Research Article
SN Applied Sciences (2020) 2:1577 | https://doi.org/10.1007/s42452-020-03313-w
3 Results and discussion
2.4 Handsheet preparation and characterization
Dried pulps were first beaten to a level of 38°SR and then disintegrated at a pulp consistency of 2% for 10 min at 3000 rpm. Pulp slurry was then diluted to 0.4% prior to the addition of unmodified and modified PCCs. The addi- tion level of filler was 15% based on OD pulp. The stock suspension was then mechanically stirred at 400 rpm for 5 min and transferred to a batch laboratory sheet For- mer so as to achieve a target basis weight of 70 g m −2 according to the TAPPI test method T 205 sp-02. The handsheets were then conditioned in a humidity cham- ber at 23 °C ± 1 °C and relative humidity 50 ± 2% before testing. For determining the filler retention, ash in the paper was estimated by incinerating paper sheets at 525 °C as per the TAPPI standard method T 211 om-93. Thus, filler retention was calculated from the following equation
Both PCC and modified PCC were characterized by dif- ferent analytical tools, FTIR, XRD and TGA to detect the chemical groups, phases present in the dried powders and thermal behavior of the composite fillers, respectively. Thus, spectral data obtained from FTIR reveal valuable information regarding the polymorphs of the fillers dis- tinguished by their different carbonate vibration modes. Our commercial PCC comprises mainly aragonite phases assigned by the following carbonate absorption peaks at 1081, 856, 1494, 713 and 700 cm −1 . These peaks correspond to symmetric stretching ( ؆ 1 ), out-of-plane bending ( ؆ 2 ); doubly degenerate planar asymmetric stretching ( ؆ 3 ) and doubly degenerate pla- nar bending ( ؆ 4 ), respectively. These characteristic peaks of aragonite polymorph have been reported by several researchers [24]. CO 3 2− ions remain inactive in the infra-
R = total weight of ash in paper(g) − ash in control(g) Amount of filler added(g)
(2)
Filler retention, F
× 100
red region and that the band at 1081 cm −1 cannot be seen in the pure calcite phase of calcium carbonate has already been verified in the previous literature [27] [28]. Apart from stretching vibrations, out-of-plane and in- plane bending of C-O bond resembling absorption band at 873 and 712 cm −1 are attributed to calcite phases in the sample [28]. The IR spectra of industrially manufactured PCC used in this study have similar absorption bands as per the published literature data revealed from Fig. 1 [29, 30]. The presence of CH and OH species in the unmodified
Note that control means ash associated with unfilled sheets. Tensile strength was evaluated according to the TAPPI test methods T 494 om-01 by the tensile tester (SE 060, L&W). Other physical properties such as tear and bust were obtained from tear tester (SE009) and burst tester (SE180), respectively. In another experiment, handsheets were sub- jected to spectrophotometer CM 3630 (Konica Minolta). The morphology of the paper samples incorporated with fillers was analyzed by FE-SEM.
Fig. 1 FTIR of A Commercial PCC and PCC modified with chitosans and B distinguished peaks of aragonite and calcite
Vol:.(1234567890)
Made with FlippingBook - Online catalogs