This part of ISO 1628 specifies conditions for the determination of the reduced viscosity (also known as viscosity<\/p>\n
number) and K-<\/i>value of PVC resins. It is applicable to resins in powder form which consist of homopolymers of the<\/p>\n
monomer vinyl chloride and copolymers, terpolymers, etc., of vinyl chloride with one or more other monomers, but<\/p>\n
where vinyl chloride is the main constituent. The resins may contain small amounts of unpolymerized substances (e.g.<\/p>\n
emulsifying or suspending agents, catalyst residues, etc.) and other substances added during the course of the<\/p>\n
polymerization. This part of ISO 1628 is not applicable, however, to resins having a volatile-matter content in excess of<\/p>\n
0,5 % \u00b1 0,1 %, when determined in accordance with ISO 1269. In addition to this, it is not applicable to resins which are<\/p>\n
not entirely soluble in cyclohexanone.<\/p>\n
The reduced viscosity and K-<\/i>value of a particular resin are related to its molecular mass, but the relationship varies<\/p>\n
depending on the concentration and type(s) of other monomer(s) present. Hence homopolymers and copolymers<\/p>\n
having the same reduced viscosity or K-<\/i>value may not have the same molecular mass.<\/p>\n
The values determined for reduced viscosity and K-<\/i>value, for a particular sample of PVC resin, are influenced<\/p>\n
differently by the concentration of the solution chosen for the determination. Hence the use of the procedures described<\/p>\n
in this part of ISO 1628 will only give values for reduced viscosity and K-<\/i>value that are comparable when the<\/p>\n
concentrations of the solutions used are identical.<\/p>\n
Limiting viscosity number is not used for PVC resins.<\/p>\n
The experimental procedures described in this part of ISO 1628 can also be used to characterize the polymeric fraction<\/p>\n
obtained during the chemical analysis of a PVC composition. However, the values calculated for the reduced viscosity<\/p>\n
and K-<\/i>value in these circumstances may not indicate the actual values for the resin used to produce the composition<\/p>\n
because of the impure nature of the recovered polymer fraction.<\/p>\n","protected":false},"excerpt":{"rendered":"
Plastics \u2014 Determination of the viscosity of polymers in dilute solution using capillary viscometers \u2014 Part 2: Poly(vinyl chloride) resins<\/b><\/p>\n\n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n ISO<\/b><\/a><\/td>\n 1998-12<\/td>\n 20<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":597009,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[1179,2634],"product_tag":[],"class_list":{"0":"post-596995","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-83-080-20","7":"product_cat-iso","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/596995","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/597009"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=596995"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=596995"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=596995"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}