TY - JOUR
T1 - New polyolefin elastomers containing "reactive" p-methylstyrene units
T2 - Preparation by metallocene catalysts
AU - Chung, T. C.
AU - Lu, H. L.
AU - Hong, S.
PY - 1999
Y1 - 1999
N2 - This paper summarizes the experimental results of three new polyolefin elastomers, i.e., poly(1-octene-co-p-methylstyrene (O-p-MS), poly(ethylene-ter-propylene-ter-p-methylstyrene) (EP-p-MS) and poly(ethylene-ter-1-octene-ter-p-methylstyrene) (EO-p-MS), containing "reactive" p-MS units. Both Ziegler-Natta and metallocene catalysts were used in studying co-and ter-polymerization reactions. In the copolymerization of 1-octene and p-MS, Ziegler-Natta catalyst TiCl3/AlEt3 exhibits higher catalyst reactivity to produce high molecular weight O-p-MS copolymers, containing up to 20 mol % p-MS. However, the copolymers show very broad composition and molecular weight distributions. On the other hand, two EP-p-MS and EO-p-MS terpolymers with narrow molecular weight and composition distributions were prepared by [C5Me4(SiMe2N1Bu)]TiCl2 metallocene catalyst with constrained ligand geometry. The sharp glass transition temperature (Tg) with flat baseline in each differential scanning calorimetry (DSC) curve indicates homogeneous terpolymer microstructures. The Tg of EP-p-MS is very sensitive to the terpolymer composition (ethylene/propylene ratio and p-MS content). In the compositions with ideal ethylene/propylene ratio ∼ 55/45, the Tg is almost proportional to the content of p-MS. Only with the concentration of p-MS < 2 mol %, does the EP-p-MS show a low Tg < -45 °C. On the other hand, the EO-p-MS system exhibits a low Tg < -50 °C in a wide range of copolymer compositions, even ones with relatively high p-MS contents (> 7 mol %).
AB - This paper summarizes the experimental results of three new polyolefin elastomers, i.e., poly(1-octene-co-p-methylstyrene (O-p-MS), poly(ethylene-ter-propylene-ter-p-methylstyrene) (EP-p-MS) and poly(ethylene-ter-1-octene-ter-p-methylstyrene) (EO-p-MS), containing "reactive" p-MS units. Both Ziegler-Natta and metallocene catalysts were used in studying co-and ter-polymerization reactions. In the copolymerization of 1-octene and p-MS, Ziegler-Natta catalyst TiCl3/AlEt3 exhibits higher catalyst reactivity to produce high molecular weight O-p-MS copolymers, containing up to 20 mol % p-MS. However, the copolymers show very broad composition and molecular weight distributions. On the other hand, two EP-p-MS and EO-p-MS terpolymers with narrow molecular weight and composition distributions were prepared by [C5Me4(SiMe2N1Bu)]TiCl2 metallocene catalyst with constrained ligand geometry. The sharp glass transition temperature (Tg) with flat baseline in each differential scanning calorimetry (DSC) curve indicates homogeneous terpolymer microstructures. The Tg of EP-p-MS is very sensitive to the terpolymer composition (ethylene/propylene ratio and p-MS content). In the compositions with ideal ethylene/propylene ratio ∼ 55/45, the Tg is almost proportional to the content of p-MS. Only with the concentration of p-MS < 2 mol %, does the EP-p-MS show a low Tg < -45 °C. On the other hand, the EO-p-MS system exhibits a low Tg < -50 °C in a wide range of copolymer compositions, even ones with relatively high p-MS contents (> 7 mol %).
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U2 - 10.5254/1.3538801
DO - 10.5254/1.3538801
M3 - Article
AN - SCOPUS:0040675778
SN - 0035-9475
VL - 72
SP - 283
EP - 298
JO - Rubber Chemistry and Technology
JF - Rubber Chemistry and Technology
IS - 2
ER -