SYNTHESIS OF iPS-b -iPP BLOCK COPOLYMER WITH SN CATALYST Ⅰ.EFFECT OF POLYMERIZATION PARAMETERS ON SEQUENTIAL BLOCK COPOLYMERIZATION OF STYRENE WITH PROPYLENE
XU Guangxue, UN Shang' an. SYNTHESIS OF iPS-b -iPP BLOCK COPOLYMER WITH SN CATALYST Ⅰ.EFFECT OF POLYMERIZATION PARAMETERS ON SEQUENTIAL BLOCK COPOLYMERIZATION OF STYRENE WITH PROPYLENE[J]. Acta Polymerica Sinica, 1996,(4):416-422.
XU Guangxue, UN Shang' an. SYNTHESIS OF iPS-b -iPP BLOCK COPOLYMER WITH SN CATALYST Ⅰ.EFFECT OF POLYMERIZATION PARAMETERS ON SEQUENTIAL BLOCK COPOLYMERIZATION OF STYRENE WITH PROPYLENE[J]. Acta Polymerica Sinica, 1996,(4):416-422.DOI:
Sequential block copolymerization of styrene with prOPylene were carried out with TiO4-NdojOR)
/MgCl2 /Ph2SiO2 / EB catalyst (called SN catalyst) which was developed in our laboratory. The influence of various polymerization conditions such as styrene prepolymerization time
monomer feed ratio
extend donor (EB)
Al(iBu). concentration
catalyst concentration and temperature on the copolymerization were studied in detail' Ethyl benzoate was found to reduce the activity of the catalyst.A much higher incorporation of styrene and higher stereoregularity of each segments of copolymer
however
were observed within mole ratio EB/Ti=5;while futher addition of EB reduced incorporation of styrene and suppressed the stereospecificity of PS segment. SN catalyst was found to give higher catalytic yield (over 1000gP/gTi) and conversion yield of styrene.The styene-units of copolymer obtained were whithin 15 to 85 mile%