Siperox® BIBP-42 is a premium bis(tert-butylperoxy isopropyl)benzene (BIBP) peroxide manufactured by Sinocure Chemical Group. With an industry-leading organic peroxide content of 98.80% and active oxygen content of 4.31%, this product delivers exceptional vulcanization efficiency and superior final properties in rubber compounds.
Compared to conventional BIBP grades, Siperox® BIBP-42 provides consistent scorch safety, the highest crosslink density, and faster crosslinking kinetics across all processing temperatures from 155°C to 185°C. It is the ideal choice for manufacturers seeking to upgrade product performance without modifying existing production parameters.
Item | Description |
Product Name | Siperox® BIBP-42 |
CAS Number | 25155-25-3 / 2212-81-9 |
Chemical Name | Bis(tert-butyldioxyisopropyl)benzene; Di(tert-butylperoxyisopropyl)benzene |
Chemical Formula | C₂₀H₃₄O₄ |
Equivalent / Reference Products | Perkadox 14S, Perkadox 14, FARIDA BIPB, Luperox F40, Luperox F90P |
Highest crosslink density (MH-ML) across all tested temperatures (155°C – 185°C)
Outstanding tear strength – over 40% higher than major competitors
Lowest compression set after high-temperature aging (150°C & 175°C)
Excellent thermal aging stability – minimal change in tensile strength and elongation after 72h at 150°C
Uniform scorch time (Tc10) and optimum cure time (Tc90) – enabling drop-in replacement without process adjustments
Highest organic peroxide content (98.80%) ensures maximum efficiency and cost-effectiveness
The microstructure and purity of BIBP directly influence crosslinking performance. Siperox® BIBP-42 distinguishes itself with superior compositional integrity:
Sample | 1,3 BIBP (%) | 1,4 BIBP (%) | BIBP Purity (%) | Mono-peroxide (%) | Alkenyl Peroxide (%) | Organic Peroxide (%) | Active Oxygen (%) |
Supplier A | / | / | 90.34 | 1.80 | 3.82 | 95.96 | 3.98 |
Supplier B | 44.74 | 42.18 | 86.80 | 1.10 | 7.39 | 95.29 | 4.18 |
Supplier D | 49.84 | 44.29 | 94.00 | 0.53 | 3.19 | 97.60 | 4.27 |
Key findings:
Siperox® BIBP-42 has the highest organic peroxide content and highest active oxygen content among all tested products
Supplier A has the lowest active oxygen content, indicating lower crosslinking efficiency
Supplier D shows high BIBP purity but lower organic peroxide content
Rubber compounds based on EPDM (Keltan 6470C, 50 phr N550 carbon black, 20 phr paraffinic oil) were used to compare Siperox® BIBP-42 with three major commercial BIBP competitors.
Peroxide dosage: 5 phr.
Mixing Process: Two-step process — carbon black dispersion in internal mixer, followed by peroxide addition on an open mill.
Sample | Tc10 (min) | Tc50 (min) | Tc90 (min) | ML (dNm) | MH (dNm) | MH-ML (dNm) |
Supplier A | 3.74 | 18.54 | 64.97 | 2.11 | 19.75 | 17.64 |
Supplier B | 3.77 | 18.49 | 64.75 | 2.12 | 19.67 | 17.55 |
Siperox® BIBP-42 | 3.45 | 17.57 | 63.46 | 2.19 | 21.26 | 19.07 |
Supplier D | 3.69 | 18.15 | 64.30 | 2.12 | 20.07 | 17.95 |
At 155°C, the peroxide vulcanization process shows high consistency in terms of scorch safety (Tc10) and optimum cure time (Tc90). The core technical differences lie in the crosslink density (MH-ML). Siperox® BIBP-42 exhibits overall superior crosslinking performance, making it the preferred choice for high-performance vulcanization systems.
Sample | Tc10 (min) | Tc50 (min) | Tc90 (min) | ML (dNm) | MH (dNm) | MH-ML (dNm) |
Supplier A | 1.85 | 8.19 | 28.33 | 2.14 | 20.13 | 17.99 |
Supplier B | 1.75 | 7.92 | 28.11 | 2.16 | 20.44 | 18.28 |
Siperox® BIBP-42 | 1.65 | 7.58 | 27.62 | 2.24 | 22.10 | 19.86 |
Supplier D | 1.70 | 7.74 | 27.85 | 2.15 | 20.85 | 18.70 |
At 165°C, scorch time and optimum cure time remain highly consistent. Siperox® BIBP-42 again delivers the highest torque difference (19.86 dNm), translating directly into a tighter crosslink network and enhanced mechanical strength.
Sample | Tc10 (min) | Tc50 (min) | Tc90 (min) | ML (dNm) | MH (dNm) | MH-ML (dNm) |
Supplier A | 0.81 | 2.84 | 9.59 | 1.88 | 18.94 | 17.06 |
Supplier B | 0.81 | 2.85 | 9.63 | 1.89 | 19.00 | 17.11 |
Siperox® BIBP-42 | 0.76 | 2.68 | 9.34 | 1.95 | 20.71 | 18.76 |
Supplier D | 0.79 | 2.79 | 9.54 | 1.88 | 19.44 | 17.56 |
All peroxides exhibit excellent uniformity in terms of scorch safety and optimum cure time, enabling low-difficulty process control and the adoption of standardized vulcanization parameters. Siperox® BIBP-42 represents the preferred option for high-performance vulcanization systems at 175°C, owing to its superior crosslink density and rapid crosslinking kinetics.
Sample | Tc10 (min) | Tc50 (min) | Tc90 (min) | ML (dNm) | MH (dNm) | MH-ML (dNm) |
Supplier A | 0.52 | 1.41 | 4.45 | 1.95 | 19.79 | 17.84 |
Supplier B | 0.51 | 1.39 | 4.39 | 1.96 | 20.04 | 18.08 |
Siperox® BIBP-42 | 0.49 | 1.36 | 4.40 | 2.02 | 21.74 | 19.72 |
Supplier D | 0.51 | 1.38 | 4.38 | 1.96 | 20.35 | 18.39 |
At 185°C, the overall vulcanization rate is significantly improved compared with lower temperatures, with Tc90 reduced to just 4.3–4.5 minutes — greatly enhancing production efficiency. Tc90 values are highly consistent across all products, allowing the production line to adopt a unified vulcanization process directly. Siperox® BIBP-42 remains the top performer in crosslink density at this elevated temperature.
Shear modulus (G') vs. temperature curves, conducted by Rubber Process Analyzer (RPA), reveal important processing behavior:
The crosslinking initiation temperature of all peroxides falls within 150–170°C, with nearly overlapping curve rebound points. This means peroxide type has no notable impact on initiation temperature — it is jointly determined by the rubber compound system and peroxide decomposition temperature.
In the 170–190°C rapid crosslinking range, Siperox® BIBP-42 shows the steepest modulus rise slope, indicating the fastest crosslinking rate and highest network construction efficiency. This makes it the top choice for high-throughput manufacturing operations.
Mechanical testing on vulcanizates cured at optimal conditions highlights the significant performance edge of Siperox® BIBP-42:
Property | Supplier A | Supplier B | Siperox® BIBP-42 | Supplier D |
Hardness (Shore A) | 63.3 | 63.4 | 64.7 | 65.0 |
Tensile Strength (MPa) | 22.1 | 23.5 | 22.6 | 22.3 |
100% Modulus (MPa) | 2.19 | 2.23 | 2.57 | 2.39 |
300% Modulus (MPa) | 9.75 | 10.17 | 11.58 | 11.22 |
Elongation at Break (%) | 524 | 526 | 484 | 472 |
Tear Strength (Die T, N/mm) | 6.67 | 6.97 | 10.16 | 7.43 |
Compression Set 150°C/70h (%) | 18.9 | 20.0 | 18.8 | 19.1 |
Compression Set 175°C/70h (%) | 21.5 | 21.5 | 19.2 | 20.9 |
The hardness remains essentially consistent, with tensile strength varying only by 5.5%. Siperox® BIBP-42 demonstrates superior tear strength and compression set performance, reflecting a highly efficient and uniform crosslink network.
Critical performance highlights:
Tear strength: 10.16 N/mm — over 40% higher than Suppliers A and B, delivering exceptional resistance to crack propagation in dynamic applications
300% Modulus: 11.58 MPa — indicating a tightly crosslinked network for superior dimensional stability under load
Compression set at 175°C: only 19.2% — ensuring excellent long-term sealing performance at elevated temperatures
After hot-air aging at 150°C for 72 hours, Siperox® BIBP-42 demonstrates best-in-class retention of physical properties:
Property After Aging | Supplier A | Supplier B | Siperox® BIBP-42 | Supplier D |
Tensile Strength (MPa) | 21.3 | 24.0 | 23.1 | 23.2 |
100% Modulus (MPa) | 2.53 | 2.30 | 2.34 | 2.38 |
300% Modulus (MPa) | 10.75 | 9.75 | 10.53 | 10.17 |
Elongation at Break (%) | 471 | 551 | 489 | 525 |
Tear Strength (Die T, N/mm) | 7.87 | 7.83 | 8.58 | 9.33 |
Change Rate After Aging | Supplier A | Supplier B | Siperox® BIBP-42 | Supplier D |
Δ Tensile Strength (%) | -3.6 | +2.1 | +2.2 | +4.0 |
Δ 100% Modulus (%) | +15.5 | +3.1 | -8.9 | -0.4 |
Δ 300% Modulus (%) | +10.3 | -4.1 | -9.1 | -9.4 |
Δ Elongation (%) | -10.1 | +4.8 | +1.0 | +11.2 |
Δ Tear Strength (%) | +18.0 | +12.3 | -15.6 | +25.6 |
After aging at 150°C, Siperox® BIBP-42 tensile strength and elongation at break remain nearly unchanged, achieving the best retention of elasticity among all tested formulations. This indicates that its crosslinking network exhibits excellent thermal stability, effectively resisting post-crosslinking and degradation reactions under high temperatures.
Siperox® BIBP-42 delivers outstanding performance in tensile strength, modulus, and tear strength. Although the change rate of tear strength is slightly negative, its absolute value (8.58 N/mm) is still higher than that of Suppliers A and B — meaning the product remains mechanically superior even after aggressive thermal aging.
For reproducibility and as a starting point for your own evaluations:
Ingredient | phr |
EPDM (Keltan 6470C) | 100 |
Carbon black N550 | 50 |
Paraffinic oil (Sunpar 2280) | 20 |
Antioxidant TMQ | 1 |
Siperox® BIBP-42 | 5 |
Mixing: Two-step process — carbon black dispersion in internal mixer, followed by peroxide addition on an open mill.
Drop-in compatibility: Tc10 and Tc90 align with all major BIBP brands — no need to modify your existing curing cycle
Highest crosslink density without sacrificing scorch safety gives you stronger, more durable rubber parts
Exceptional tear resistance directly improves product reliability in dynamic applications (seals, gaskets, hoses, profiles)
Low compression set maintains sealing force over the lifetime of the part, even at 175°C
Excellent hot-air aging ensures consistent performance after prolonged thermal exposure
Backed by Sinocure Chemical Group — a global supplier with strict quality management and dedicated technical support
Sinocure Chemical Group is a leading developer and manufacturer of organic peroxides, serving the rubber, plastics, and thermoset resin industries worldwide. Our Siperox® range of peroxides represents the culmination of decades of formulation expertise, modern production facilities, and a commitment to delivering consistent, high-purity products that help our customers improve efficiency and final product quality.
Contact us today to request a sample, obtain a detailed technical data sheet, or discuss how Siperox® BIBP-42 can optimize your rubber vulcanization process.
