N,N '-m-phenylene bismaleimide HA-8 Ⅰ. Introduction Product name: N,N '-m-phenylene bismaleimide Abbreviation: HA-8/PDM/HVA-2 Molecular formula: C14H8N2O4           Molecular weight: 268 Physicochemical properties: Yellow or brown-yellow powder, specific gravity 1.44, soluble in dioxycontinental ring, tetrahydrofuran and hot acetone, insoluble in petroleum bond, methylene chloride, carbon tetrachloride, benzene and water. CAS NO: 3006-93-7 Appearance: Structure type:     Ⅱ.Technical indicators Items Refers to the standard Appearance Yellow powder Melting point, ℃ 195℃or higher Burning residue, % 0.5% or less Heat reduction, % 0.5% or less Acid value, % 0.9% or less Sieve residue, 325 mesh 0.5% or less   Ⅲ. Use N,N '-m-phenylene bismaleimide manufactured by Yangchen Tech (also known as PDM or HVA-2) is a multifunctional rubber additive used as a vulcanizing agent in rubber processing, as a secondary vulcanizing agent in peroxide systems, and as an anti-curl agent and casting agent. It can be used in general rubber as well as specialty rubber and plastic systems. In natural rubber adhesive, combining with sulfur can prevent the return of moisture from vulcanization, improve heat resistance, reduce heat generation, aging resistance, improve the adhesion between rubber and cord and the modulus of vulcanized rubber. Used in shoulder rubber, cushion layer and other rubber materials, it can solve the shoulder hollow problem of bias truck tires, also can be used in large-size thick products of natural rubber and various rubber miscellaneous products. As an auxiliary vulcanizing agent in special rubbers such as chloroprene rubber, chlorosulphonated polyethylene rubber, styrene butadiene rubber, nitrile rubber, isoprene rubber, butyl rubber, bromobutyl rubber, acrylate rubber, silicone rubber and elastomer rubber, it can significantly improve cross-linking performance, improve heat resistance, suitable for high temperature vulcanization system, and reduce the compression permanent deformation is very obvious. It also reduces the amount of peroxide, prevents the rubber from burning during processing, and improves the adhesive strength between the rubber and the cord and metal. PDM is a sulfur-free vulcanizing agent, used for cable rubber, it can replace thiazoles, thiuram class and other sulfur-containing vulcanizing agents, to solve the copper wire and copper electrical appliances due to contact with sulfur-containing vulcanizing agent copper sulfide pollution black problem.        PDM is a sulfur-free vulcanizing agent for cable rubber, which can replace sulfur-containing vulcanizing agents such as thiazole and thiuram to solve the problem of blackening of copper wire and copper electrical appliance due to sulfur-containing agents and copper sulfide contamination.   If you have any questions,pls feel free to contact: business@xysjgm.com      

N,N'-m-Phenylene bismaleimide has a variety of applications in tire manufacturing. This chemical can be used as a multifunctional rubber additive, either as a vulcanizing agent or as a co-curing agent in peroxide systems. In addition, it can be used as an anti-scorch agent and viscosity builder.   In natural rubber, N,N'-m-Phenylene bismaleimide, when used in combination with sulfur, prevents vulcanization regression, improves heat resistance, reduces heat generation, enhances aging resistance, and improves the adhesion between the rubber and the cord as well as the modulus of the vulcanized rubber. Therefore, it has a wide range of applications in rubber products such as shoulder rubber and cushion layer of heavy-duty tires, which helps to solve the problem of shoulder void in bias-loaded tires. At the same time, this additive is also suitable for large-size thick products of natural rubber and various rubber miscellaneous products.   In special rubber such as chloroprene rubber, chlorosulfonated polyethylene rubber, styrene butadiene rubber, nitrile rubber, isoprene rubber, butyl rubber, bromobutyl rubber, acrylate rubber, silicone rubber and rubber-plastic concurrently with rubber, N, N'-m-phenylene bismaleimide as an auxiliary vulcanizing agent, can significantly improve the performance of crosslinking, improve heat resistance, especially suitable for high-temperature vulcanization system. It can also significantly reduce the compression permanent deformation, reduce the amount of peroxide, to prevent the rubber in the process of scorching, and improve the rubber and cord and metal bonding strength.   The specific dosage of N,N'- m-phenylene bismaleimide will vary depending on the application. For example, when used as an anti-scorch agent, the dosage is usually in the range of 0.5-1.0 parts, when used as a vulcanizing agent, the dosage is 2-3 parts, when used to improve compression set, the dosage is 1.5 parts, and when used to improve bond strength, the dosage is in the range of 0.5-5.0 parts.   Overall, N,N'- m-phenylene bismaleimide plays an important role in tire manufacturing and offers the possibility of manufacturing better quality and more durable tires by improving the properties and processing of rubber.   If you have any questions,pls feel free to contact: business@xysjgm.com

HVA-2 Application in Rubber Tire: The Ultimate Solution for Reversion and Shoulder Separation -By Yangchen Advanced Materials – A Leading HVA-2 Manufacturer   If you are a tire compounder or a rubber technologist, you have probably faced two persistent nightmares:  reversion and shoulder separation. These issues not only reduce tire life but also increase warranty claims and damage brand reputation.   HVA-2 (N,N’-m-Phenylene bismaleimide) – also known as PDM or HA-8 – is a multifunctional rubber additive that effectively eliminates these problems. In this article, we will explore the HVA-2 application in rubber tire manufacturing, backed by real performance data, and explain why Yangchentech is your most reliable supply partner. 1.What is HVA-2? HVA-2 is an aromatic bismaleimide with two reactive double bonds. It acts as: Anti-reversion agent in sulfur-cured natural rubber Co-agent in peroxide systems Adhesion promoter between rubber and cords Heat-resistant modifier for thick rubber articles Its chemical structure allows it to form thermally stable carbon-carbon crosslinks, which do not break down under prolonged high-temperature vulcanization.   2.Why Does the Tire Industry Need HVA-2? Modern tire manufacturing demands higher productivity (shorter cure times) and larger, heavier loads (more heat generation). Conventional sulfur vulcanization produces polysulfidic bonds that are stable only within a narrow temperature window. Once the temperature exceeds 150°C for extended periods (typical in thick tire components), reversion occurs: crosslinks break, network density drops, and mechanical properties collapse. Consequences of reversion in tires: Reduced tread stiffness and tear strength Shoulder separation – a common failure mode in bias truck tires Poor belt edge adhesion Lower retention of dynamic properties   HVA-2 solves this by generating hybrid crosslinks that resist thermal cleavage, maintaining torque even after 30 minutes at 170°C.     3.Key Benefits of HVA-2 Application in Rubber Tire Eliminates Reversion – Proven by Data Testing Condition Conventional Sulfur Cure Sulfur + 2.5 phr HVA-2 Torque retention after 170°C×30 min 85–88% 98–100% Tensile strength retention (100°C×72h) 72–78% 90–95% Modulus at 300% (MPa) Baseline +15%   With HVA-2, your tire compound stays robust even under severe overcure conditions.   Prevents Shoulder Separation in Bias Truck Tires Adding 2–3 phr of HVA-2 to the shoulder pad and breaker compounds significantly improves the adhesion between natural rubber and nylon/polyester cords. The maleimide ring reacts with amino groups on the fiber surface, forming a covalent bond that withstands dynamic flexing and heat aging.   Result: Reduced scrap rates and fewer field failures.   Improves Heat Aging Resistance HVA-2’s hybrid crosslinks do not revert, so the rubber retains its mechanical integrity after prolonged heat exposure. This translates into longer tire life for long-haul trucks and OTR vehicles.   Enhances Processing Safety At low dosages (0.5–1.0 phr), HVA-2 acts as a scorch retarder, delaying Mooney scorch time by 15–20% without affecting cure rate. This gives you a wider processing window, especially during hot summer shop-floor conditions.

In tire manufacturing and industrial rubber goods, the adhesion strength between rubber and tire cord — whether polyester, nylon, or rayon — is a critical determinant of product safety, durability, and service life. Tire cords serve as the reinforcing skeleton, providing strength and resistance to deformation. The adhesion interface between rubber and cord, however, is often the weakest link under demanding conditions such as dynamic loading and high-temperature aging. Traditional adhesion systems rely heavily on "resorcinol-formaldehyde-silica" (RF) systems or RFL dipping processes, which achieve bonding through physical adsorption or limited chemical coupling. Under high-temperature vulcanization, prolonged aging, or dynamic stress, these systems frequently suffer from rapid adhesion decay, leading to quality issues such as shoulder separation and delamination in tires.   HA-8 (N,N'-m-phenylene dimaleimide, also known as PDM or HVA-2) offers a reliable technical solution to these rubber-to-cord adhesion challenges. 1. Mechanism of Action: From Physical Adsorption to Chemical Bonding HA-8 (chemical name: N,N'-m-phenylene bismaleimide, CAS: 3006-93-7) features two highly reactive maleimide groups in its molecular structure. This unique dual-functional structure endows HA-8 with multiple roles in rubber processing: it can function as a vulcanizing agent, a co-vulcanizing agent in peroxide systems, a scorch retarder, and a tackifier. At the rubber-to-cord adhesion interface, HA-8 acts as a "molecular bridge." One maleimide group reacts with rubber molecular chains through cross-linking, while the other reacts with polar groups on the cord fiber surface, forming strong chemical bonds. This molecular bridge mechanism transforms rubber-to-cord bonding from physical adsorption into durable chemical bonding, fundamentally enhancing the stability and longevity of the adhesion interface. In natural rubber, HA-8 combined with sulfur prevents reversion, improves heat resistance, reduces heat generation, and enhances both adhesion to tire cord and vulcanized rubber modulus. 2. Key Applications in Tires and Rubber Products 2.1 Tire Shoulder Compounds and Breaker Layers In tire shoulder compounds and breaker layers, adhesion between rubber and cord directly impacts resistance to shoulder separation. The addition of HA-8 significantly improves adhesion strength between compound and tire cord, effectively addressing shoulder separation issues in bias-ply truck tires. Industry studies confirm that HA-8 applied in shoulder compounds and breaker layers eliminates reversion during high-temperature vulcanization, maintaining stable adhesion interfaces throughout long-term service. 2.2 Tire Ply and Belt Layers In tire ply and belt layers, rubber-to-cord adhesion with polyester, nylon, and other cords is a key factor determining overall tire performance. HA-8 enhances the adhesive strength between rubber, tire cord, and metal, while improving vulcanized rubber modulus — ensuring structural integrity under high-speed and heavy-load conditions. 2.3 Large-Scale Natural Rubber Thick Products For large-scale natural rubber thick products (such as large rubber rollers and engineering rubber goods), uneven vulcanization between interior and exterior during curing is a common challenge. HA-8 application prevents scorch during processing while improving overall adhesion performance in thick-section products. 2.4 Specialty Rubbers and Rubber-Plastic Blends HA-8 is not limited to natural rubber. In specialty rubbers — including CR, CSM, SBR, NBR, IIR, BIIR, ACM, VMQ, and rubber-plastic blend systems — HA-8 serves as an auxiliary vulcanizer that significantly improves crosslinking performance, enhances heat resistance, reduces compression set, and increases adhesion strength. 3. Recommended Dosages HA-8 dosage should be adjusted based on specific application requirements:     Application Purpose Recommended Dosage (phr) As scorch retarder 0.5 – 1.0 As vulcanizing agent 2 – 3 To improve compression set 1.5 To enhance rubber-to-cord adhesion 0.5 – 5.0 For applications demanding high adhesion strength (such as tire shoulder compounds and breaker layers), dosages of 3–5 phr are recommended to achieve optimal bonding performance. 4. Key Advantages of HA-8 Compared to traditional adhesion systems, HA-8 offers the following distinct advantages in rubber-to-cord adhesion applications:     Performance Dimension HA-8 System Traditional Systems Adhesion mechanism Chemical bonding (molecular bridge) Primarily physical adsorption Reversion resistance Effectively inhibited Prone to reversion Heat aging resistance Excellent Rapid decline at high temperatures Compression set Significantly reduced Higher deformation Applicable polymers General + specialty rubbers + blends Limited applicability Processing safety Scorch-resistant, wide processing window Prone to scorch Additionally, HA-8 is a sulfur-free vulcanizing agent suitable for cable rubber applications, where it can replace sulfur-containing systems to eliminate copper sulfide contamination and blackening of copper conductors. Rubber-to-cord adhesion strength is one of the most critical factors determining tire and rubber product quality and service life. HA-8 (N,N'-m-phenylene bismaleimide/PDM/HVA-2), with its unique bismaleimide dual-functional structure, establishes a robust "molecular bridge" at the rubber-to-cord interface — transforming physical adsorption into durable chemical bonding and fundamentally resolving adhesion failures under high-temperature and dynamic conditions. Whether in tire shoulder compounds and breaker layers for truck tires, or in specialty rubber and rubber-plastic blend systems, HA-8 consistently demonstrates exceptional adhesion-promoting effects and comprehensive performance improvements. For formulation engineers seeking high-performance adhesion solutions, HA-8 is undoubtedly a key additive worthy of in-depth evaluation and application. Shaanxi Yangchen New Material Technology Co., Ltd. (www.yangchentech.com) is a professional manufacturer of high-quality HA-8 (N,N'-m-phenylene bismaleimide/PDM/HVA-2). For technical data sheets and sample inquiries, please contact us today.