Rheological properties of two high polymers suspended in an abrasive slurry jet
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
e-Polymers 2021; 21: 186–193
Research Article
Xinyong Wang, Dapeng Zhou, Guodong Zhu, and Chuwen Guo*
Rheological properties of two high polymers
suspended in an abrasive slurry jet
https://doi.org/10.1515/epoly-2021-0005
received June 24, 2020; accepted November 20, 2020
1 Introduction
Abstract: With high polymer added into suspension, the The abrasive slurry jet (ASJ) is a suspension consisting of
use of abrasive slurry jet (ASJ) has significant advantages abrasive particles and a high polymer solution, which is
in energy management. The quality and efficiency of ASJ a non-traditional machining tool (1). Cutting glass with
are affected distinctly by its structure and the flow field new water-soluble polymer is one of its applications and
feature, both of which depend on the rheological proper- was conducted by Anjajah (2), whose work showed that
ties of the abrasive slurry. Therefore, this paper carries
the polymer concentration and abrasive type affected
out a series of experiments to study the rheological prop-
the cutting depths mostly. Liao et al. (3) applied ASJ on
erties of abrasive slurry with polyacrylamide (PAM) and
the experimental glass polishing, in which the polished
carboxy methyl cellulose (CMC) commonly used in ASJ.
glass had a very small roughness. The abrasive water jet
The paper also explores the effect of temperature and
(AWJ) was compared with ASJ by Nouraei et al. (4,5) and
abrasive on the apparent viscosity of the abrasive slurry.
revealed the suppression on jet divergence by the added
Experimental results show that PAM and CMC solutions
behave as a pseudoplastic non-Newtonian fluid in the polymer. New technical cutting equipment of ASJ to cut
selected concentration range, whose apparent viscosity and drill glass was developed by Pang et al. (6,7), which
increases with the concentration. In addition, specific showed that the new equipment had advantages in the
non-Newtonian fluid constitutive equations of the power- performance of glass grooving and punching.
law model for PAM and CMC solution were obtained by Polyacrylamide (PAM) and carboxy methyl cellulose
nonlinear fitting calculation. The apparent viscosity (CMC) are the mostly used polymer additives in ASJ. PAM
decreases with the growth of temperature because it is an important type of water-soluble polymer with spe-
leads to the increase in spacing between molecules, cial physicochemical properties. It can be obtained by
making the attraction between molecules smaller and grafting or cross-linking a variety of modified structures
smaller. However, the abrasive has no influence on the of branched or network structure (8). CMC is a carboxy-
apparent viscosity of abrasive slurry for these molecular methylated derivative of cellulose, also known as the
bonds, and their mechanical entanglements are not cellulose gum, which has been widely used because of
destroyed by abrasive particles in the suspension. its many special properties, such as thickening, adhe-
Keywords: ASJ, rheological properties, high polymer, sion, film formation, water holding, emulsification, and
apparent viscosity, rotational viscometer suspension (9). Recent studies have shown that CMC
hydrogels have good biocompatibility and can be applied
to biomedical applications such as soft tissue enhance-
ments (10).
In the study of rheological properties of high polymer
* Corresponding author: Chuwen Guo, School of Electrical and
solutions, the effects of pH, concentration and reaction
Power Engineering, China University of Mining and Technology,
Xuzhou, 221116, China, e-mail: cwguo@cumt.edu.cn
temperature on apparent viscosity, and interfacial ten-
Xinyong Wang: School of Electrical and Power Engineering, China sion of surface-active polymer solutions are investigated
University of Mining and Technology, Xuzhou, 221116, China by Li et al. (11). The rheological properties of partially
Dapeng Zhou: China Coal Technology Engineering Group Huaibei hydrolyzed PAM have been improved by Hu et al. (12)
Blasting Technology Research Institute Limited Company, Huaibei,
through using silica nanoparticles for enhanced oil
235099, China
Guodong Zhu: Shandong Boran Enterprise Management Consulting recovery. Ujjwal et al. (13) investigated the rheological
Co., Ltd., Jinan, 250000, China properties of a random copolymer PAM-ran-PAH and
Open Access. © 2021 Xinyong Wang et al., published by De Gruyter. This work is licensed under the Creative Commons Attribution 4.0
International License.
Rheological properties of two high polymers suspended in an abrasive slurry jet 187
polydactyly hydrazide (PAH) at different temperatures depends on the rheological properties of abrasive slurry
and salinity. Results showed that PAM-ran-PAH was in ASJ, which determines its structure and flow field fea-
more stable than PAH in saline and high-temperature ture and then affects its cutting quality and efficiency.
environments. Karimi et al. (14) investigated the rheolo- Therefore, this paper studies the rheological properties
gical, physical stability, and sensory properties of milk- of the suspension in ASJ. With the non-Newtonian fluid
jujube concentrate mixture at different concentrations category of the abrasive slurry explored, constitutive
of pectin and CMC. Senapati and Mishra (15) developed equations under different composition ratios are calcu-
a hydrostatic head viscometer and its novel viscosity lated by a nonlinear fitting model. Finally, this paper
equation to determine the flow characteristics of some investigates the effects of temperature and abrasive on
high polymer solutions. Haeri and Hashemabadi (16) the apparent viscosity of the abrasive slurry.
researched the rheology, surface tension, and contact angle
of falling film at three different CMC solution concentra-
tions. Ghannam (17,18) studied the rheological properties
of all-aqueous and aqueous/NaCl solution of PAM and 2.2 Experimental system
obtained that the solution exhibited the non-Newtonian
behavior with shear thinning and shear thickening areas. Figure 2 shows the testing system of the slurry apparent
Based on previous researches, ASJ shows great viscosity, which consists of a rotational viscometer, a
advantages in the field of material manufacturing. constant temperature water bath, a thermometer, and a
However, the rheological properties of suspension in laptop. The rotational viscometer is used for measuring
ASJ have not been fully studied, which will significantly the apparent viscosity of the abrasive slurry, the constant
affect the cutting quality and efficiency of ASJ. Although temperature water bath for keeping the temperature
rheological properties of certain high polymer solutions of slurry constant, the thermometer for monitoring the
have been researched, most of them are used in crude oil temperature of slurry in real-time, and the laptop for
recovery. Therefore, rheological properties of suspension recording the value of apparent viscosity measured by
with PAM and CMC commonly used in ASJ were studied the rotational viscometer through snoop ware.
in this paper, which can provide guidance to make up ASJ An NDJ-79A rotational viscometer was adopted in the
suspension in engineering works. experiments, which has a torque sensor that can measure
the torque of the rotor applied by tested abrasive slurry.
According to Eq. 1–3, the apparent viscosity can be cal-
culated and visualized on the screen of rotational visc-
2 Experiments ometer (19).
τ = M /(2πhr 2), (1)
2.1 Research object
γ̇ = 2w /[1 − (r / R)2 ] = 4πn /[1 − (r / R)2 ], (2)
Figure 1 shows the structure of ASJ at 10 MPa taken by a η = τ/ γ̇ , (3)
high speed camera. ASJ converges better than water jet where τ is shear stress, γ̇ shear rate, η apparent viscosity,
does, which is more distinct with the increase in high M torque, h length of the rotor, r radius of the rotor, R
polymer concentrations. The converging characteristic angular speed, and n spindle speed.
Figure 2: Experimental system: 1 – constant temperature water bath,
Figure 1: Structure of ASJ. 2 – rotational viscometer, 3 – thermometer.
188 Xinyong Wang et al.
Table 1: Parameters of high polymers Table 2: Details of the experimental variables
Polymer Appearance MW DS Solid content Variables Details
PAM White particles 12 million — ≥89% High polymer PAM, CMC
CMC White powder 240.2 0.55 — Concentration (g/L) 18.52/25.93/33.33/40.74/48.15
Spindle speed (rpm) 100/150/200/250/300/350/400/
450/500/550/600/650/700/750
Temperature (°C) 20/25/30/35/40
Abrasive Garnet, 100 meshes, 10% volume
2.3 Experimental scheme fraction
PAM and CMC are the high polymer additives commonly
used in ASJ. The technical information of the two high
polymers is listed in Table 1. Choosing the aqueous solu- solution link each other through molecular bonds, form-
tion of PAM and CMC as the experimental object, this ing a net structure finally with mechanical entanglement
paper carried out three parts of experiments to study between molecular bonds. At a low shear rate, the net
the rheological properties of the abrasive slurry. First, structure destroyed by the rotor will recover in a short
to obtain the non-Newtonian category and constitutive period so that the apparent viscosity can be maintained
equations of abrasive slurry, a full factorial experiment at a higher level. However, at a high shear rate the
method was adopted under five kinds of high polymer damaged net structure cannot be recovered in time, so
concentrations and 14 kinds of spindle speeds. Selected that the apparent viscosity of PAM solutions measured is
concentrations were applicable to the ASJ system as very small.
shown in Figure 2. Then, the experimental measurement In addition, Figure 3 shows that the apparent visc-
of slurry apparent viscosity was conducted under five osity of PAM solutions increases with PAM concentra-
kinds of temperatures to explore the effect of temperature tions. The intermolecular attraction of PAM solution is
on slurry apparent viscosity. very small because of the less and weak molecular bonds
Finally, the apparent viscosity of the abrasive slurry at a low PAM concentration, which caused a decrease in
with 10% volume fraction garnet (100 meshes) was mea- the apparent viscosity. However, with the increase in
sured to explore the effect of abrasive on slurry apparent PAM concentrations, hydrogen bonds between the mole-
viscosity. The details of the above experimental variables cules will increase in PAM solutions, forming a mesh
are presented in Table 2. structure gradually and increasing solution’s apparent
viscosity finally.
3 Results and discussion
3.1 Non-Newtonian fluid category of
suspension in ASJ
3.1.1 Non-Newtonian fluid category of PAM solution
Figure 3 shows the apparent viscosity of the PAM solution
at different spindle speeds and high polymer concentra-
tions. Because of the high minimum range of torque sen-
sors, the apparent viscosity of 18.52 g/L PAM solutions
cannot be measured when the spindle speed is less
than 200 rpm. The apparent viscosity of PAM solutions
declines with the increase in shear rate, which illustrates
that it is a pseudoplastic non-Newtonian fluid in the Figure 3: Apparent viscosity of PAM solutions at different shear
selected concentration range. The molecules of PAM rates and concentrations.
Rheological properties of two high polymers suspended in an abrasive slurry jet 189
3.1.2 Non-Newtonian fluid category of CMC solution experimental data based on non-Newtonian fluid cate-
gory research of the abrasive slurry. With PAM and
Figure 4 shows the apparent viscosity of CMC solutions at CMC solutions being pseudoplastic non-Newtonian fluid,
different spindle speeds and high polymer concentra- the power-law model shown in Eq. 4 can be adopted in a
tions. Because of the large range of the apparent viscosity nonlinear fitting calculation:
of CMC solutions, three rotors were used to measure it at a
τ = kγ̇ n, (4)
suitable PAM concentration. Therefore, three different
shear rates correspond to one spindle speed. where k is a consistency coefficient, which represents the
As shown in Figure 4, the apparent viscosity of the average viscosity of the fluid; n is a flow index, which is a
CMC solution decreases with the increase in shear rate as measure of the deviation of fluid from Newtonian.
well as the PAM solution. Similarly, the CMC solution is a
pseudoplastic non-Newtonian fluid too. The CMC solu-
tion is the same as the PAM solution in the molecular 3.2.1 Non-Newtonian fluid constitutive equation of PAM
structure, which looks like a net with molecular bonds solution
and its mechanical entanglement. Moreover, the apparent
viscosity of a CMC solution increases with the CMC con- Figure 5 compares the rheological properties curves of
centration, which is similar to the PAM solution. The only PAM solution at different concentrations, which illus-
difference is that the CMC solution is much larger than trates the relationship between the shear stress and the
the PAM solution in apparent viscosity at the same con- shear rate. The shear stress increases sharply at the lower
centration and shear rate. Therefore, the CMC solution is range of the shear rate, whereas it increases slowly at the
much larger than the PAM solution in intermolecular higher range, leading to a similar conclusion of non-New-
attraction with stronger molecular bonds and more com- tonian fluid mentioned in Section 3.1. As shown in Table 3,
plicated mechanical entanglement. this section also obtained the specific constitutive equa-
tion of PAM solution at different concentrations through
the nonlinear fitting calculation.
In Table 3, Ek and En represent the standard deviation
3.2 Non-Newtonian fluid constitutive of consistency coefficient k and flow index n, respectively.
equation of suspension in ASJ All ratios of the standard deviation to the consistency
coefficient are about 10%, whereas ratios of the standard
To explore the rheological properties and get the non- deviation to flow index are under 5%. R2 is the fitting
Newtonian constitutive equation of the abrasive slurry confidence of the constitutive equation of PAM solution,
at different high polymer concentrations, the section whose values are more than 0.98. A high value of R2
used Origin software to carry out nonlinear fitting for shows the consistency between the experimental data
Figure 4: Apparent viscosity of CMC solution at different shear rates
and concentrations. (a) Concentrations: 25.93–48.15 g/L, (b) con-
centration: 18.52 g/L. Figure 5: Rheological properties curve of PAM solution.
190 Xinyong Wang et al.
Table 3: Results of nonlinear fitting calculation for PAM solution
Concentration (g/L) Equation k Ek n En R2
18.52 τ = kγ̇ n 0.078 0.012 0.845 0.019 0.995
25.93 0.516 0.051 0.632 0.013 0.996
33.33 1.015 0.129 0.555 0.017 0.991
40.74 1.758 0.163 0.491 0.012 0.993
48.15 3.241 0.358 0.427 0.015 0.987
and fitting results, which can reveal the rheological prop- and PAM solutions, which indicates that CMC solution is
erties of PAM solutions veritably. larger than water and PAM solutions in viscosity. The
Table 3 also shows that all values of consistency coef- viscosity of a CMC solution increases with the growth of
ficient k are much larger than the viscosity of water concentration. In addition, flow index n will decrease
(0.001 Pa s), which indicates that PAM solutions are gently with the increase in CMC concentration. The CMC
larger than water in viscosity. In addition, the viscosity solution shows the rheological characteristic of shear-
of PAM solutions increases with the growth of concentra- thinning, obviously among the concentration range in
tion. Flow index n will decrease distinctly with the experiments.
increase in PAM concentrations. PAM solution is similar
to the Newtonian fluid at lower concentrations, whereas
it shows the rheological characteristic of shear-thinning 3.3 Effects of temperature on the apparent
at higher concentrations.
viscosity of suspension in ASJ
To explore the effect of temperature on slurry apparent
3.2.2 Non-Newtonian fluid constitutive equation of CMC viscosity, this section measured the apparent viscosity of
solutions PAM and CMC solution under a constant shear rate
(2616.67 s−1) and different temperatures. With five kinds
Figure 6 compares the rheological properties curves of of concentrations and temperatures listed in Table 2, the
CMC solutions at different concentrations, which illus- experimental scheme for PAM solutions does not change,
trates the relationship between shear stress and shear whereas the experimental scheme for CMC solution has
rate. The shear stress increases sharply at the lower range been changed for the limitation of the measuring range of
of shear rate, whereas it increases slowly at the higher the rotational viscometer. Lower concentrations were
range, corresponding to the result of non-Newtonian used to study the effect of temperature on the apparent
fluid in Section 3.1. As shown in Table 4, this section viscosity of CMC solutions.
also obtained the specific constitutive equation of CMC
solutions at different concentrations through the non-
linear fitting calculation.
In Table 4, Ek and En represent the standard deviation
of consistency coefficient k and flow index n, respectively.
R2 is the fitting confidence of the constitutive equation of
CMC solutions. The fitting calculation for CMC solution at
the lowest and highest concentrations is less precise, in
which ratios of the Ek exceed 15% and ratios of the En are
about 10%. However, it is accurate among the middle
concentration range. In this range, most of the ratios of
the Ek and En are less than 5% with high fitting confi-
dence, and R2 are more than 0.99. Overall, the results
of the nonlinear fitting can reveal the rheological proper-
ties of CMC solutions.
Table 4 also shows that all values of consistency
coefficient k are much larger than the viscosity of water Figure 6: Rheological properties curve of CMC solution.
Rheological properties of two high polymers suspended in an abrasive slurry jet 191
Table 4: Results of nonlinear fitting calculation for CMC solutions
Concentration (g/L) Equation k Ek n En R2
18.52 τ = kγ̇ n 5.745 1.401 0.394 0.033 0.934
25.93 6.098 0.298 0.409 0.009 0.995
33.33 6.858 0.429 0.467 0.011 0.994
40.74 14.857 0.709 0.431 0.010 0.994
48.15 16.202 2.438 0.490 0.031 0.962
Figure 7 shows that the apparent viscosity of PAM 3.4 Effects of abrasive on the apparent
solutions is affected by temperature distinctly and is viscosity of suspension in ASJ
inversely proportional to temperature, especially at the
lower concentration. The reason is that the spacing To explore the effect of abrasive on the apparent viscosity
between molecules of PAM solutions increases with tem- of the abrasive slurry, 80 mesh garnet was adopted in an
perature, causing a smaller attraction between molecules. experiment, whose volume fraction was constant (10%).
The internal fraction is proportional to the attraction It has been widely used in AWJ cutting machines, and the
between molecules, which determines the apparent visc- volume fraction is suitable for material manufacturing
osity of PAM solutions. The apparent viscosity of PAM with ASJ. The concentration of high polymer is 18.52 g/L
solutions at lower concentrations is apt to be affected in the experiment that the apparent viscosity measure-
by the change in temperature. ment of PAM and CMC solutions can be in the same range
Figure 8 shows that the apparent viscosity of CMC of shear rates.
solutions is affected by temperature distinctly and has As shown in Figure 9, PAM and CMC solutions with
an inversely proportional relationship with tempera- abrasive are slightly larger than the one without abrasive
ture. The reason is that the spacing between molecules in apparent viscosity. Molecular bonds and their mechan-
of CMC solution increases with temperature, leading to ical entanglements in the solution were not destroyed by
a smaller attraction between molecules. The internal abrasive particles. The force between molecules keeps
fraction is proportional to the attraction between mole- unchanged. Thus, the apparent viscosity and rheological
cules, which determines the apparent viscosity of CMC properties of PAM and CMC solutions are still dominated
solutions. by the net molecular structure. However, abrasive
Figure 7: Apparent viscosity of PAM solution under different Figure 8: Apparent viscosity of CMC solution under different
temperatures. temperatures.
192 Xinyong Wang et al.
properties of ASJ, which also can provide guidance for
the engineering application of ASJ.
Acknowledgment: This work was supported by the
Fundamental Research Funds for the Central Universities
(2017XKZD02).
References
(1) Hollinger RH, Perry WD, Swanson RK. Precision cutting
with a low pressure coherent abrasive suspension jet.
In: 5th American Waterjet Conference. Toronto; 1989.
p. 245–52.
Figure 9: Effect of abrasive on the apparent viscosity of the abrasive
(2) Anjaiah D, Chincholkar AM. Cutting of glass using low pres-
slurry.
sure abrasive water suspension jet with the addition of zyco-
print polymer. In: 19th International Conference on Water
particles raise the friction between the rotor and slurry,
Jetting; 2008. p. 105–19.
leading to a small increase in the apparent viscosity. (3) Liao Y, Wang C, Hu Y, Song YX. The slurry for glass polishing by
micro abrasive suspension jets. Adv Mater Res. 2009;69/
70:322–7.
(4) Nouraei H, Wodoslawsky A, Papini M, Spelt JK. Characteristics
4 Conclusions of abrasive slurry jet micro-machining: a comparison with
abrasive air jet micro machining. J Mater Process Technol.
In this paper, a series of experiments were carried out to 2013;213(10):1711–24.
study the rheological properties of abrasive slurry with (5) Nouraei H, Kowsari K, Spelt JK, Papini M. Surface evolution
models for abrasive slurry jet micro-machining of channels
PAM and CMC commonly used in ASJ, and the effect of
and holes in glass. Wear. 2014;309(1–2):65–73.
temperature and abrasive on the apparent viscosity of the (6) Pang KL, Nguyen T, Fan JM, Wang J. Modelling of the micro-
abrasive slurry is discussed. Specific experimental results channelling process on glasses using an abrasive slurry jet. Int
were shown as follows: J Mach Tools Manuf. 2012;53(1):118–26.
1. PAM and CMC solutions are pseudoplastic non-Newtonian (7) Pang KL, Nguyen T, Fan JM, Wang J. A study of micro-chan-
neling on glasses using an abrasive slurry jet. Mach Sci
fluids within a selected concentration range, and
Technol. 2012;16(4):547–63.
their apparent viscosity increases with concentration.
(8) Zhang D, Zhao W, Wu Y, Chen Z, Li X. Facile droplet micro-
Under the same concentration and shear rate, the fluidics preparation of larger PAM-based particles and inves-
apparent viscosity of CMC solutions is much greater tigation of their swelling gelation behavior. E Polym.
than that of the PAM solution. The increment comes 2019;19(1):579–93.
from the greater intermolecular attraction of CMC (9) Niu SY, Hao FG. Progress of sodium carboxymethylcellulose.
Anhui Agric Sci. 2006;34(15):3574–5.
solutions, the stronger molecular bonds, and the
(10) Liu B, Ma X, Zhu C, Mi Y, Fan D, Li X, et al. Study of a novel
more complex mechanical entanglement. injectable hydrogel of human-like collagen and carboxy-
2. The non-Newtonian fluid constitutive equations of methylcellulose for soft tissue augmentation. E Polym.
specific PAM and CMC solutions can be obtained through 2013;13(1):1–11.
nonlinear fitting calculations. (11) Li F, Luo Y, Hu P, Yan X. Intrinsic viscosity, rheological prop-
erty, and oil displacement of hydrophobically associating
3. The apparent viscosity decreases with the increase in
fluorinated polyacrylamide. J Appl Polym Sci.
temperature, which can be explained as that high tem-
2017;134(14):1–9.
perature increases the spacing between molecules. (12) Hu Z, Maje H, Gao H, Ehsan N, Wen D. Rheological properties of
4. Abrasive has no influence on the apparent viscosity of partially hydrolyzed polyacrylamide seeded by nanoparticles.
the abrasive slurry for that molecular bonds, and their Ind Eng Chem Res. 2017;56(12):3456–63.
mechanical entanglements could not be destroyed by (13) Ujjwal RR, Sharma T, Sangwai JS, Ojha U. Rheological
investigation of a random copolymer of polyacrylamide and
abrasive particles in the slurry.
polyacryloyl hydrazide (PAM-ran-PAH) for oil recovery appli-
cations. J Appl Polym Sci. 2017;134(13):1–14.
The results and conclusion of this paper can be used (14) Karimi N, Sani AM, Pourahmad R. Influence of carboxy methyl
to study the formulation optimization and fluid field cellulose (CMC) and pectin on rheological, physical stability
Rheological properties of two high polymers suspended in an abrasive slurry jet 193
and sensory properties of milk and concentrated jujuba mix- (17) Ghannam MT. Rheological properties of aqueous polyacryl-
ture. J Food Meas Charact. 2016;10(2):396–404. amide/NaCl solutions. J Appl Polym Sci. 1999;72(14):1905–12.
(15) Senapati PK, Mishra BK. Rheological characterization of con- (18) Lewandowska K. Comparative studies of rheological proper-
centrated jarosite waste suspensions using Couette & tube ties of polyacrylamide and partially hydrolyzed polyacrylamide
rheometry techniques. Powder Technol. 2014;263:58–65. solutions. J Appl Polym Sci. 2007;103(4):2235–41.
(16) Haeri S, Hashemabadi SH. Experimental study of gravity- (19) Instruction manual for NDJ-79A digital rotational viscometer
driven film flow of non-Newtonian fluids. Chem Eng Commun. (in Chinese) from Baidu library (https://wenku.baidu.com/
2009;196(5):519–29. view/7d83aa23ad02de80d5d84039.html).
You can also read
