Overview

SIS polymer, also known as Styrene-Isoprene-Styrene (SIS) block copolymer or styrene-isoprene rubber, is a styrenic block copolymer (SBC) thermoplastic elastomer (TPE). In formulated systems, SIS polymer is commonly paired with hydrocarbon tackifier resins, plasticizing oils, and antioxidants to target specific viscosity, open time, and adhesion profiles. Guangju Yida is a reliable SIS polymer supplier for adhesive and compounding production.

General Description

SIS polymer is a linear triblock structure (PS–PI–PS), where polystyrene (PS) end-blocks form physical crosslinks and the polyisoprene (PI) mid-block provides elasticity. These PS domains soften on heating, enabling reversible flow and easy reprocessing compared with vulcanized rubber. Industrially, SIS is commonly produced by living anionic polymerization: purified isoprene is polymerized first, followed by styrene addition to build the end blocks, then the polymer is finished, pelletized, and stabilized for processing. SIS can be melt-blended for hot-melt systems or dissolved for solvent-based adhesive manufacturing, depending on the target process.

SIS Product Line of Guangju Yida

The following SIS polymer grade list is provided for quick specification alignment during sourcing, qualification, and formulation work at Guangju Yida.

Grade	ST%	Di-Block%	Tolune Solution Viscorsity (mPa ·s, 25 wt% in toluene; 25°C)	Meltfolw rate (g/10min, 200°C / 5.0 kg)	Alternative grades
SIS XJ-9015	15	<1	1000-1500	8-16	YH-1105 Sinopec Baling
SIS XJ-9116	16	16	700-1000	8-16	YH-1106 Sinopec Baling
SIS XJ-9029	30	<1	200-400	8-16	YH-1209 Sinopec Baling

Key Features & Benefits

High tack potential and good compatibility with tackifier resins and process oils

Thermoplastic processing: fast melt blending, extrusion, and hot-melt coating

Soft feel with low hardness options and strong elastic recovery

Tunable viscosity and cohesion via styrene content and molecular weight control

Excellent low-temperature flexibility for labels, tapes, and sealants

Applications

Pressure-sensitive adhesives for packaging tapes, labels, and protective films

Hot melt adhesive SIS formulations for hygiene, woodworking, and assembly

Rubber modification for bitumen/asphalt, sealants, and damping compounds

Flexible polymer blends for grips, soft-touch overmolding, and footwear parts