Shandong Jusage SBS 1401 is a linear styrene-butadiene-styrene block copolymer supplied as porous pellets or crumb. The grade designation 1401 follows the Chinese SBS nomenclature in which the first two digits represent the nominal styrene monomer content; accordingly, the product contains a nominal 40 wt% styrene and 60 wt% butadiene. The polymer derives its physical crosslink network from phase separation of glassy polystyrene end-blocks with a glass transition temperature near 95 °C inside a continuous polybutadiene phase having a glass transition temperature near -80 °C. Because the network is physical rather than sulfur-cured, the material can be melt-processed and solution-processed while recovering elastomeric properties on cooling. The chemical structure is identified by CAS registry number 9003-55-8. End-article regulatory reviews should verify compliance with REACH Annex XVII and RoHS Directive 2011/65/EU when the product is used in electrical or electronic applications.

The values in Table 1 are representative ranges extracted from published datasheets for linear SBS 1401 grades, not lot-specific release limits from Shandong Jusage. Incoming-inspection programs should compare the actual certificate of analysis against the applicable limits, with particular attention to volatile matter and melt flow rate, because these parameters influence extrusion foaming and bitumen dispersion respectively.

What Processing Boundaries Appear When 1401 Is Dispersed in Bitumen?

In polymer-modified bitumen, Shandong Jusage SBS 1401 is metered at 3–6 wt% of the bitumen mass. The base bitumen is heated to 170–180 °C before polymer addition, and dispersion is performed with a rotor-stator high-shear mill. Equipment operating data from continuous PMB units using rotor tip speeds of 15–20 m/s indicate that reduction of the SBS phase to a particle size below 10 μm usually requires 40–60 min. The practical processing window is ±5 °C around a 175 °C setpoint. Above 190 °C, the unsaturated butadiene midblock undergoes thermal oxidative scission, and the finished binder loses low-temperature elastic recovery. Below 165 °C, the polystyrene domains remain insufficiently softened, and the mixer torque rises toward the overload setpoint.

Standard PMB characterization includes softening point by ASTM D36/D36M-14, penetration by ASTM D5/D5M-20, elastic recovery by ASTM D6084-21, and storage stability by ASTM D7173. At 4 wt% 1401 loading, the ring-and-ball softening point of a 50/70 penetration grade bitumen meeting EN 12591 typically shifts from 45–50 °C to 65–75 °C. The exact shift depends on the maltene and asphaltene balance. Bitumens with asphaltene contents above 15 wt% can under-swell the SBS network and produce lower elastic recovery unless the polymer dose is increased or a compatibilizing process oil is added. If sulfur vulcanization is used to stabilize the PMB, addition is held at 0.05–0.15 wt% of the bitumen mass to avoid viscosity peaks and pump stalls. Because the density of SBS (0.94–0.96 g/cm³) is lower than that of bitumen (1.02–1.04 g/cm³), storage separation is controlled primarily by particle size reduction and network formation rather than by density equalization. ASTM D7173 tube testing at 163 °C for 72 h remains the controlling method for separation.

Compared with SBS 1301, the 40 wt% styrene grade produces a higher PMB softening point and better rutting resistance at equal loading, but also higher low-temperature stiffness. Plants that face both cold-climate cracking and summer rutting often blend 1401 with a minor fraction of SBS 1301 or an oil-extended grade; the blend ratio is validated by ASTM D7173 until the top-to-bottom softening-point difference stays below the local highway agency limit, commonly ≤ 2.5 °C.

When 1401 Replaces SBS 1301 in Solvent-Borne and Hot-Melt Adhesives

If 1401 replaces a 30 wt% styrene grade in solvent-borne contact adhesives, the higher polystyrene fraction raises cohesive strength and heat resistance while increasing solution viscosity at equal solids. A 20 wt% solution in toluene may exhibit a Brookfield viscosity of 800–2,000 mPa·s at 25 °C, whereas an SBS 1301 solution at the same concentration may fall between 400–1,000 mPa·s. Spray-grade formulations therefore reduce solids to 15–18 wt% or use a solvent blend such as 70:30 toluene/ethyl acetate to maintain sprayability. Production-scale dissolvers with slow-speed anchor agitators at 0.5–1.0 m/s tip speed commonly require 4–8 h to dissolve whole pellets; crumb can be dispersed within 1–2 h under the same conditions.

T-peel values reported for generic linear SBS with 40 wt% styrene in solvent-borne PVC/aluminum bonds fall between 2.5–4.5 N/mm after 7 days at 23 °C and 50% RH, tested according to ISO 11339:2022. Published T-peel data specific to Shandong Jusage SBS 1401 in this configuration is limited; the range should be treated as a formulation screen, not a guaranteed value. In shoe-sole compounds, 1401 is compounded with polystyrene, naphthenic oil, calcium carbonate, and antioxidants in a twin-screw extruder with L/D 40:1 and barrel temperatures of 140–170 °C. The 40 wt% styrene architecture yields higher hardness and abrasion resistance than SBS 1301, but winter-grade recipes often blend 10–20 phr of an oil-extended or lower-styrene SBS to prevent cold-cracking.

In hot-melt pressure-sensitive adhesives, 1401 can be formulated with C5 tackifier resin at 100–120 phr and naphthenic oil at 20–40 phr. Mixing is performed in a sigma-blade kneader under nitrogen blanket at 160–180 °C until the resin is dispersed and the compound has uniform clarity. Loop tack and 180° peel adhesion on stainless steel are tested according to ASTM D6195 and ASTM D3330/D3330M-18; however, published data specific to Shandong Jusage SBS 1401 in hot-melt systems is limited, so end users should generate compound-specific data.

In comparison with radial or coupled SBS grades, linear 1401 typically exhibits lower zero-shear viscosity at equal styrene content and molecular weight because the linear chain has fewer entanglements per molecule than a radial arm structure. This reduces mixer energy input during bitumen modification but can also reduce die swell in profile extrusion. Radial grades may provide higher tensile strength and elastic recovery because the star architecture creates multiple physical crosslink points; however, they generally require higher processing temperatures. Oil-extended grades contain 30–50 phr of aliphatic or naphthenic oil, making them easier to handle in injection-molded soling but diluting the styrene network and reducing tensile strength. Shandong Jusage SBS 1401, as an unextended linear grade, occupies the intermediate position between SBS 1301 and SBS 1501 in hardness, tensile strength, and upper service temperature.

Table 2 is a comparative guide based on generic linear SBS grade nomenclature. The linear SBS 1401 class is not identical to the specific Shandong Jusage product in every lot, and data from the manufacturer’s certificate should replace these guide values for release purposes.

Polypropylene Impact Modification and Thermal Stability Limits

Compounding of polypropylene homopolymer with 1401 is performed at 5–15 wt% loading. A co-rotating twin-screw extruder with L/D 40:1, specific energy input of 0.18–0.25 kWh/kg, and melt temperature below 220 °C is used. Residence times above 60 s at temperatures above 210 °C can create gel particles from the unsaturated butadiene midblock. Notched Charpy impact strength according to ISO 180:2019 typically increases sharply up to 10 wt% and then plateaus; above 15 wt%, the tensile yield stress of an unfilled PP homopolymer compound may fall below 22 MPa. The compound should contain 0.05–0.10 wt% of a hindered phenolic antioxidant and should not be combined with copper-containing heat stabilizers because copper ions accelerate oxidative degradation of the butadiene phase.

Moisture control is necessary before compounding. Pellets stored at relative humidity above 60% can absorb 0.2–0.4 wt% water, and pre-drying at 70–80 °C for 2 h is recommended before extrusion. The polymer is also incompatible with high-aromatic process oils above 20 phr because aromatic fractions plasticize the polystyrene domains and reduce the upper service temperature of the compound. Naphthenic or paraffinic oils are preferred when oil extension is required. No published food-contact data specific to this Shandong Jusage grade has been identified; end users requiring FDA 21 CFR 177.1810 clearance or equivalent regional food-contact approvals should request a specific compliance letter from the supplier before use.

Common commercial packaging is 20 kg or 25 kg multiwall paper bags with polyethylene liners. Storage should be below 30 °C in a dry area, and pallets should not be stacked more than 3 high to avoid cold-flow compaction. Under these conditions, melt flow rate and solution viscosity remain stable for 24 months in typical warehouse practice; the lot-specific shelf-life statement on the certificate of analysis is the controlling document. This product should not be stored near strong oxidizing agents or exposed to direct sunlight for extended periods, because ultraviolet irradiation of the butadiene phase accelerates surface crosslinking and gel formation.