Polybond: Properties, Uses in Plastics and Regulatory Status

POLYBOND is a range of maleic anhydride grafted polyolefins sold by SI Group as coupling agents and reactive compatibilizers for polypropylene and polyethylene compounds, and its polypropylene-grafted grades carry CAS 25722-45-6. Five grades are recorded in our sources: POLYBOND 3200, 3000, 3150 and 3002 on polypropylene, and POLYBOND 3029 on HDPE. Because the product carries two job titles, the first question a formulator asks is which role a grade is bought for.

The regulatory position follows from one fact: POLYBOND is a polymer. Article 2(9) of Regulation (EC) No 1907/2006 (REACH) exempts polymers from registration, its EU food-contact position is set by the monomer maleic anhydride (FCM 234, group restriction 3, SML(T) 30 mg/kg as maleic acid, Regulation (EU) No 10/2011), and no generic 21 CFR listing covers the grafted polypropylene. POLYBOND sits in the compatibilizer and coupling-agent group of our substance directory of plastic additives, which carries the same fields for every substance.

This page holds the brand and the chemistry together: the grade family, the grafting reaction, the interface chemistry, the properties of POLYBOND 3200, dosage per polymer, 5 applications, measured property gains, the regulatory matrix, the monomer hazard record, the alternatives and the sourcing route.

Table T1. POLYBOND identity card.

Footnote: CAS 25722-45-6 describes maleic anhydride grafted polypropylene. POLYBOND 3029 is a maleic anhydride grafted HDPE, so this CAS number does not describe it; no separate identifier for the grafted HDPE is recorded in our sources. Status as of 24 September 2026.

What Is Polybond?#

POLYBOND is SI Group's product line of functionalized polyolefins: polypropylene or polyethylene chains carrying grafted maleic anhydride groups that give a non-polar polymer a reactive, polar handle. On the chain that group exists as a succinic anhydride ring, the reactive site the whole product depends on. SI Group is a specialty chemicals producer based in The Woodlands, Texas, which runs 18 manufacturing sites and joint ventures and lists POLYBOND among its brands ETHANOX, WESTON, ANOX, LOWINOX, NAUGARD and EVERCYCLE. Distributor catalogues file it under the generic label polymer modifier.

What does the POLYBOND name actually cover? It covers a family rather than a molecule: 5 grades on 2 polyolefin backbones, each sold for a different interface. A functionalized polyolefin carries a chemically distinct group attached after polymerization, here maleic anhydride added by a radical reaction. The backbone keeps its compatibility with the matrix resin, so the product disperses into a polyolefin compound while its anhydride groups stay free to react.

Is Polybond a brand name or a chemical?#

POLYBOND is a brand name, not a chemical name: the underlying substance is a maleic anhydride grafted polyolefin, and the polypropylene-grafted version carries CAS 25722-45-6. The generic names in the literature are PP-g-MAH, PP-g-MA, MAPP and maleated polypropylene, and suppliers also label it polymer modifier. A trade name identifies a grade with a specification behind it, while a CAS number identifies the chemistry alone, so a specification that names POLYBOND without a grade number describes nothing a supplier can ship.

Which Polybond grades exist?#

Five POLYBOND grades are recorded in our sources: POLYBOND 3200, POLYBOND 3000, POLYBOND 3150 and POLYBOND 3002 on a polypropylene backbone, and POLYBOND 3029 on an HDPE backbone. The recorded data behind each grade differ sharply.

Table T2. POLYBOND grades and what our sources record for each.

Footnote: the melting point and the melt flow rate published for POLYBOND 3200 are held back pending verification against the current data sheet.

This list covers the grades for which we hold verified data; SI Group's catalogue is larger, and distributor catalogues split the range into a polypropylene-based and a polyethylene-based line.

Is Polybond a compatibilizer or a coupling agent?#

POLYBOND is both: the industry calls a maleated polyolefin a coupling agent when it joins a polymer to an inorganic or natural surface, and a compatibilizer when it joins two immiscible polymers, and SI Group sells POLYBOND 3200 under the first name while formulators use it under the second. What sits on the other side of the interface decides which name is used.

A compatibilizer works on a polymer-polymer interface, lowering interfacial tension, suppressing coalescence of the dispersed droplets and raising interfacial adhesion. Among compatibilizers, the reactive types form a bond across the interface rather than sitting at it, and a grafted anhydride is the classic reactive type.

The 2 roles carry different dose ranges.

A coupling agent works on a polymer-filler interface instead, bonding to a mineral or cellulosic surface while its backbone stays soluble in the matrix. Maleated polyolefins sit beside silanes and titanates on coupling agents for filled and reinforced plastics.

Is Polybond the same as maleic anhydride grafted polypropylene (PP-g-MAH)?#

Yes for the polypropylene grades: POLYBOND 3200, POLYBOND 3000, POLYBOND 3150 and POLYBOND 3002 are maleic anhydride grafted polypropylene, CAS 25722-45-6, the material the literature calls PP-g-MAH or MAPP. POLYBOND 3029 is the exception, grafted onto HDPE rather than polypropylene, and no identifier for that grafted HDPE is recorded in our sources. POLYBOND is one commercial expression of the wider group of maleic anhydride grafted polymers, which also covers PE-g-MAH, POE-g-MAH and SEBS-g-MAH.

Brand and entity are not interchangeable in a specification. The generic entity, maleic anhydride grafted polypropylene (PP-g-MAH), carries the identity data that applies to every brand built on it, while the brand carries the graft level and the melt flow rate that decide how a lot behaves in an extruder.

How Does Polybond Work? Grafted Anhydride at the Interface#

POLYBOND works by anchoring one end of a polyolefin chain chemically to a polar surface: the grafted succinic anhydride groups react or hydrogen-bond with the silanol (Si-OH) groups of glass fibre and the hydroxyl groups of cellulose, and form imide links with the amine end groups of polyamides. On the matrix side the polypropylene backbone co-crystallizes and entangles with the matrix, so stress transfers across the interface instead of stopping at it.

Why does an anhydride group make such a difference in a non-polar compound? Untreated polypropylene has nothing to offer a silanol or a hydroxyl surface, so a filled compound fails by debonding at the particle rather than yielding in the matrix, and the anhydride supplies the missing chemistry at about 1 wt% graft level.

A compatibilizer changes 3 things at the interface, all at once.

• Interfacial tension: it falls, so the dispersed phase breaks up more finely during mixing.
• Coalescence: it is suppressed, so the fine droplets survive the rest of the process instead of merging again.
• Interfacial adhesion: it rises, so stress transfers across the boundary instead of debonding it.

How is Polybond made, and what does grafting do in compounding?#

POLYBOND is made by reactive extrusion: a peroxide initiator abstracts hydrogen from the polypropylene chain, maleic anhydride adds to the macroradicals, and the grafted product leaves the extruder as pellets. Maleic anhydride does not homopolymerize at the 180 to 190 °C (356 to 374 °F) of that process, so the grafts stay short. Molar mass falls as the grafted anhydride content rises towards about 1 wt% and then plateaus, so commercial PP-g-MAH sits at about 0.5 to 1.5 % grafted maleic anhydride and POLYBOND 3200 at 0.8 to 1.2 %.

Beta-scission of the polypropylene competes with the grafting reaction and intensifies with the peroxide level, so the grafted product always has a lower molar mass and a much higher melt flow rate than its feed resin. Reactive extrusion is a plastic compounding operation, not a separate polymerization plant, and the compounder buys the graft level instead of producing it. No peroxide type or dose for the commercial grades is recorded in our sources.

What Are the Physical Properties and Melt Flow Rate of Polybond?#

POLYBOND 3200 is supplied as off-white pellets with a density of 0.91 g/cm3 at 23 °C (73.4 °F), a bulk density of 0.6 g/cm3 and a grafted maleic anhydride content of 0.8 to 1.2 %. Those 4 values are the complete recorded set for the grade.

Table T3. Recorded physical properties of POLYBOND 3200.

Footnote: no grade-specific property data for POLYBOND 3000, POLYBOND 3150, POLYBOND 3002 or POLYBOND 3029 are recorded in our sources. Status as of 24 September 2026.

Our sources also carry a melting point and a melt flow rate for POLYBOND 3200, but the supplier data sheet was unreachable when those values were checked on 22 September 2026, so this page does not publish them until they are confirmed. A second reason to check is the test condition: melt flow rate (MFR / MFI / MVR) for a polypropylene-based product is normally reported at 230 °C (446 °F) and 2.16 kg under ISO 1133-1 and ASTM D1238, while the listing we hold quotes 190 °C (374 °F).

Which Polymers Use Polybond, and at What Dosage?#

POLYBOND is used almost entirely in polyolefin compounds: filled and glass-reinforced polypropylene at roughly 1 to 5 wt%, and recycled polypropylene blended with nylon at about 5 wt%. Published studies of polypropylene with short glass fibre test maleated polypropylene at 0.5 to 2 wt% of the compound, and the trade-press survey that records POLYBOND by grade names 5 % in recycled PP with nylon.

Table T4. Recorded POLYBOND and MAPP dosage per polymer system.

Is a coupling agent dosed on the compound or on the filler? On the total compound in every study above, because a level quoted on the filler alone describes a different quantity. Compounders who work in PHR (parts per hundred resin) convert a weight percent with the full formulation total, not with the resin alone: wt% = phr of the ingredient divided by total phr, multiplied by 100. The class ranges are roughly 1 to 5 wt% as a coupling agent and 2 to 10 wt% as a compatibilizer, and no dosage figure exists in our sources for POLYBOND 3000 or POLYBOND 3029.

Polybond in glass-fibre, talc- and mica-filled polypropylene#

Glass-filled polypropylene is the application SI Group markets POLYBOND 3200 for, describing it as a high-efficiency coupling agent for glass-filled PP. The same grade is recorded for mica-, talc-, wood- and natural-fibre-filled polypropylene. In published studies of PP with short glass fibre, maleated polypropylene is tested at 0.5 to 2 wt% of the compound, and tensile, flexural and impact properties rise with the level. The selection logic sits on coupling agents for glass- and talc-filled polypropylene.

The glass surface is not bare when the coupling agent meets it. Glass fibre carries a sizing applied at the bushing that contains 0.5 to 2.0 wt% of a silane, and aminosilane sizings are the standard for polyamide and polypropylene, which is the surface the grafted anhydride reacts with. Talc and mica arrive untreated or treated with a different chemistry, so the anhydride works on the hydroxyl groups at the mineral edge.

Coupling is one decision inside a filled polypropylene recipe. A glass-filled automotive compound also carries an antioxidant package, a lubricant and often a nucleating agent, all described under additives for polypropylene (PP).

Polybond in recycled polypropylene and nylon#

Recycled polypropylene contaminated with nylon is the clearest documented POLYBOND case: at 5 %, POLYBOND 3150 and POLYBOND 3002 raised notched and reverse Izod impact strength about threefold in the Plastics Technology compatibilizer survey. That figure comes from a survey of supplier data rather than a peer-reviewed trial, and it is the only property figure in our sources carrying a POLYBOND grade name. Dosage ranges for every polymer pair in recyclate are tabulated on compatibilizers for recycled plastics.

The chemistry behind the recovery is the imide link. Polyamide chains end in amine groups, the grafted anhydride reacts with them during melt mixing, and the copolymer formed sits at the phase boundary and holds it together under impact. Reactive compatibilization of PA with PP is the industrial standard for exactly this reason: a physical blend separates, a reacted blend transfers load.

Compatibilizers persist in the material and become legacy additives in the next recycling stream, as Scholz and colleagues reported in 2026. The amine end groups that make this reaction work are a property of the polyamide itself; see additives for nylon (polyamide).

Polybond in wood-plastic composites#

In wood-plastic composites, POLYBOND couples hydrophilic wood flour to the polyolefin matrix, which lowers water uptake and raises flexural and tensile strength. POLYBOND 3200 and the FUSABOND E-series are the 2 products our sources name for that job. The anhydride reacts with the cellulose hydroxyl groups at the wood surface, and the bonded interface keeps water out of the fibre. Loading levels for wood flour and natural fibre are compared on coupling agents for wood-plastic and natural fibre composites.

Dose optimisation is property-dependent: in a 2026 study of a glass-fibre-reinforced wood and polypropylene composite published in Materials, the optimum maleated polypropylene level was 1 wt% for flexural strength, which rose 24.7 %, and 3 wt% for tensile strength, modulus and impact. Temperature sets the outer limit, because cellulose degrades above the wood-plastic matrix maximum of about 200 °C (392 °F), and WPC compounds run about 28 °C (50 °F) below the unfilled resin. The coupling agent works alongside lubricants, UV stabilizers and biocides in the package described under additives for wood-plastic composites (WPC).

What Is Polybond Used For? 5 Applications in Filled, Reinforced and Recycled Plastics#

POLYBOND is used in 5 recorded application areas: glass-fibre polypropylene automotive parts, talc-filled polypropylene, wood-plastic composite decking, PP/PA alloys and the upgrading of recycled polypropylene. The 5 are described below.

• Glass-fibre PP automotive parts: polypropylene reinforced with short glass fibre, where the coupling agent converts fibre length into stiffness.
• Talc-filled PP: mineral-filled interior and appliance compounds, where the anhydride bonds to the mineral edge.
• WPC decking: wood flour in polyethylene or polypropylene, where coupling lowers water uptake and raises flexural strength.
• PP/PA alloys: blends of polypropylene with polyamide, where the anhydride and the amine end groups react across the phase boundary.
• Recycled PP upgrading: post-consumer polypropylene carrying nylon contamination, where a compatibilizer restores impact strength.

Automotive parts made from glass fiber reinforced plastics are the largest recorded POLYBOND application, and the 5 share one pattern: a non-polar polyolefin against a polar surface or polymer. Applications recorded for other maleated polyolefin brands, such as halogen-free flame-retardant cable compounds, are not claimed here.

How Much Does Polybond Improve Tensile, Flexural and Impact Strength?#

The measured gains depend entirely on the system: in one hybrid cellulose and basalt fibre polypropylene composite, 5 wt% of maleic anhydride grafted PP raised tensile strength by 45 %, flexural strength by 97 % and notched Charpy impact strength by 13 % against neat polypropylene. Each percentage compares with the unmodified reference of that study, never with compounds in general.

The test method decides what a number means. Tensile strength is measured under ISO 527-1 and ISO 527-2 or ASTM D638-22, notched Izod under ASTM D256-26 (J/m) or ISO 180 (kJ/m2, specimen 63.5 x 12.7 x 3.2 mm) and notched Charpy under ISO 179 (kJ/m2). Every percentage here compares two compounds measured the same way; see tensile testing of plastics.

Table T5. Recorded property effects, with test methods and source type.

The optimum is property-dependent rather than a single number, so a formulator runs a ladder of 3 to 4 levels rather than a single trial. Notched Izod and notched Charpy are different tests with different units, which is set out on impact strength (Izod, Charpy), so a value in J/m and a value in kJ/m2 never compare directly. Apart from the recycled PP and nylon Izod figure, every value above was measured on generic MAPP or MA-g-PP rather than on a POLYBOND grade.

How Does Polybond Interact with Other Additives?#

POLYBOND does not act alone at the interface: on glass fibre it works on top of the aminosilane sizing applied at the bushing, and on mineral fillers it competes with the stearic-acid coating or the titanate treatment the filler supplier has used. Three interactions decide whether the coupling agent pays for itself.

• Fibre and filler surface treatment: a silane sizing at 0.5 to 2.0 wt% on the fibre presents reactive groups and helps, while a stearic-acid coating occupies the same surface and can block the anhydride.
• Stabilizer package in recyclate: a compatibilizer restores impact strength and an antioxidant restores processing stability, so restabilization pairs the two.
• Next recycling loop: the compatibilizer stays in the material and becomes a legacy additive in the following stream, as Scholz and colleagues reported in 2026.

Surface chemistry explains why filler suppliers do not silane-treat everything: silanes are excellent on silica, quartz and glass and poor on calcium carbonate, gypsum, barytes, graphite and carbon black, where titanates or stearic acid replace them. That split is a property of the silane chemistry, not a limitation of maleated polyolefins. A compatibilizer and an antioxidant fix different failures, the general rule described under additive interactions, so both lines stay in a recyclate recipe.

What Is the Regulatory Status of Polybond?#

POLYBOND is a polymer, so it carries no REACH registration number of its own (Article 2(9) exempts polymers, while their monomers are registered separately), and its EU food-contact position is set by its monomers rather than by the grafted polymer itself (status 24 September 2026).

Table T6. POLYBOND regulatory matrix, as of 24 September 2026.

Recycled-content law is what turns this class into a growth market; the targets are set out under the EU Packaging and Packaging Waste Regulation (PPWR), Regulation (EU) 2025/40, which applies from 12 August 2026 and sets minimum post-consumer recycled content in plastic packaging from 1 January 2030.

Is Polybond registered under REACH?#

No, and it does not need to be: Article 2(9) of Regulation (EC) No 1907/2006 exempts polymers from registration, so a grafted polyolefin such as POLYBOND has no registration number, while the monomers it is built from are registered separately. The exemption covers registration, not regulation: the polymer still falls under classification and labelling obligations and under food-contact law through its monomers, while no restriction names this additive group. Substance of Very High Concern status is not applicable to a polymer, and maleic anhydride is not on the Candidate List. The polymer exemption and what it does and does not cover are explained on REACH and plastic additives.

Is Polybond allowed in food-contact plastics?#

In the EU the question is answered at the monomer level: maleic anhydride is listed in Annex I of Regulation (EU) No 10/2011 as FCM substance 234 under group restriction 3, with a total specific migration limit of 30 mg/kg expressed as maleic acid. Propylene, the other monomer of the polypropylene grades, is FCM 275 with no specific migration limit. A group restriction means the 30 mg/kg ceiling is shared with the other substances in group 3, so a compound containing more than one of them splits a single limit. Group restrictions and the way a monomer limit reaches a finished article are explained on EU 10/2011.

In the United States there is no generic 21 CFR listing for maleic anhydride grafted polypropylene. The closest listings cover different chemistries, ethylene-maleic anhydride copolymers at up to 2 % MAH under 21 CFR 177.1520 and maleic-anhydride-grafted EVA under 21 CFR 177.1350. The absence of a listing is not a prohibition, and a grade-specific US position comes from the supplier in writing.

What is the US status of Polybond under the FDA, TSCA and Proposition 65?#

The United States position on POLYBOND is incomplete in the public record: no generic 21 CFR listing covers maleic anhydride grafted polypropylene, and our sources record no TSCA or Proposition 65 entry for the grafted polymer.

The FDA route for a material without a generic listing runs through a food contact notification or a supplier declaration for the grade, which is why this page prints "being verified" rather than a status. How a US clearance is established when no listing exists is set out on FDA food contact rules for plastic additives (21 CFR). The phrase "FDA approved" applies to no plastic additive and appears nowhere on this page.

TSCA inventory status and California Proposition 65 status for CAS 25722-45-6 are both empty fields in our source library and are being verified. Absence from a Proposition 65 listing is itself a publishable answer once that check is complete.

Is Polybond Safe? Health, Safety and Handling#

Our sources record no hazard classification for the grafted polymer itself, but they do record a harmonised classification for its monomer: maleic anhydride is a respiratory sensitiser (H334) and a skin sensitiser (H317), corrosive to skin (H314) and seriously damaging to eyes (H318). That distinction matters in practice, because a grafted pellet is not a drum of monomer: the compounder's question is the residual maleic anhydride content of the grade, which the supplier states in its safety data sheet.

The 2 hazard positions to keep apart are set out below.

• The polymer: pellets, not a registered substance under REACH, and no classification in our sources.
• The monomer: maleic anhydride carries the harmonised CLP classification Acute Tox. 4 H302, Skin Corr. 1B H314, Eye Dam. 1 H318, Resp. Sens. 1 H334, Skin Sens. 1A H317 and STOT RE 1 H372 (index 607-096-00-9, ATP13), and the sensitisation entries are harmonised, not proposed.

Handling follows the rules for a reactive pellet, not those for a corrosive liquid: anhydride groups hydrolyse to the diacid on contact with moisture, so dry storage and the residual monomer statement are the practical questions. No LD50, occupational exposure limit or residual-monomer level for a POLYBOND grade is recorded in our sources, and this page makes no claim that any grade is monomer-free.

What Are the Alternatives to Polybond?#

The recorded alternatives to POLYBOND fall into 2 groups: other maleated polyolefin brands, led by Dow's FUSABOND and SK Functional Polymer's OREVAC, and different coupling chemistries such as acrylic-acid-grafted PP, glycidyl-methacrylate-grafted PP and silane sizing used on its own. Table T7 sets out what our sources verify for each.

Table T7. POLYBOND and its recorded alternatives.

Polybond vs Fusabond#

POLYBOND and FUSABOND are competing lines of the same chemistry: both are maleic anhydride grafted polyolefins, and both are sold as coupling agents, compatibilizers and tie resins, so the choice is made on grade fit, not on chemistry. The recorded difference is breadth of backbone: our sources list POLYBOND with 4 polypropylene grades and 1 HDPE grade, while FUSABOND is recorded with polyethylene, polyethylene-copolymer and polypropylene series, including FUSABOND E226 on LLDPE and FUSABOND E205 and E204 on HDPE. In a polypropylene compound the POLYBOND 3xxx grades and the FUSABOND P-series, for example P613 and P353, occupy the same slot.

Two recorded uses show the overlap and the divergence. Both POLYBOND 3200 and the FUSABOND E-series are named for wood-plastic composites. FUSABOND E226 appears at 8 phr in a halogen-free flame-retardant cable reference formulation alongside a Lotader terpolymer at 8 phr, in an EVA 67 / LLDPE 17 / ATH 160 compound, an application our sources do not record for POLYBOND. No head-to-head test of the 2 brands exists in our sources, so this page names no winner; Fusabond carries the grade-by-grade detail of the competing line.

Orevac, Exxelor and other Polybond trade-name equivalents#

Maleated polyolefins are sold under at least 7 other trade names: OREVAC from SK Functional Polymer, Exxelor from ExxonMobil, ADMER from Mitsui, Scona from BYK, Bondyram from Polyram and the Chinese lines Coace and Baoxu. OREVAC reached SK Functional Polymer with Arkema's functional polyolefin business in 2020, together with the Lotader, Lotryl and Evatane lines, although our check could not confirm the current OREVAC polypropylene grade list, nor ExxonMobil's current status as a supplier under the Exxelor name.

Brand-to-chemistry mappings for the whole additive market sit in the plastic additive trade name lookup. No grade-for-grade equivalence is established in our sources, so this page publishes no equivalence table: a grade that replaces POLYBOND 3200 is requalified on graft level, melt flow rate and finished-compound properties, not on a name.

Silane coupling agents on the glass fibre as an alternative#

The alternative to adding a coupling agent to the compound is to rely on the sizing already on the fibre: glass fibre carries 0.5 to 2.0 wt% of a silane, applied at the bushing together with a film former. In a polypropylene matrix that sizing has nothing to bond to chemically, which is why a maleated polyolefin is added to the compound as well. In a polyamide or epoxy matrix the aminosilane reacts with the matrix directly, and the second additive becomes unnecessary.

Substrate decides the chemistry: the silane-only route is open for a glass-reinforced compound and closed for a chalk-filled one, because silanes are ineffective on calcium carbonate. What a sizing can and cannot do on its own is covered under silane coupling agents.

Who Makes Polybond? SI Group Grades, Suppliers and Sourcing#

POLYBOND is made by SI Group, a specialty chemicals producer based in The Woodlands, Texas, with 18 manufacturing sites and joint ventures, which sells it alongside its ETHANOX, WESTON, ANOX, LOWINOX, NAUGARD and EVERCYCLE brands. The recapitalization of SI Group closed on 23 December 2025, and the brand list and site footprint are in the profile Si Group: plastic additives portfolio. Distributors publish much of the grade documentation; our sources name none of them as authorised or exclusive.

Table T8. Sourcing POLYBOND: what you need and where our sources place it.

We publish no price for POLYBOND: no sourced price figure for maleated polyolefins exists in our source library, and quoting a distributor list price as a market price would be misleading. Prices for this class move with polypropylene and maleic anhydride feedstock costs and with the order quantity. Buyers should ask the supplier for the current technical data sheet, the safety data sheet with the residual maleic anhydride statement, and a written food-contact statement for the grade. Equivalent producers are listed in the directory of compatibilizer and coupling agent suppliers.

How Do Maleated Polyolefins Fit into the Compatibilizer Family?#

POLYBOND is one brand inside the maleated polyolefin class, the group that sits across 2 additive families at once: compatibilizers, which join two immiscible polymers, and coupling agents, which join a polymer to an inorganic or natural surface. European sources spell the first family compatibilisers, and three interfacial effects define it either way: lower interfacial tension, suppressed coalescence and higher interfacial adhesion. The class covers PP-g-MAH, PE-g-MAH, POE-g-MAH and SEBS-g-MAH, which differ only in backbone. An anhydride-grafted elastomer is sold both as a compatibilizer and among the impact modifiers, which is where the two families overlap.

Polybond and the shift to recycled polyolefins#

Recycled-content law is the reason compatibilizer demand is growing: the EU Packaging and Packaging Waste Regulation (EU) 2025/40 applies from 12 August 2026 and sets minimum post-consumer recycled content from 1 January 2030. The 2030 minima are 30 % for contact-sensitive PET packaging, 30 % for single-use plastic beverage bottles, 10 % for other contact-sensitive plastic packaging and 35 % for other plastic packaging, rising in 2040 to 50 %, 65 %, 25 % and 65 %. Mixed post-consumer polyolefin streams carry the contamination that makes those targets hard to reach; the full formulation answer is on additives for recycled plastics.

Food contact adds a second rulebook. Recycled plastics intended for food contact fall under Regulation (EU) 2022/1616, which governs the recycling processes rather than the additives in them, and is summarised under recycled plastics regulations.

The trade-off is what happens on the next loop: the additive that rescues one recyclate persists and becomes a legacy additive in the following stream, as Scholz and colleagues reported in 2026. That is the trade-off examined under design for recycling.

Other products sold under the Polybond name#

The Polybond name is used by unrelated businesses in other industries: a construction base coat, a polyurethane mould-repair adhesive, a roofing membrane and two companies that carry the word in their corporate name. None of them is a plastics additive, and none is covered on this site. This page covers only the SI Group coupling agents and compatibilizers built on maleic anhydride grafted polyolefins, CAS 25722-45-6 for the polypropylene-grafted grades.

Is the Polybond coupling agent related to Polybond stucco or Polybond adhesive?#

No: the POLYBOND coupling agents described on this page are SI Group's grafted polyolefins for plastics compounding, and they have no connection to the construction or adhesive products that share the name.

Where do I find the Polybond TDS and SDS?#

The technical and safety data sheets come from SI Group or from its distributors, and the safety data sheet states the residual maleic anhydride content of a grade. The producer page was unreachable during our September 2026 check, which is why 2 property values here are held back.

Has Polybond always been an SI Group brand?#

POLYBOND is an SI Group brand today; catalogues filing it under an earlier owner are out of date, and we do not publish the ownership chain because our check could not confirm it.

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