Improving the Thermal Properties of Polycarbonate via the Copolymerization of a Small Amount of Bisphenol Fluorene with Bisphenol A

Table 2

Results of copolycondensation of BPA and BHPF with DPC.

Sample	BPA/BHPF feed ratio (mol/mol)	Yield (%)	^a (g/mol)	^a (g/mol)	PDI^a	^b; (°C)	^c; (°C)	^d; (%)
PAFC-1	99/1	92	20,900	65,000	3.10	203	420	1.68
PAFC-2	98/2	93	21,000	78,000	3.30	205	425	1.70
PAFC-3	97/3	97	23,100	105,000	3.56	207	425	1.75
PAFC-4	96/4	98	24,800	107,000	3.31	210	425	1.76
PAFC-5	95/5	95	28,900	103,000	3.60	210	425	1.85
APC^e	100/0	—	—	—	—	140	320	—

^aDetermined by THF-GPC. ^bMeasured by DSC with a heating rate of 10°C min^-1. ^cDegradation temperature for 5% weight loss was measured by TGA with a heating rate of 10°C min^-1 (with N₂). ^d is calculated by formula (1). ^eParameters of conventional polycarbonate.