di-t-butyl hydroxy toluene (BHT) is added to TAIC® as a stabilizer, it is recommended that it be stored in as cool and dark a place as possible.

As TAIC® might become solidified in winter, it should be stored in a warm room or melted with warm water at a temperature of 35° - 50°C.

In case of removal from TAIC® drums for analyzing, you must warm up the drums with hot water (35° - 50°C) until TAIC® becomes liquid with no crystals present, and stir well before removing.