Study on One-step Process of the Size Mixture Blending and Acidolysis

Modification of Starch

Xiaomei Wanga, Yanming Zhangb

School of Textiles and Clothing, Wuyi University, Jiangmen, Guangdong, 529020, China

awxm@wyu.edu.cn, bzhym@wyu.edu.cn

Keywords: Cassava Starch, Acidolysis Modification, Size Mixture, One-step Process, Viscosity

Abstract. Taking cassava starch as the raw materials and hydrochloric acid (HCL) as the catalyst, the

acidolysis modification of starch was performed combining with the size mixture blending process.

The results show that when the concentration of cassava starch is in the range of 8%~12%, the dosage

of 6% hydrochloride acid for 1000g starch milk is about 0.8g~1.2g, and the viscosity of acidolysis

starch decreases with the increase of hydrochloric acid dosage. The viscosity can reach the stable

level when the reaction time is about 2 hours for the size mixture of low viscosity, and is about 3

hours for that of the high viscosity. Also, the viscosity thermal stability of size mixture is verified to

be good.

Introduction

Acidolysis starch is a kind of modified starch obtained through changing the inherent properties of

raw starch using inorganic acid (such as hydrochloric acid, sulfuric acid, and oxalic acid, etc.) below

the gelatinization temperature of starch such as the corn starch and potato starch [1, 2]. Acidolysis

starch has many advantages that the raw starch does not have, such as low viscosity, high

concentration, and etc, which is suitable for the production of food and chemical industries. But the

process of acid hydrolysis of starch and size mixture blending is relatively complicated and

time-consuming. In this case, the warp sizing researchers hope to obtain a process with short

production cycle, simple equipment, low energy consumption and easy operation.

In recent years, many researchers have been devoted to exploring a production technology of

“one-step process of size mixture blending and acidolysis modification”, which can make the size

mixture blending cost is much lower than only using modified starch [3]. For the one-step process, the

raw starch degradation can be combined with the simple modification in the size mixture blending,

making the "quasi-modified starch" meet the actual requirements of production, the production

process became simple, and the production cost be reduced.

Taking cassava starch as the raw material, one-step process of acidolysis modification and size

mixture blending is studied in this paper. The one-step process saves a lot of time due to leaving out

the dehydration and drying steps of the modified starch. The results of this article provide basis for the

in-depth study on the combination of starch acidolysis and size mixture blending process.

Experimental

Material and Reagents. Cassava starch: Heshan City Huahuang Starch Factory Co. Ltd.

Hydrochloric acid: Analytical reagent, Guangzhou Donghong Chemical Factory. Sodium hydroxide:

Analytical reagent, Tianjin Damao Chemical Reagent Factory.

Experimental Equipments. NDJ-79 rotary viscometer: Shanghai Jinghui Instrument Equipment

Co. Ltd. HHS-6 digital constant temperature water bath kettle: Jiangsu Jintan Ronghua Instrument

Manufacturing Co. Ltd. 501 type digital super constant temperature water bathing kettle: Shanghai

Yueci Electronic Technology Co. Ltd. JHS-2/60 constant speed digital mixer/Blender: Hangzhou

Instrument & Motor Co. Ltd. Electronic balance: Shanghai Yousheng Weighing Apparatus Co., Ltd.

Experimental Methods. Acid hydrolysis of cassava starch and size mixture blending is as

following.

Advanced Materials Research Vols. 821-822 (2013) pp 1122-1125Online available since 2013/Sep/18 at www.scientific.net© (2013) Trans Tech Publications, Switzerlanddoi:10.4028/www.scientific.net/AMR.821-822.1122

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Mix a certain weight of cassava starch and situble water to get 1000g starch milk mixture. Then

put the starch milk into a modified constant temperature water bath kettle with maximum

temperature of 97 °C. The stirring speed was set to 30r/min;

When the temperature of starch milk reached to 50°C, pour a certain weight of 6% hydrochloric

acid into it;

When the temperature reached to 70 °C, the stirring speed was set to 40r/min;

When the temperature reached to 97 °C, the stirring speed was set to 30r/min, then start timing;

When reaching the reaction time required, the concentration of size mixture was diluted to 6%

through adding the boiling water, PH value was neutralized to 7~7.5 using 3% sodium

hydroxide, and then the viscosity was tested immediately.

Determination of viscosity is as following.

Put the viscometer on the platform and set zero after adjusting level using level bar. Repeat

switching to verify whether the zero position was correct;

The measuring device of viscometer was connected to the thermal insulation device, i.e. 501

type digital super constant temperature water bathing kettle. The temperature of water bathing

kettle was set to 97 °C;

Open the circulating pump switch of the constant temperature water bathing kettle connected

with the measuring device of viscometer for preheating 3 minutes;

Pour a certain amount of size mixture obtained above into the measuring device. Move the

rotary drum up and down within a narrow range when pouring the size. After carefully

removing the bubble on the liquid surface of the measuring device, open the switch of the

viscometer;

When the rotary drum rotated stably, move the measuring device carefully to make the rotary

drum gradually approaching the center of the measuring device. Take a reading immediately

after the pointer was stable. Conduct the test three times and took the average.

Results and Discussion

Test Results of Viscosity for 8% Starch Milk. The acidolysis and size mixture blending was carried

out with 8% starch milk, and its viscosity was measured immediately as shown in Fig. 1.

0 1 2 3 4 5

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

粘度（mp.s）

反应时间（h）

6% 盐酸 0.5g 6% 盐酸 0.8g 6% 盐酸 1g 6% 盐酸 1.2g 6% 盐酸 2g

Fig. 1 Effects of different time and HCL dosage on viscosity of 8% starch milk

Fig. 1 shows that the effect of the quantity of hydrochloric acid on the size viscosity is very large

and sensitive. But the viscosity value only reaches to 78mpa·s when 0.5g hydrochloric acid is added,

which is almost the same as the viscosity of the raw starch size, and hardly changes with time, i.e. the

Reaction time(h)

Vis

cosi

ty(m

pa·

s)

6% HCL 0.5g

6% HCL 0.8g

6% HCL 1g

6% HCL 1.2g

6% HCL 2g

Advanced Materials Research Vols. 821-822 1123

hydrochloric acid has not work at this time. When 0.8g hydrochloric acid is added, the viscosity value

is higher in the initial reaction time of 1h, and then declines rapidly. When the hydrochloric acid

added is 1.2g~2g, the viscosity value changes slightly as the reaction time increases. But the viscosity

of textile size cannot be too low, so the quantity of hydrochloric acid added is about 0.8g~1.2g in the

subsequent experiments. On the other hand, it can be seen from Fig. 1, the greater the amount of

hydrochloric acid, the less the reaction time required for the stable size viscosity. In general, after

the reaction time of three hours, the viscosity value almost remains stable.

Test Results of Viscosity for 10% Starch Milk. After 10% starch milk was processed with

acidolysis and size mixture was blended, its viscosity measured immediately was shown in Fig. 2.

0 1 2 3 4 5

5

10

15

20

25

30

35

40

45

50

55

60

65

70

粘度

（mp.s）

反应时间（h）

6% 盐酸 0.85g 6% 盐酸 0.9g 6% 盐酸 1g 6% 盐酸 1.2g 6% 盐酸 1.25g

Fig. 2 Effects of different time and HCL dosage on viscosity of 10% starch milk

Fig. 2 shows that the viscosity value of size mixture decreased gradually with the increase of

hydrochloric acid dosage, and decreased slowly after reaction time of 2h. The results are consistent

with that of 8% starch milk. The viscosity of size mixture which was added in 0.85g~1g hydrochloric

acid decreased slightly in 2h~3h, and is always maintained at 30mpa·s~40mpa·s after 3h. When the

hydrochloric acid dosage was increased to more than 1.2g, the viscosity almost remained unchanged

after 2h, namely the viscosity has been stable and maintained at 20mpa·s~25mpa·s. Therefore, if 10%

starch milk was used to make acidolysis and size mixture blended, the reaction time can be shortened

to 2h while adding 1.2g~1.25g hydrochloric acid of 6%, and 3h reaction time is appropriate while

adding 0.85g~1g hydrochloric acid.

Test Results of Viscosity for 12% Starch Milk. After 12% starch milk was processed with

acidolysis and size mixture was blended, its viscosity measured immediately was shown in Fig. 3.

As can be seen from Fig. 3, it is similar to the results for two above concentrations of starch milk,

the viscosity of size mixture added different dosage of hydrochloric acid decreases significantly

before reaction time 2h, and then decreases slowly. The viscosity decreases greatly when the

hydrochloric acid dosage increases from 0.8g to 1g. Seen from the stable viscosity, the viscosity value

decreases approximately from 50mpa·s to 25mpa·s. The viscosity change is relatively small when the

hydrochloric acid dosage increases from 1g to 2g, and the change value is around within 10mpa·s.

Therefore, if 12% starch milk was used to make acidolysis and size mixture blended, it is difficult to

control the size viscosity value when adding 0.8g~1g hydrochloric acid of 6%, and the effect of

hydrochloric acid dosage on viscosity is significant. When the dosage of hydrochloric acid is

1g~1.2g, the size viscosity value is in the error tolerance range, and the reaction time can be shortened

to 2h.

6% HCL 0.85g

6% HCL 0.9g

6% HCL 1g

6% HCL 1.2g

6% HCL 1.25g

Reaction time(h)

Vis

cosi

ty(m

pa·

s)

1124 Advances in Textile Engineering and Materials III

Fig. 3 Effects of different time and HCL dosage on viscosity of 12% starch milk

Effect of One-step process on Thermal Stability of Size Viscosity. The thermal stability of size

viscosity directly affects the sizing quality indexes, such as sizing percentage. During the

determination of the thermal stability of viscosity, if the structural viscosity changes very small or

changes very quickly under the action of shear stress, then the thermal stability of viscosity is

good[4].

Taking 12% starch milk as an example, the viscosity measured immediately after 2h of the

reaction time was compared with that measured after size mixture stored 1h in 97 °C water bath kettle

followed by reaction time 2h. The results of thermal stability were shown in Table 1.

Table 1 Thermal stability of size mixture for 12% starch milk

Hydrochloric acid(g) 0.8 0.9 1 1.2

Viscosity measured immediately(mpa·s) 55 41 30 18

Viscosity measured after thermal insulation for 1h(mpa·s) 50 38 28 17

As can be seen from Table 1, the viscosity of size mixture got from one-process decreased slightly

after thermal insulation for 1h, but remains at about 5mpa·s. It indicates that the thermal stability of

viscosity is good.

Conclusions

When the concentration of cassava starch milk is in the range of 8%~12%, the dosage of 6%

hydrochloric acid using for acidolysis catalyst is about 0.8g~1.2g;

The viscosity of acidolysis starch decreases with the increase of hydrochloric acid dosage, and

the stable viscosity is about in the range of 15mpa·s~55mpa·s;

For the low viscosity (15mpa·s~25mpa·s) size, the viscosity can be stabilized in a short time,

generally around 2h;

For the high viscosity (25mpa·s~55mpa·s) size, the viscosity can be stabilized in relatively long

time, generally around 3h;

The thermal stability of size viscosity obtained in one-process is good.

References

[1] Y. J. Wang, V. D. Truong, L. Wang: Carbohydrate Polymers, Vol.52 (2003), p.327

[2] J. F. Shen, etc.: Journal of Zhejiang Agricultural University, Vol. 23(1997), p.297 (In Chinese)

[3] G. F. Yao, etc.: Shanghai Textile Science & Technology, Vol. 31(2003), p.20 (In Chinese)

[4] X. R. Fan, etc.: Cotton Textile Technology, Vol. 26(1998), p.19 (In Chinese)

Vis

cosi

ty(m

pa·

s)

Reaction time(h)

Advanced Materials Research Vols. 821-822 1125

Advances in Textile Engineering and Materials III 10.4028/www.scientific.net/AMR.821-822 Study on One-Step Process of the Size Mixture Blending and Acidolysis Modification of Starch 10.4028/www.scientific.net/AMR.821-822.1122

DOI References

[1] Y. J. Wang, V. D. Truong, L. Wang: Carbohydrate Polymers, Vol. 52 (2003), p.327.

http://dx.doi.org/10.1016/S0144-8617(02)00323-5