LCY Chemical Huizhou Globalprene® SBS 3411 is a linear styrene-butadiene-styrene triblock copolymer supplied as a porous pellet. In this architecture, polystyrene end-blocks associate into glassy physical crosslink domains at service temperature, while the unsaturated polybutadiene midblock provides elastic recovery and low-temperature flexibility. The grade is produced by anionic solution polymerization and is positioned in the non-oil-extended segment of the LCY Globalprene SBS portfolio. A styrene content in the 31 wt% class yields a balance between cohesive strength and cold-flow resistance for adhesives, bitumen modification, footwear compounding, and impact-modification workflows. Because the midblock retains carbon-carbon unsaturation, the polymer participates in oxidative and free-radical reactions more readily than hydrogenated SEBS grades; antioxidant and process stabilizer selection therefore forms part of every downstream formulation.

What lot-specific properties are released for Globalprene SBS 3411?

Lot-release documentation for linear SBS grades is generally organized around bound styrene content, rheology, mechanical properties of a standard laboratory sheet, and volatiles. Supplier certificates of analysis for 3411 list values obtained under specified sample preparation. The following property envelope is representative of a 31 wt% styrene linear SBS and should not be read as a guaranteed specification unless codified in a supply contract.

The tensile and hardness values are obtained on compression-molded sheets prepared at 150–160°C to remove thermal history. Melt flow rate is not an intrinsic viscosity; it is a single shear-stress extrusion value and does not provide full shear-thinning behavior. Formulators requiring process-relevant viscosity should measure capillary rheometry from 100 s⁻¹ to 10,000 s⁻¹ at 180–200°C in a twin-bore rheometer instead of relying on melt flow rate alone.

Bitumen modification with 3411 is conducted by dispersing 2–6 wt% polymer into a heated bitumen phase at 170–185°C under a rotor-stator mixer, for example a Silverson LSM or equivalent, operating at 3,000–5,000 rpm for 30–60 min. The polybutadiene midblock swells in maltenes while the polystyrene end-blocks remain associated, producing a continuous polymer-rich network when concentration crosses the percolation threshold. Blends are commonly evaluated by ASTM D36 softening point, ASTM D5 penetration, ASTM D4402 dynamic viscosity at 135°C, and ASTM D6084 elastic recovery. Storage stability is assessed by cigar-tube sampling after 48 h at 163°C; phase separation can occur if the aromatic content of the base bitumen is insufficient to solvate the polystyrene domains. Processing above 200°C or with prolonged air injection accelerates oxidative degradation of the unsaturated midblock. Published data for this specific configuration is limited for polymer-modified asphalt formulations containing high reclaimed asphalt pavement content.

Adhesive compounding: solution, hot-melt, and carrier-free systems

Solution adhesives based on 3411 are prepared at 20–40 wt% solids in aromatic, aliphatic, or mixed hydrocarbon solvents; toluene, cyclohexane, and methyl ethyl ketone are common. Brookfield viscosity at 25°C is formulation-dependent but follows the polymer solution viscosity listed above. Tackifier resins such as C5/C9 hydrocarbon resins and rosin esters are added at 50–150 phr relative to polymer to shift glass transition and wetting behavior. The polymer contributes cohesive strength from its polystyrene network; peel and shear are evaluated by ASTM D6195 loop tack, ASTM D3330 180° peel, and ASTM D3654 static shear. Hot-melt formulations are processed in turbine mixers or twin-screw compounders at 160–180°C under nitrogen or in a vacuum vessel; residence times above 2 h at melt temperature are not recommended due to thermal-oxidative degradation and viscosity shift. If porous pellets have been stored at relative humidity above 60%, pre-drying at 60–65°C for 2–3 h in a desiccant dryer is required before melt processing to prevent bubble defects.

When 3411 is compounded with polystyrene or polyolefins, how does the morphology change?

At addition levels of 5–20 wt% in general-purpose polystyrene, 3411 disperses as rubbery domains whose particle size depends on interfacial tension and shear history. Co-rotating twin-screw extruders with L/D 32–40 are typically used, with barrel temperatures from 150°C near the feed throat to 200°C at the die, screw speed 200–350 rpm, and melt temperature held below 210°C to limit degradation. The block copolymer structure reduces interfacial tension and prevents coalescence during processing. Impact performance is measured by notched Izod according to ASTM D256, tensile properties by ASTM D638, and processability by melt flow rate according to ISO 1133-1. In polypropylene and polyethylene, the unsaturated midblock is thermodynamically immiscible; mixing without compatibilizer tends to produce coarse morphologies and poor stress transfer. Low-density polyethylene blends may be used to improve cold-temperature impact, but published data for this specific configuration is limited when the polyolefin phase exceeds 70 wt%.

Footwear compounds containing 3411 are typically batch-mixed in an internal mixer at 120–150°C with polystyrene, process oil, fillers, and blowing agents, then discharged to a two-roll mill for sheeting. Injection molding of SBS-rich compounds is carried out on reciprocating-screw machines with barrel temperatures 160–190°C, injection pressures 60–100 MPa, and mold temperatures 30–60°C. Physical tests follow ASTM D2240 for hardness, ASTM D412 for tensile and elongation, ASTM D624 for tear, and DIN 53516 for abrasion. The unsaturated midblock limits continuous service temperature; soling compounds should be formulated with sufficient antioxidant if prolonged heat ageing at 70°C is specified, using ISO 188 or ASTM D573 as accelerated ageing references.

Positioning Against Oil-Extended SBS and Hydrogenated SEBS

Selection between 3411, oil-extended SBS, and hydrogenated SEBS depends on the balance of cohesive strength, melt viscosity, and ageing resistance. Relative to oil-extended SBS grades, 3411 contains no extender oil; the bulk density is higher and the as-supplied polymer contributes a higher tensile strength and modulus before formulation. Oil-extended grades reduce compound cost and melt viscosity but dilute the polystyrene crosslink density; tensile strength by ASTM D412 is correspondingly lower, and oil migration can change bond peel after ageing. Compared with high-styrene SBS grades, the 31 wt% styrene content of 3411 yields a lower modulus and lower Shore A hardness, which is measured as a softer dry feel in adhesive films and bitumen compounds; grades with 40 wt% styrene or higher give higher hardness and modulus but generally lower low-temperature flexibility. Compared with hydrogenated SEBS, 3411 does not have a saturated polybutadiene midblock. This unsaturation gives broader compatibility with aromatic tackifiers and aromatic bitumen fractions but lower resistance to ultraviolet radiation, oxygen, and elevated-temperature ageing. Continuous service above 70–80°C in air is generally outside the design window for this unsaturated SBS grade; SEBS grades with the same styrene class are specified for higher-temperature or outdoor ageing applications. In processing, 3411 can be run in standard extruders and injection molders without predispersion of oil; however, the melt must not be held above 200°C under air for extended residence times.

For regulatory dossiers, the grade is covered as a styrene-butadiene-styrene block copolymer under the EU REACH polymer exemption, but monomer and additive compliance require supplier confirmation. If the material is intended for food-contact articles, the finished compound must be evaluated under FDA 21 CFR 177.1810 or Regulation (EU) No 10/2011; migration testing must be carried out on the final article under OM2 or OM3 conditions as applicable. Halogenated flame retardants should not be assumed absent; request a material disclosure if IEC 61249-2-21 or RoHS compliance is required. The product is not a medical-grade material; no USP Class VI or ISO 10993 certification should be inferred from the absence of heavy metals on a certificate of analysis.