The principle of capillary viscometer

A viscometer based on Hagen Poisson's (Hagen-Poisculli) rule is obtained by measuring the flow rate of fluid flowing through the capillary, the pressure difference between the capillary outlet and the inlet, and then according to Hagen Poisson's law.

Capillary viscometer

A viscometer based on Hagen Poisson's (Hagen-Poisculli) rule is obtained by measuring the flow rate of fluid flowing through the capillary, the pressure difference between the capillary outlet and the inlet, and then according to Hagen Poisson's law.

Hagen - bershaw leaf formula:

ETA = (n R^4Pt) /8VL

Among them:

V--t time flows through the capillary volume

R-- capillary radius

P-- capillary pressure difference at the end of two

L-- capillary length

As long as the volume, time and pressure added to the liquid are obtained, the viscosity of the liquid can be reversed.

There are three main types of capillary viscometer: round - piston, glass tube and pass viscometer. The circular hole - piston viscometer allows for greater pressure, so it can be used to determine the viscosity of the polymer.

The pore type viscometer is also called the short tube type, and the small pore type can be used for rough measurement and viscosity comparison of Newtonian fluid. Glass tube type viscosity and wide application, can be divided into gravity type and pressure type. The gravity type is generally used to measure the Newton fluid, and the pressure type can be used to measure the non Newton fluid. There are many kinds of glass capillary viscometer, most of which are named by the designer's name abroad. The methods of their construction and use are all the same.

Polylactic acid PLA molecular weight and intrinsic viscosity

Polylactic acid, also known as polylactide, belongs to the polyester family. Polylactic acid is a polymer obtained by polymerization of lactic acid as a main raw material, and the raw materials are abundant and can be regenerated. Polylactic acid production process pollution-free, but also biodegradable products to achieve in the nature of the cycle, it is the ideal green polymer materials.

Polylactic acid (H- [OCHCH3CO] n-OH) thermal stability, processing temperature 170 ~ 230 ℃, good solvent resistance, can be processed by a variety of ways, such as extrusion, spinning, biaxial stretching , Injection blow molding. In addition to biodegradable products made of polylactic acid, biocompatibility, gloss, transparency, feel and heat resistance, polylactic acid (PLA) developed by Brilliance Albert also has some antibacterial, flame retardant It is used in a wide range of applications as packaging materials, fibers and nonwovens. It is mainly used in garments (underwear, garments), industry (construction, agriculture, forestry, paper making) and healthcare.

PLA molecular weight and viscosity (experimental results for reference only)

① Mn = 55872η1.2967 → η = 2.18 × 10-4Mη0.77

② Mw = 264911η1.7519 → η = 8.03 × 10-4 Mw0.57

③ Mn = 126911η1.6982 → η = 9.88 × 10-4Mn0.59

④ Mz = 472515η1.7836 → η = 6.59 × 10-4Mz0.56

⑤Mz + 1 = 670038η1.7453 → η = 4.59 × 10-4 Mz + 10.57

Where: η is the viscosity;

Mη is the viscosity average molecular weight;

Mw is the weight average molecular weight;

Mn is the number average molecular weight;

Mz is Z average molecular weight;

Mz + 1 is the Z + 1 average molecular weight.

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD. Skype: kenyuan9023   Wechat/WhatsApp:+86 15068109723E lei@zonwon.com  W www.zonwontech.com

Determination Intrinsic Viscosity of ACR

Determination Intrinsic Viscosity of ACR

First, equipment and auxiliary equipment

① Φ0.56mm a Ukrainian viscometer

② a set of automatic viscometer (25 ℃ ± 0.01 ℃)

③ 3 # sand core funnel 3 (covered)

④ conical flask 3

⑤ 75ml volumetric flask 3

Second, reagents: analytical grade (chloroform), content ≥ 99.0%

Third, the intrinsic viscosity of the sample test: 1, configuration solution 2, measured viscosity

1, configure the solution

① measuring bottle logo: the required capacity of 75ml three bottles (should be kept dry) clearly identified by the number.

Note: High viscosity is used separately from the volumetric flask used for low viscosity samples.

② balance calibration: Calibrate the balance, adjust the level (adjust the bottom of the balance knob so bubbles in the middle of the circle), with 200 grams weight calibration;

When adjusting the balance, or weighing, you should close the doors, windows, etc., at the same time shut down the balance door to prevent the wind from affecting the balance. When weighing, the balance can be read after the number of stable, prohibit the balance of data beating larger than reading.

 '¢ with liquid: open in Wang automatic dosing device DP25 and the DP25 and electronic scales connected to the sample bottle into the electronic balance and add 0.075g ± 0.01 ɡ expected in the automatic dial-up device DP25 touch screen settings The required concentration of 0.003g / ml, click the dosing button to complete dosing.

④ Sample Dissolution: Place the sample bottle containing the concentration solution in P12, and set the sample-dissolving time. The sample is dissolved automatically by P12.

2, Viscosity Testing:

① open the viscosity of the instrument set sink temperature 25 ℃ (Chung Mong Intelligent Viscosity Measurement System IVS300 series temperature control accuracy of ± 0.01 ℃), to be stable after the temperature field into the chloroform solvent with Ubbelohde viscometer (with basket) Click the start test, the system will automatically complete the continuous test and remove the unqualified data, get T0; the same way to measure the sample solution Flow time t.

② measure the t value of other bottles: the same way to measure the viscosity of the remaining two samples (tools can not be mixed).

③ by the viscosity of the software obtained in the sample viscosity of the sample solution.

Fourth, tool cleaning:

① Ubbelohde viscometer after use, the amount of chloroform 50ml beaker to take 25ml of chloroform added to the viscometer, use the ear wash up, then blow down, repeated three times (Note viscometer is not allowed to use water scouring, if water enters Should be dry), Ubbelohde viscometer upside down in the folder after the clip on the butterfly.

② volumetric flask and sand funnel were washed, with a 50ml beaker to take 25ml of chloroform into the volumetric flask, and then repeatedly shaken several times; sand funnel also 25ml chloroform wash shampoo, then wash the ear ball from the mouth Blowing out the waste a few times; Erlenmeyer flask with chloroform.

Note: All waste liquid into the waste collection bottle, warehousing unified treatment, after cleaning, measuring flask, sand funnel inverted placed in the tool plate, rack.