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N-phenylmaleimide: IMILEX™-P


Product N-phenylmaleimide: IMILEX™-P

Chemical Structure

CAS No. 941-69-5
Formula C10H7NO2
Molecular Weight 173.16
Packing 20kg Paper Bag or 800kg Big Bag
Applications Improving agent for resin heat resistance,Photosensitive resin, Fungicides

IMILEX-P (N-Phenylmaleimide) is first commercialized by Nippon Shokubai with unique production technologies. IMILEX-P is expected for various applications for its reactivity and unique properties such as radical polymerization, ion polymerization, photosensitivity and bacteriostasis.

1.Typical Properties

Item Unit Typical Properties
Appearance -- Yellow Solid
Melting Point C 88 - 90
Boiling Point C 135 (0.48 kPa)
Solubility -- IMILEX-P shows high solubility to organic solvents, especially, to acetone, DMF, acetic acid esters, benzene, etc.
Please refer to Section 6. Solubility of IMILEX-P.


Item Unit Specification
Appearance -- Yellow flake
Melting Point C ≥89
Water content Wt% ≤0.1

3. Copolymerization Reactivity

(Monomer reactivity ratios at copolymerization of IMILEX-P (M1) and other vinyl monomer (M2))

M2 r1 r2 r1×r2
Styrene 0.047 0.012 0.0006
Vinyl chloride 1.260 0.062 0.08
Methylmethacrylate 0.183 1.022 0.19

(Reference) J.Macromol.Sci.,All,267 (1977), Technology Reports of the Yamaguchi University Vol.27.,257 (1977)

4. Package

20kg Paper Bag or 800kg Big Bag

5. Regulatory information

ENCS : 5-5727
TSCA : Listed
SARA Title III 313 : not listed
SNUR : not listed
CEPA : NDSL listed
AICS : listed
EINECS: 213-382-0
CLASSIFICATION etc. : not listed on 67/548/EEC ANNEX I.
ECL : KE-28389
SWISS : not listed
PICCS : Listed

Above information is as of preparation of this website. Please check latest regulatory information at your responsibility before handling IMILEX-P.

6. Solubility of IMILEX-P (Amount of IMILEX-P soluble to 100g of solvent (25 C))

Solvent Solubility (g) Solvent Solubility (g) Solvent Solubility (g)
Acrylonitrile 100 Ethyl acetate 29 o-Xylene 14
DMF 51 Benzene 28 Methanol 9
Acetone 48 Styrene 21 Ethanol 5
THF 44 Toluene 18 Water 0.11
MEK 39 Butyl acetate 18    

7. Typical Applications

• HDT thermoplastic resins • Coatings, adhesives • Intermediate for pharmaceuticals and agricultural chemicals • Bactericides, Fungicides • Vulcanization of rubber • Photosensitive resins • Insulating varnishes

8. Modification of various resins

IMILEX-P readily undergoes homopolymerization and copolymerization with many kinds of vinyl monomers. The polymers copolymerized with IMILEX-P have excellent heat stability and characters.

Example of modification of thermoplastics.

Resin Purpose Application
Styrenic Polymers
(ABS, ACS, AES, AAS etc.)
Improvement of thermal resistance and thermal stability Internal trim parts of automobiles and electronic devices
PVC Improvement of thermal resistance of PVC-ABS Housing for TV and OA machines
PMMA Improvement of thermal resistance Optical disc board, optical fiber, lighting unit
Polymer Alloys Modification of PA, PC, and PBT Automobile parts, householding, electronic devices, OA machines
α-Olefin (Maleic anhydride- N-Phenylmaleimide copolymer)   Adhesives, coating materials, paper additives
Phenolic Resin Improvement of thermal resistance Thermal resistant adhesive for printed-circuit board

Comparison of Modified ABS resins.

  N-Phenylmaleimide-modified ABS α-methylstyrene-modified ABS
Monomer IMILEX-P α-methylstyrene
Copolymerization rate Fast Slow
HDT/wt%-Monomer 1.5-2.5 C ~0.5 C
HDT Upper Limit Over 150 C possible ~115 C
Temperature of decomposition High Low
Melt Flow Rate High Low

Comparison of physical properties of N-Phenylmaleimide (IMILEX-P)-modified ABS resin and α-methylstyrene type ABS at same HDT.

Property Unit N-Phenylmaleimide -modified ABS α-methylstyrene-modified ABS
Heat Deflection Temp. C 105 105
Izod Impact Strength (1/2",notched) kg•cm/cm 18 12
Melt Flow Rate (220 C/10kg load) g/10min 10 6
Tensile Strength kg/cm2 455 440
Flexural Strength kg/cm2 760 720

(reference) NIKKEI NEW MATERIALS, March 9, 1992

Example of copolymerization

Initial composition in reactor Methylethylketone 25.6 wt%
Styrene 6.5 wt%
t-butylperoxyoctate 0.4 wt%
n-Dodecylmercaptan 0.4 wt%
Composition in dropping vessel Methylethylketone 23.6 wt%
IMILEX-P 7.8 wt%
Styrene 35.7 wt%
: 85 C
: 5 hours
: Nitrogen

After the reaction, the reaction mixture is poured into plenty of methanol. Then, the copolymer is separated from the solution by filtration and dried under reduced pressure.

Properties of IMILEX-P/styrene copolymer
: Styrene/N-Phenylmaleimide = 70/30 (Molar ratio)
Molecular weight
: Mw = 10*104 (G.P.C., Polystyrene standard)
  5*104 (G.P.C., Polystyrene standard)
Glass transition temp.
: 165 C (DSC)

Modification of PVC

PVC is blended with ABS resin in order to improve its low impact strength at low temperature, however, the softening temperature of the blend is still low. IMILEX-P is effective for improvement of the softening temperature.

9. Handling and Hazards

(Please refer to Safety Data Sheet (SDS) for detail)


Skin irritation
Mild to moderately irritative
Skin inflames when IMILEX-P is kept contacting with skin
Eye irritation
Moderately irritative
Acute oral toxicity (LD50)
128mg/kg (rat, male), 148mg/kg (rat, female)

Handling and Protection

Read material safety data sheet (MSDS) before handling IMILEX-P. Put on rubber gloves, long sleeve clothing, gas mask for organic gas and protective spectacles to avoid contact with skin, especially contact with eyes when handling IMILEX-P. Take off the clothing which IMILEX-P contacts after handling. If you have any question about handling IMILEX-P, please contact us.

First Aid

Contact with skin: Flush with running water using a mild soap. Contact with eyes: Gently rinse with clean water for at least 15 minutes and call a physician.


Store in a warehouse at temperature lower than 40 C. Avoid sunshine and moisture.

Please read Safety Data Sheet (SDS) before handling.

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