ISO 1628-2:1998 使用毛细管粘度计测定稀释溶液中聚合物的粘度.第2部分：聚（氯乙烯）树脂

标准编号：ISO 1628-2:1998

中文名称：使用毛细管粘度计测定稀释溶液中聚合物的粘度.第2部分：聚（氯乙烯）树脂

英文名称：Plastics — Determination of the viscosity of polymers in dilute solution using capillary viscometers — Part 2: Poly(vinyl chloride) resins

发布日期：1998-12

标准范围

ISO 1628的这一部分规定了测定还原粘度（也称为粘度数）和PVC树脂的K值。它适用于由以下均聚物组成的粉末形式的树脂单体氯乙烯和氯乙烯与一种或多种其它单体的共聚物、三元共聚物等，但是其中氯乙烯是主要成分。树脂可以含有少量的未聚合物质(例如。乳化剂或悬浮剂、催化剂残留物等）以及在聚合。然而，ISO 1628的这一部分不适用于挥发物含量超过0.5%±0.1%，根据ISO 1269测定。除此之外，它不适用于以下树脂:不完全溶于环己酮。特定树脂的还原粘度和K值与其分子量有关，但这种关系各不相同取决于存在的其它单体的浓度和类型。因此均聚物和共聚物具有相同的还原粘度或K值可能不具有相同的分子量。对于PVC树脂的特定样品，测定的降低粘度和K值的值受到影响根据选择用于测定的溶液的浓度而不同。因此使用所描述的程序在ISO 1628的这一部分中，仅给出当所用溶液的浓度相同。PVC树脂不使用极限粘度值。ISO 1628这一部分中描述的实验程序也可用于表征聚合物级分在PVC组合物的化学分析过程中获得。然而，对于降低的粘度计算的值这些情况下的K值可能不表示用于生产组合物的树脂的实际值因为回收的聚合物级分的不纯性质。

This part of ISO 1628 specifies conditions for the determination of the reduced viscosity (also known as viscositynumber) and K-value of PVC resins. It is applicable to resins in powder form which consist of homopolymers of themonomer vinyl chloride and copolymers, terpolymers, etc., of vinyl chloride with one or more other monomers, butwhere vinyl chloride is the main constituent. The resins may contain small amounts of unpolymerized substances (e.g.emulsifying or suspending agents, catalyst residues, etc.) and other substances added during the course of thepolymerization. This part of ISO 1628 is not applicable, however, to resins having a volatile-matter content in excess of0,5 % ± 0,1 %, when determined in accordance with ISO 1269. In addition to this, it is not applicable to resins which arenot entirely soluble in cyclohexanone.The reduced viscosity and K-value of a particular resin are related to its molecular mass, but the relationship variesdepending on the concentration and type(s) of other monomer(s) present. Hence homopolymers and copolymershaving the same reduced viscosity or K-value may not have the same molecular mass.The values determined for reduced viscosity and K-value, for a particular sample of PVC resin, are influenceddifferently by the concentration of the solution chosen for the determination. Hence the use of the procedures describedin this part of ISO 1628 will only give values for reduced viscosity and K-value that are comparable when theconcentrations of the solutions used are identical.Limiting viscosity number is not used for PVC resins.The experimental procedures described in this part of ISO 1628 can also be used to characterize the polymeric fractionobtained during the chemical analysis of a PVC composition. However, the values calculated for the reduced viscosityand K-value in these circumstances may not indicate the actual values for the resin used to produce the compositionbecause of the impure nature of the recovered polymer fraction.

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