A sheet molding compound according to a first aspect of the present invention comprises: a thickened product of a resin composition comprising a vinyl ester resin, a thickener, a polymerization initiator, a polymerization inhibitor and isobornyl methacrylate; and a reinforcing fiber.

A sheet molding compound according to a first aspect of the present invention comprises: a thickened product of a resin composition comprising a vinyl ester resin, a thickener, a polymerization initiator, a polymerization inhibitor and isobornyl methacrylate; and a reinforcing fiber.

A block polymer comprising a first block and a second block is provided. The first block contains aromatic α-mono-olefin units, and the second block contains both 1,3-diene units and mono-olefin units.

A block polymer comprising a first block and a second block is provided. The first block contains aromatic α-mono-olefin units, and the second block contains both 1,3-diene units and mono-olefin units.

A polyolefin-polystyrene multi-block copolymer and a method of producing the same is disclosed herein. In some embodiments, the polyolefin-polystyrene multi-block copolymer has a first complex viscosity of 40,000 Pa.Math.s to 350,000 Pa.Math.s at a temperature of 160° C. and a first frequency of 0.5 rad/s, and has a second complex viscosity of 900 Pa.Math.s to 3,500 Pa.Math.s at a temperature of 160° C. and a second frequency of 125 rad/s. The polyolefin-polystyrene multi-block copolymer has a structure in which polystyrene chains are attached to both ends of a polyolefin chain.

A polyolefin-polystyrene multi-block copolymer and method of making the same is disclosed herein. In some embodiments, a polyolefin-polystyrene multi-block copolymer having a ratio of a loss modulus (E″) to a storage modulus (E′) satisfying the following conditions (a) and (b) over a temperature range of −80° C. to 40° C., wherein the ratio is represented by a loss tangent (tan δ) value and is obtained by dynamic mechanical analysis (DMA), (a) a maximum of the tan δ value in a peak present in the temperature range is 0.20 to 0.35, and (b) a half-width of the peak ranges from 32.0° C. to 50.0° C. The polyolefin-polystyrene multi-block copolymer has a structure in which polystyrene chains are attached to both ends of a polyolefin chain.

A polyolefin-polystyrene multi-block copolymer and a method of making the same are disclosed herein. In some embodiments, a polyolefin-polystyrene multi-block copolymer satisfies conditions (a) to (c) determined by gel permeation chromatography (GPC) and condition (d) determined by .sup.13C NMR, (a) a weight average molecular weight (M.sub.w) of 50,000 g/mol to 150,000 g/mol, (b) a molecular weight distribution of 1.5 to 3.0, a differential of concentration fraction to logarithm of molecular weight as a function of logarithm of molecular weight, obtained from GPC, is modeled to a Gaussian function represented by Equation 1, and (d) a polyolefin block contained in the polyolefin-polystyrene multi-block copolymer includes at least one branched chain. The polyolefin-polystyrene multi-block copolymer has a structure in which polystyrene chains are attached to both ends of a polyolefin chain. The polyolefin-polystyrene multi-block copolymer has excellent mechanical properties such as tensile strength, elongation at break, and modulus.

A block copolymer composition is disclosed herein. In some embodiments, a block copolymer composition includes a diblock copolymer and a triblock copolymer, each including a polyolefin-based block and a polystyrene-based block, wherein the polyolefin-based blocks are present between 45 wt % to 90 wt %, wherein the polystyrene-based blocks are present between 10 wt % to 55 wt %, wherein the difference (ΔT) between a thermal decomposition initiation temperature and a thermal decomposition termination temperature (ΔT) measured by Thermo-Gravimetric Analysis (TGA) is 55° C. or greater, and the diblock copolymer and the triblock copolymer do not have a residual unsaturated bond.

A polybutadiene composition which enables the achievement of a rubber material that has excellent crack propagation resistance and a method for producing this polybutadiene composition are provided. A polybutadiene composition is produced by a method that comprises a step Y wherein 1,3-butadiene is polymerized in the presence of 1,2-polybutadiene and a lanthanoid catalyst. A polybutadiene composition which contains 1,2-polybutadiene and 1,4-polybutadiene, and which is obtained by polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid catalyst.

A block copolymer composition is disclosed herein. In some embodiments, a block copolymer composition has a weight average molecular weight (M.sub.w) of 70,000 g/mol to 120,000 g/mol, a polydispersity index (PDI) of 1.0 to 2.0, a glass transition temperature (T.sub.g) of −55° C. to −30° C., and a melt index (MI), measured at 230° C. and a loading condition of 5 kg, of 0.2 g/10 minutes to 3.0 g/10 minutes. The block copolymer composition has excellent processability.