230316-1 |
230309-2 |
230309-3 |
230316-3 |
230316-4 |
230802-7 * |
230613-8 |
230629-2 * |
230802-3 * |
230629-3 * |
PC , PC60 ( MFI 6 ) |
68 % |
67 % |
66 % |
65 % |
74 % |
81.5 % |
PC , Lexan 141R ( MFI 10 ) |
|
|
|
|
|
|
66 % |
66 % |
70.0 % |
63 % |
Nofia CO6010-EX |
32 % |
32 % |
32 % |
32 % |
24 % |
8 % |
32 % |
32 % |
24.5 % |
32 % |
Phosphazene , SPB-100 |
|
|
|
|
|
3 % |
|
|
3 % |
|
Fyrolflex RDP |
|
|
|
|
|
5 % |
|
|
|
|
Metablen S 2130 |
|
1 % |
2 % |
3 % |
2 % |
2 % |
2 % |
2 % |
2 % |
|
Lotader AX8900 |
|
|
|
|
|
|
|
|
|
5 % |
Joncryl ADR 4400 |
|
|
|
|
|
0.5 % |
|
|
0.5 % |
|
Total |
100 % |
100 % |
100 % |
100 % |
100 % |
100.0 % |
100 % |
100 % |
100 % |
100 % |
P content |
2.10 % |
2.10 % |
2.10 % |
2.10 % |
1.60 % |
1.45 % |
2.10 % |
2.10 % |
1.98 % |
2.10 % |
“ Compounding temp ., ° C , feed to die ”
200 / 225 / 225 / 225 / 220 / 220 / 215 / 215 200 / 265 / 265 / 265 / 260 / 260 / 260 / 260
NI at 3.2mm , J / m 90 360 860 830 800 700 800 790 760 730
UL-94 at 1.6mm |
V-0 |
V-0 |
V-0 |
V-0 |
V-1 |
V-0 |
V-0 |
V-0 |
V-0 |
V-2 |
t max , sec |
6 |
4 |
3 |
6 |
13 |
6 |
7 |
5 |
7 |
15 |
t total , sec |
28 |
21 |
14 |
29 |
49 |
38 |
27 |
24 |
33 |
48 |
# Drips / flaming drips |
0 / 0 |
0 / 0 |
0 / 0 |
0 / 0 |
1 / 0 |
0 / 0 |
2 / 0 |
2 / 0 |
1 / 0 |
3 / 1 |
* PC and Nofia were dried before compounding . In all other formulations , they were in open bag and used as is . |
Figure 2 - Application of Nofia CO6010-EX in PFAS-free FR PC for V-0 at 1.6mm
analogues of PC can be made with phosphorus content from very low levels to > 10 wt %.
These poly ( phosphonate-cocarbonate ) copolymers can be made to be fully miscible with PC , thus making transparent blends . In addition , by varying the reaction conditions ( time , temperature , pressure and catalyst ), polymers of different molecular weight can also be produced . Figure 1 shows a few Nofia grades currently being produced commercially .
Nofia FRs ’ main application has been in PET resin-related systems . They are spun directly into PET fibre for flame retarded technical textiles , carpets , wire and cable braiding , wigs and hair extensions . They are also blended into PET to make very thin ( as low as 13 microns ) and transparent FR BOPET films . In addition , they are used to make FR-TPU and TPEE engineering compounds .
As stated earlier , some Nofia FRs are compatible with PCs and are thus a natural choice for FR-PC , PC blends , and glass-filled PC . FR PC-ABS blends based on Nofia can have an heat deflection temperature ( HDT ) up to 30 º C higher than the typical small molecule FR systems . However , their use in PC resin-related systems is not as widespread as might be expected for their safety profile and mechanical and thermal properties .
One reason for this is the high YI of the Nofia copolymers , such as CO6000 , which prevented its adoption where colour matching , especially white , is important . Another reason is the moisture-sensitivity of Nofia homopolymer , which proved to be difficult to handle for compounders without drying capability .
FRX has developed a new copolymer grade , Nofia CO6010- EX , with much lower YI than the traditional CO6000 . All the grades , including the homopolymers and copolymers , are now pre-dried in the manufacturing facility and packed in moisture-proof packages . The low moisture content ( 400-600 ppm when an uncompromised package is opened ) means they can be used without further drying as long as there is minimal exposure to ambient air before use .
FRX has focused on the application development of Nofia FR in PC and PC blends that are either KPFBS- or PFASfree ( the former still have PTFE present ) as there is a need for both . Below , we present examples of the performance of Nofia FR in both cases . A 27-mm twin-screw extruder was used for compounding . Notched Izod ( NI ) impact strength was measured according to ASTM standard D256 , and an FR test was performed according to UL-94 .
In FR PC – PFAS-free
Figure 2 shows various PFASfree formulations for PC based on Nofia CO6010-EX compounded at different temperatures and moisture content . With about 2 % phosphorus content , the Nofia-only formulations with Metablen * S-2130 as impact modifier achieved the target FR ( i . e . V-0 at 1.6mm ) and excellent impact properties , despite variations in moisture content and processing temperatures . It also further reduced the after-burn time . The formulation with Lotader * AX8900 as impact modifier at 5 %, however , negatively impacted flame retardancy . Phosphorus content lower than 2 % could also achieve V-0 at1.6mm when Nofia FR is used together with phosphazene and / or resorcinol bis ( diphenyl phosphate ( RDP ), as shown in Figure 2 .
58 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981