GB/T 22905-2008Superabsorbent polymer for diaper (English PDF)

Foreword

Annex A, Annex B, Annex C, Annex D, Annex E, Annex F, Annex G of this

Standard are normative.

This Standard was proposed by China Light Industry Federation.

This Standard shall be under the jurisdiction of National Technical Committee

on Paper Industry of Standardization Administration of China.

Main drafting organizations of this Standard. China Pulp and Paper Research

Institute, Jinan Haoyue Suction Material Co., Ltd., National Paper Quality

Supervision and Inspection Center.

The drafting organizations of this Standard. Sanda Fine Chemicals (Nantong)

Co., Ltd., BASF (China) Investment Co., Ltd., Formosa Plastics Resin (Ningbo)

Co., Ltd., Kimberly (China) Co., Ltd., Guangzhou P&G Co., Ltd., Fujian Hengan

Group Co., Ltd., Evonik Degussa (China) Investment Co., Ltd., Kao (China)

Investment Co., Ltd., Ritong Chemical (Zhangjiagang) Co., Ltd., Quanzhou

Banglida Technology Industrial Co., Ltd., You Nijia Daily Necessities (China)

Co., Ltd.

Main drafters of this Standard. Gao Jun, Yang Zhiliang, Zhou Junfeng.

Superabsorbent polymer for diaper

1 Scope

This Standard specifies the requirements, test methods, inspection rules and

marks, packaging, transport, storage for superabsorbent polymer of

polyacrylate for diaper.

This Standard is applicable to superabsorbent polymer of polyacrylate for all

kinds of baby diapers (pieces), adult incontinence products.

2 Requirements

3 Test methods

4 Inspection rules

5 Marks, packaging, transport, storage

200 mL of saline of which the concentration is 0.9% (A.1.10). Put it back into

the rotor and cover it. Use the magnetic stirrer (A.1.2) to stir 1h. Use filter paper

(A.1.3) to filter. Use the filtrate as test solution.

A.2.2 Standard curve

Determine the peak area of the acrylic acid solution with a known concentration.

Draw a standard curve with the acrylic acid concentration as the abscissa and

the peak area as the ordinate.

A.2.3 Specimen determination

Use the micro syringe (A.1.7) to inject the testing solution into the high

performance liquid chromatography (A.1.4) through the filter membrane filter

(A.1.8). Determine according to the following conditions. Calculate the peak

area.

Conditions for determination.

Mobile phase. 0.1% H3PO4 aqueous solution;

Flow. 1.0mL/min ~ 2.0mL/min;

Injection volume. 20µL ~ 100µL;

UV detector (A.1.5). detection wavelength is 210nm.

A.3 Representation of results

According to the peak area and standard curve of the testing solution, calculate

the residual monomer (acrylic acid) content in the specimen according to

formula (A.1), to the nearest of the first place after the decimal point.

Where,

X - Residual monomer (acrylic acid) content, in milligrams per kilogram (mg/kg);

c - Acetic acid concentration obtained from the standard curve, in milligrams per

liter (mg/L);

m - Mass of weighed specimen, in grams (g).

Annex B

(normative)

Determination of volatile matter content

B.1 Apparatus and reagents

B.1.1 Oven, which can keep the temperature at 105°C ± 2°C.

B.1.2 Dryer.

B.1.3 Electronic balance, with a resolution of 0.001g.

B.1.4 Specimen container, for specimen transfer and weighing. This container

is made of a lightweight material that is water-resistant and resistant to changes

under test conditions.

B.2 Measuring steps

B.2.1 Weigh 5 g of specimen, to the nearest of 0.001 g. Load into the container

(B.1.4) with a constant weight. Place the container that has contained the

specimen into the (105±2)°C oven (B.1.1), drying for 4h. And open the lid of the

weighing container and dry it together. When the drying is finished, the lid of the

container shall be covered in the oven. Then move into the dryer (B.1.2) to cool.

Weigh the container and the specimen mass after 30 min.

B.2.2 Repeat the above steps by moving the weighing container into the oven

again. Drying time between two consecutive weighings shall be no less than 1h.

When the difference between two consecutive weighings is not more than 0.2%

of the original mass of the specimen, it can be determined that the specimen

reaches a constant weight.

B.3 Representation of results

B.3.1 Calculation of volatile matter content

The volatile matter content can be calculated according to formula (B.1).

Where,

X - Volatile matter content, %;

m1 - Mass of specimen before drying, in grams (g);

m2 - Mass of specimen after drying, in grams (g).

B.3.2 Representation of results

Simultaneously perform two measurements. Take the arithmetic mean as the

measurement result, and round up to the integer position. The error between

the two measurements shall not exceed 0.2% (absolute value).

Annex C

(normative)

Determination of pH

C.1 Apparatus and reagents

C.1.1 Electronic balance, with a resolution of 0.001g.

C.1.2 Measuring cylinder, with a resolution of 100mL.

C.1.3 Magnetic stirrer.

C.1.4 pH meter.

C.1.5 Saline, with a concentration of 0.9%.

C.2 Measuring steps

C.2.1 Use measuring cylinder (C.1.2) to accurately measure 100 mL of saline

(C.1.5). Pour into a 150mL beaker. And place on the magnetic stirrer (C.1.3) for

moderate stirring. Avoid bubbles in the solution during the mixing process.

C.2.2 Use the electronic balance (C.1.1) to weigh 0.5 g of specimen, to the

nearest of 0.001 g. Slowly add the weighed specimen into the beaker. After

moderate stirring for 10 min, remove the beaker from the magnetic stirrer and

stop stirring. Place still for 8 min so as to precipitate suspended resin.

C.2.3 According to the instrument instructions, use buffer solution to adjust pH

meter (C.1.4). The pH composite electrode is then slowly inserted into the

solution above the precipitated specimen. Read the pH meter value after 2 min.

In order to prevent contamination of the electrode, the electrode shall not touch

the specimen. After reading the indication, remove the electrode and rinse

thoroughly with deionized water, then immerse it in the electrode protection

buffer solution.

C.3 Representation of measurement results

The measurement results are read directly from the pH meter. Simultaneously

perform the two measurements. Take the average of two measurements as the

measurement result. The result is rounded to one decimal place.

Annex D

(normative)

Determination of particle size distribution

D.1 Apparatus and reagents

D.1.1 Electronic balance, with a resolution of 0.01g.

D.1.2 Screen vibrator, with an amplitude of 1mm, with a frequency of 1400r/min.

D.1.3 Screen, using standard sieves with mesh sizes of 45µm and 106µm.

D.1.4 Receiving base plate and cover.

D.1.5 Brush.

D.2 Measuring steps

D.2.1 Clean the screen (D.1.3) before each use. Check the entire surface of the

screen under the light source. Check the damage of each screen. If any cracks

or holes are found, discard the damaged screen and replace it with a new one.

If the screen is not clean, it needs to be cleaned.

D.2.2 Lay the screen on the screen vibrator (D.1.2). Place the receiving base

plate (D.1.4) at the bottom. Stack the sieves from top to bottom in the order of

106µm to 45µm. Weigh 100g of specimen with a 250mL glass beaker, to the

nearest of 0.01g. Pour the specimen gently into the top of the sieve. Cover with

the cover (D.1.4) and start the screen vibrator to vibrate for 10min. Then

carefully remove the screen. Weigh the 45µm screen and the mass of the

specimen on the receiving base plate. Ventilation airflow shall be avoided

during the measurement. Use the brush (D.1.5) to collect the lower part of the

sieve into the waste dish and clean the screen.

D.3 Representation of measurement results

The particle size distribution can be calculated according to formula (D.1) and

formula (D.2).

Where,

X1 - Content below 106µm, %;

X2 - Content below 45µm, %;

m1 - Total mass of specimen, in grams;

m2 - The mass of the specimen remaining on the 45µm sieve, in grams (g);

m3 - The mass of the specimen remaining on the receiving base plate, in grams

(g).

Simultaneously perform the two measurements. Take the arithmetic mean as

the measurement result, the result is rounded to one decimal place.

Annex E

(normative)

Determination of density

E.1 Apparatus and reagents

E.1.1 Densitometer.

E.1.2 Funnel, with a capacity greater than 120mL, with perforated throttling

damping or baffle, inner diameter of the orifice 10.00mm ± 0.01mm.

E.1.3 Density cup, with a cup capacity of 100cm3±0.5cm3.

E.1.4 Electronic balance, with a resolution of 0.01g.

E.2 Measuring steps

E.2.1 Place the densitometer (E.1.1) on the platform. Adjust the screws on the

three feet to keep them horizontal. Place the washed and dried funnel (E.1.2)

vertically at a height of 40mm ± 1mm above the center of the density cup (E.1.3)

to ensure the funnel level. Weigh the mass of the empty density cup m1, to the

nearest of 0.01g. Then place the weighed empty density cup directly below the

funnel.

E.2.2 Weigh about 120g of specimen and gently add it to the funnel. The orifice

throttling damping or baffle under the funnel is closed. Quickly open the orifice

throttling damping or baffle under the funnel to allow the specimen inside the

funnel to fall naturally. Use a glass rod to scrape off the excess specimen on

the top of the density cup. Do not tap or shake the density cup. Weigh the mass

of the density cup that contains the specimen m2, to the nearest of 0.01g.

E.3 Representation of measurement results

The density can be calculated according to formula (E.1).

Where,

rho - The density, in grams per cubic centimeter (g/cm3);

m1 - The mass of the empty density cup, in grams (g);

m2 - The mass of the density cup that contains the specimen, in grams;

V - The volume of the density cup, in cubic centimeter (cm3).

Simultaneously perform the two measurements. Take the arithmetic mean as

the measurement result, the result is rounded to one decimal place.

Annex F

(normative)

Determinations of absorption and water retention

F.1 Apparatus and reagents

F.1.1 Electronic balance, with a resolution of 0.001g.

F.1.2 Paper tea bag, with a size of 60mm × 85mm, a gas permeability of

(230±50) L/(min·100cm2) (pressure difference of 124Pa).

F.1.3 Clip, for fixing the tea bag.

F.1.4 Centrifugal dewatering machine, with a diameter of 200mm and a speed

of 1500 r/min (which can generate a centrifugal force of about 250g).

F.1.5 Saline, with a concentration of 0.9%.

F.2 Measuring steps

F.2.1 Determination of absorption

F.2.1.1 Weigh 0.2g of specimen, to the nearest of 0.001g. Record this mass as

m. Pour this specimen into the bottom of the tea bag (F.1.2). The specimen

attached to the inside of the tea bag shall also be poured into the bottom of the

tea bag.

F.2.1.2 Seal the tea bag. Soak in a beaker containing a sufficient amount of 0.9%

saline (F.1.5). The soaking time is 30min.

F.2.1.3 Gently pour out the tea bag that contains the specimen. Use the clip

(F.1.3) to hang up. Drip water at rest for 10 min. When multiple tea bags are

hung at the same time, note that the tea bags shall not touch each other.

F.2.1.4 After 10 minutes, weigh the mass of the tea bag that contains the

specimen m1.

F.2.1.5 Use the tea bag that does not have the specimen for the determination

of blank value. Weigh the mass of the tea bag of the blank test. Record this

mass as m2.

F.2.2 Determination of water retention

F.2.2.1 Perform the centrifugal dewatering the tea bag that contains the

specimen and the absorption amount has been measured for 3min under the

condition of 250 g of centrifugal force (see F.1.4).

F.2.2.2 After the dewatering finishes in 3min, weigh the mass of the tea bag that

contains the specimen. Record this mass as m3.

F.2.2.3 Use the tea bag that does not have the specimen to perform the

determination of blank value, simultaneously. Weigh the mass of the tea bag

for the blank test and record this mass as m4.

F.3 Representation of measurement results

The absorption and water retention amounts can be calculated according to

formula (F.1) and formula (F.2).

Where,

c1 - The absorption amount, in grams per gram (g/g);

c2 - The water retention amount, in grams per gram (g/g);

m - The mass of the weighed specimen, in grams (g);

m1 - The mass of the tea bag that contains the specimen, in grams (g);

m2 - The mass of the tea bag for the blank test, in grams (g);

m3 - The mass of the tea bag that contains the specimen after dewatering, in

grams (g);

m4 - The mass of the tea bag for the blank test after dewatering, in grams (g).

Simultaneously perform the two measurements. Take the arithmetic mean as

the measurement result, the result is rounded to one decimal place.

Annex G

(normative)

Determination of pressure absorption

G.1 Apparatus and reagents

G.1.1 Plastic drum with an inner diameter of 25mm, an outer diameter of 31mm,

a height of 32mm, and a 50µm nylon mesh on the bottom surface.

G.1.2 Plastic piston stuck with weight (2068Pa), drum type, with an outer

diameter of 25 mm, can be tightly connected with plastic drum (G.1.1), and can

move up and down freely.

G.1.3 Electronic balance, with a resolution of 0.001g.

G.1.4 Shallow base plate, with an inner diameter of 85mm, a height of 20mm,

and stuck with a metal wire with a diameter of 2mm, as shown in Figure G.1.

Figure G.1

G.1.5 Saline, with a concentration of 0.9%.

G.2 Measuring steps

G.2.1 The measurement shall be carried out at (23±2)°C.

G.2.2 Add 25g of standard physiological saline at a temperature of (23±2)°C to

the shallow base plate (G.1.4). Place this plate on the platform.

G.2.3 Weigh 0.160 g of specimen m1, to the nearest of 0.001 g. Load into the

plastic drum (G.1.1).

G.2.4 Place the plastic piston stuck with weight (G.1.2) into the plastic drum

that has loaded with testing specimen (G.1.1). Weigh its mass m2.

Plastic drum Below plastic drum Plastic drum weight

and plastic piston

Shallow base plate

Metal

G.2.5 Place the plastic drum that has loaded with testing specimen in the center

of the shallow base plate.

G.2.6 After 60min, lift the plastic drum out of the shallow base plate. Weigh the

mass of this drum m3.

G.3 Representation of measurement results

The pressure absorption amount can be calculated according to formula (G.1).

Where,

c - The pressure absorption amount, in grams per gram (g/g);

m1 - The mass of the weighed specimen, in grams (g);

m2 - The mass of plastic piston and plastic drum, in grams (g);

m3 - The mass of the plastic drum, plastic piston and specimen after pressure

absorption, in grams (g).

Simultaneously perform the two measurements. Take the arithmetic mean as

the measurement result, the result is rounded to one decimal place.

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