Effects of Prepolymerization, Temperature, and Hydrogen Concentration on Kinetics of Propylene Bulk Polymerization Using a Commercial Ziegler-Natta Catalyst

Table 2

Conditions and results of propylene bulk polymerization.

Run no.	(min)	(min)	H2 (MPa)	(°C)	(kgPP/gcat)	MFR (g/10 min)	II (%)	(kgPP/(min·gcat))	(min^-1)
1	0^B, 18^A	61	0.120	70	62.3	48.48	93.19	1.691	0.0217
2	0^B, 21^A	69	0.075	70	65.1	23.13	94.01	1.435	0.0176
3	0^B, 15^A	61	0.030	80	64.3	7.04	97.46	2.327	0.0287
4	0^B, 14^A	59	0.030	70	59.0	5.94	95.89	1.883	0.0251
5	0^B, 14^A	61	0.030	50	16.5	7.56	92.96	0.452	0.0187
6	0^B, 18^A	61	0.030	60	27.9	7.73	93.95	0.800	0.0207
7	0^B, 38^A	251	0	70	33.1	0.013	95.29	0.140	0.0047
8	0^B, 0^A	79	0.030	80	17.2	14.98	94.85	0.516	0.0177
9	0^B, 0^A	62	0.030	60	18.5	8.74	93.03	0.522	0.0148
10	0^B, 0^A	77	0.030	50	12.2	14.51	91.52	0.200	0.0078
11	0^B, 0^A	75	0.120	70	24.3	52.5	89.94	0.541	0.0124
12	0^B, 0^A	86	0.075	70	38.6	27.53	92.14	0.615	0.0087
13	0^B, 0^A	60	0.030	70	30.5	8.19	93.98	0.682	0.0108
14	15^B, 23^A	47	0.030	70	45.1	6.23	95.63	1.436	0.0177
15	30^B, 22^A	60	0.030	70	56.2	6.96	94.82	1.337	0.0178
16	0^B, 0^A	60	0.030	90	9.6	26.91	93.33	NA	NA

A: nonisothermal prepolymerization, during this phase, the reactor temperature increases nearly linearly; B: nonisothermal prepolymerization before raising the reactor temperature; : residence time under different prepolymerization conditions; : reaction time at polymerization temperature ; : reaction yield of polypropylene per gram of catalyst; : initial polymerization rate obtained by extrapolating the reaction rate curve to time zero; other polymerization conditions: 3 mmol TEA, 0.2 mmol CHMCMS donor.