ASTM D1795-2013 Standard Test Method for Intrinsic Viscosity of Cellulose《纤维素固有粘度的标准试验方法》.pdf
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1、Designation: D1795 13Standard Test Method forIntrinsic Viscosity of Cellulose1This standard is issued under the fixed designation D1795; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenth
2、eses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the intrin-sic viscosity of purified celluloses such as bleached woodpulps, cotton linters, and regenerated
3、 cellulose. It is applicableto all cellulose samples with an intrinsic viscosity of 15 dl/g orless. Most native (unpurified) celluloses have intrinsic viscos-ity values too high for measurement by this test method.NOTE 1The use of cuprammonium hydroxide solution for regularviscosity determination is
4、 described in Method T 206 m-55 of theTechnical Association of Pulp and Paper Industry on “CuprammoniumDisperse Viscosity of Pulp,” and Joint Army-Navy Specifications JAN-C-206.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard
5、.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced
6、Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D629 Test Methods for Quantitative Analysis of TextilesE1 Specification for ASTM Liquid-in-Glass ThermometersE2251 Specification for Liquid-in-Glass ASTM Ther
7、mom-eters with Low-Hazard Precision Liquids3. Summary of Test Method3.1 Aweighed sample of the material is dissolved in a 0.5 Mcupriethylenediamine hydroxide solution. The viscosity of thissolution, and also that of the solvent, is determined at 25C bymeans of a calibrated glass capillary-type visco
8、meter. Therelative viscosity is calculated and the corresponding intrinsicviscosity is read from a table.4. Significance and Use4.1 This test is a sensitive measure of the degradation ofcellulose resulting from the action of heat, light, acids, alkalies,oxidizing and reducing agents, and the like, u
9、sed in itsprocessing or purification. The intrinsic viscosity value may beconverted to degree of polymerization (DP) or to intrinsicfluidity, if desired.4.2 Solutions of cellulose are not Newtonian liquids; that is,their viscosity depends upon the rate-of-shear or velocitygradient during measurement
10、.This effect is smaller for samplesof low molecular mass (DP) and at low concentrations than forhigh-DP samples and at high concentrations. For the cellulosesand concentrations included within the limits set forth in thistest method, the effect of rate-of-shear is assumed to benegligible for referee
11、 purposes. For other conditions and forresearch purposes this assumption may be invalid, but todiscuss ways of accounting for this effect is beyond the scopeof the present test method.5. Apparatus5.1 Viscometer, Glass, Capillary TypeThe Cannon-Fenske, Ubbelohde, or similar capillary type instrument
12、asdescribed in Test Method D445 is recommended. In order toavoid correction for the kinetic energy effect, choose a viscom-eter with a small enough capillary to give an outflow time of 80s or more for the Cannon-Fenske type. (A size 100 viscometeris normally used for the sample solution and a size 5
13、0 for thesolvent.)5.2 ThermometerASTM Kinematic Viscosity Thermom-eter for use at 25C, having a range from 19 to 27C andconforming to the requirement for Thermometer 17C asprescribed in Specification E1. Thermometric devices such asRTDs, thermistors and liquid-in-glass thermometers (as speci-fied in
14、 Specification E2251) of equal or better accuracy in thespecified temperature range, may be used.5.3 BathA constant-temperature bath at 25C suitable forimmersion of the viscometer so that the reservoir or the top ofthe capillary, whichever is uppermost, is immersed at least 501This test method is un
15、der the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved June 1, 2013. Published July 2013. Originally approvedin 1960. Last previous edi
16、tion approved in 2007 as D1795 96 (2007)1. DOI:10.1520/D1795-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM websi
17、te.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1mm, and with provision for visibility of the instrument and thethermometer. Firm supports for the viscometer shall be pro-vided; or the viscometer may be sealed in as an integral part
18、 ofthe bath. Either a liquid bath with thermostatic regulation anda stirrer or a vapor bath with pressure regulation is permissible.The efficiency of the stirring and the balance between heatlosses and heat input must be such that the temperature of thebath medium does not vary by more than 60.1C ov
19、er thelength of the viscometer, or from viscometer to viscometer inthe various bath positions. If a vapor bath is used, there mustbe no temperature gradient over the length of the viscometergreater than that permitted in a liquid bath.5.4 TimerA stop watch or other spring-activated timingdevice or e
20、lectrical timing device shall be used, graduated indivisions of 0.2 s or less, and accurate to within 0.05 % whentested over not less than a 10-min period. Such electricaltiming devices shall be used only on electrical circuits ofcontinuously controlled frequency. Frequency-controlled de-vices of su
21、itable capacity for laboratory purposes, accurate towithin 1 part in 10 000 should be used. Errors exceeding0.05 % of a 10-min interval may occur in timing devicesactuated by electrical synchronous motors driven by mostpublic power systems, which are intermittently and not con-tinuously controlled.6
22、. Reagent6.1 Cupriethylenediamine Hydroxide Solution (1.00 6 0.01M), in copper, with the molar ratio of ethylenediamine tocopper of 2 6 0.1 to 1. This solvent may be prepared in thelaboratory. It is also commercially available.37. Reference Materials7.1 Viscosity Oil StandardsCalibrating oils in the
23、 speci-fied ranges of viscosity.3Aqueous solutions of glycerol may beused instead of standardized oils; the compositions for variousviscosities are given in chemical handbooks. The applicableviscosity oil standards (Note 2) are listed in Table 1.NOTE 2The viscosity oil standards are available only a
24、s 4.7- m3(1-pt)samples. More than 1 pt of any given oil (for example, duplicate samples)are supplied only when it is established that 1 pt is inadequate.38. Calibration of Viscometer8.1 The following directions apply to the Cannon-Fenskeviscometer (Note 3). They should be modified according to theop
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