1、 ISO 2014 Plastics Thermoplastic polyurethanes for moulding and extrusion Part 3: Distinction between ether and ester polyurethanes by determination of the ester group content Plastiques Polyurthannes thermoplastiques pour moulage et extrusion Partie 3: Distinction entre polyurthannes ther et ester
2、par dosage des groupements esters INTERNATIONAL STANDARD ISO 16365-3 First edition 2014-05-01 Reference number ISO 16365-3:2014(E) ISO 16365-3:2014(E)ii ISO 2014 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2014 All rights reserved. Unless otherwise specified, no part of this publication may
3、 be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the
4、requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO 16365-3:2014(E) ISO 2014 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative refere
5、nces 1 3 T erms and definitions . 1 4 Principle 2 5 Reagents 2 6 Apparatus . 2 7 Sample preparation . 3 8 Procedure. 3 9 Calculation 3 10 Report 4 Bibliography 5 ISO 16365-3:2014(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodi
6、es (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations
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9、 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introd
10、uction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to c
11、onformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic materials.
12、 ISO 16365 consists of the following parts, under the general title Plastics Thermoplastic polyurethanes for moulding and extrusion: Part 1: Designation system and basis for specifications Part 2: Preparation of test specimens and determination of properties Part 3: Distinction between ether and est
13、er polyurethanes by determination of the ester group contentiv ISO 2014 All rights reserved ISO 16365-3:2014(E) Introduction The saponification value is a fast and easy determination method to distinguish between polyesterol and polyetherol-based thermoplastic polyurethanes. However, the saponificat
14、ion value strongly depends on the reaction conditions. Higher saponification values result in longer hydroxylation times and/or higher temperatures. With this procedure, the theoretically expected values have been found. ISO 2014 All rights reserved v Plastics Thermoplastic polyurethanes for mouldin
15、g and extrusion Part 3: Distinction between ether and ester polyurethanes by determination of the ester group content 1 Scope This part of ISO 16365 specifies a method for the determination of esters including ester thermoplastic polyurethanes (TPU) and ether TPU for quality control without the nece
16、ssity of sophisticated instrumentation and avoids or minimizes long-term microbial testing for TPU materials. The method described is used to distinguish major TPU types and characterize TPU mixtures. The method is applicable to all linear polyurethanes based on 4,4-diphenylmethane diisocyanate (MDI
17、) and is intended for instance to minimize long-term tests related to microbe resistance and hydrolysis. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition
18、cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3696, Water for analytical laboratory use Specification and test methods 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions appl
19、y. 3.1 acid value of total hydrolysable groups S Z1 number of milligrams of potassium hydroxide required to neutralize the free acids of ester and urethane groups present in 1 g of thermoplastic polyurethanes, when determined in accordance with the procedure specified in this part of ISO 16365 Note
20、1 to entry: The acid value is expressed in milligrams per gram. 3.2 acid value of hydrolysable urethanes S Z2 number of milligrams of potassium hydroxide required to neutralize the free acids of only urethane groups present in 1 g of thermoplastic polyurethanes, when determined in accordance with th
21、e procedure specified in this part of ISO 16365 Note 1 to entry: The acid value is expressed in milligrams per gram. INTERNATIONAL ST ANDARD ISO 16365-3:2014(E) ISO 2014 All rights reserved 1 ISO 16365-3:2014(E) 3.3 ester content E number of milligrams of potassium hydroxide required to neutralize t
22、he free acids of only ester groups present in 1 g of thermoplastic polyurethanes, when determined in accordance with the procedure specified in this part of ISO 16365 Note 1 to entry: The ester content is expressed in milligrams per gram. 4 Principle The content of ester groups in TPU is determined
23、by alkaline hydrolysis. The amount of urethane groups is determined and subtracted from the determined total amount of hydrolysable compounds, i.e. esters and urethanes. The difference is a measure of the content of ester groups in mg KOH/g. Pure polyether- TPU yields results close to 0 mg KOH/g. 5
24、Reagents During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 5.1 Dimethylsulfoxide. 5.2 Potassium hydroxide solution, c(KOH) = 0,5 mol/l accurate to 0,001 mol/l, methanol solution. 5.3 Sulfuric acid, c(H 2 SO 4 ) = 0,5 mol/l a
25、ccurate to 0,001 mol/l, aqueous solution. 5.4 Phenolphtaleine, 1 % in methanol or ethanol. 5.5 Methanol, for analysis. 5.6 Water, distilled or of equivalent purity in accordance with ISO 3696. 6 Apparatus 6.1 Centrifugal mill, with sieve of 2 mm. 6.2 Analytical balance, accuracy 0,1 mg or better. 6.
26、3 Er lenm e y er flask, with capacity of 250 ml which can be closed. 6.4 Automatic burette, with capacity of 20 ml or similar. 6.5 Magnetic stirrer, with heater. 6.6 R eflux c ooler, with polytetrafluoroethylene (PTFE) manchette. 6.7 Magnetic stirrer, 40 mm. 6.8 Volumetric measuring cylinder, 50 ml.
27、 6.9 Soxhlet apparatus.2 ISO 2014 All rights reserved ISO 16365-3:2014(E) 7 Sample preparation Cut a representative fraction of the sample to be analysed into pieces of approximately 2 mm in diameter. For thermoplastic urethane materials containing phosphorous plasticizers, extract 3 g of the powder
28、ed sample for 4 h in methanol using a Soxhlet extractor (see 6.9). Remove the sample from the extractor and dry for 30 min at 60 C in an oven. NOTE Phosphorous esters used as plasticizers for TPU have no influence on the resistance of the material against microbes. However, the presence of phosphoro
29、us ester will cause a higher ester content result. 8 Procedure At least two determinations shall be carried out. Weigh a test portion of 0,5 g to the nearest 1 mg (E gram) into an Erlenmeyer flask of 250 ml (see 6.3). Add 40 ml dimethylsulfoxide (see 5.1) and a magnetic stirrer (see 6.7), close the
30、flask and the stir for 15 min. NOTE The sample may only be partially dissolved after 15 min. Add 20 ml (see 5.2) of a solution of potassium hydroxide (see 5.2) under continuous stirring to avoid coagulation. The sample is hydrolysed for 5 h under reflux conditions and continuous stirring (see 6.6) o
31、n the magnetic stirrer with heater (see 6.5). Two blank determinations are prepared following the same procedure. Cool to room temperature and rinse the reflux cooler and Erlenmeyer wall with 50 ml of water. The surplus amount of KOH is titrated by sulphuric acid (see 5.3) from red to colourless usi
32、ng 10 droplets of phenolphthalein solution as indicator (sample: V 1ml, average blanks; V 1bml) but avoiding an excess of sulphuric acid. After titration add 10 ml of H 2 SO 4(see 5.3) by a burette and boil for 10 min on the magnetic stirred with heater while continuously stirring. It is essential t
33、hat all carbon dioxide is removed from the solution. After cooling to room temperature the surplus amount of sulphuric acid is titrated back by KOH (see 5.2) using phenolphthalein as indicator. The titration is carried out from colourless to slightly pink (sample: V 2ml, average blanks: V 2bml). NOT
34、E 1 Fillers like CaCO 3and other additives such as some flame retardants which may form salts might have an effect on the result. NOTE 2 Pigments may change the visibility of the colour change of the indicator which will make it difficult or impossible to carry out a visual titration. NOTE 3 Potenti
35、ometric titration is also possible. 9 Calculation Calculate the ester content in mg KOH/g as follows: E = S Z1 S Z2 (1) where E is the ester content in mg KOH/g. (2) ISO 2014 All rights reserved 3 ISO 16365-3:2014(E) (3) where S Z1 is the ester + urethane content in mg KOH/g (acid value of total hyd
36、rolysable groups); S Z2 is the urethane content in mg KOH/g (acid value of hydrolysable urethanes); V 1 is the consumption of sulphuric acid in ml; V 1b is the consumption of sulphuric acid in ml (blank value); V 2 is the consumption of 0,5 mol KOH in ml; V 2b is the consumption of 0,5 mol KOH in ml
37、 (blank value); w is the mass of the sample in g; t is the titre/norm factor of sulphuric acid (t = actual concentration/target concentration). 10 Report The report shall include the following information: a) a reference to this part of ISO 16365 (i.e. ISO 16365-3); b) the type and name of the teste
38、d material; c) the ester content in mg KOH/g with specification of the titration process (potentiometric or indicator); d) the acid value of total hydrolysable groups and the acid value of hydrolysable urethanes in mg KOH/g; e) the differences to this part of ISO 16365; f) the date of the test.4 ISO
39、 2014 All rights reserved ISO 16365-3:2014(E) Bibliography 1 ISO 385, Laboratory glassware Burettes 2 ISO 1042, Laboratory glassware One-mark volumetric flasks 3 ISO 3681, Binders for paints and varnishes Determination of saponification value Titrimetric method ISO 2014 All rights reserved 5 ISO 16365-3:2014(E) ISO 2014 All rights reserved IC S 83.080.20 Price based on 5 pages
