标准编号:	GB/T 32681-2016
中文名称:	塑料 酚醛树脂 用差示扫描量热计法 测定反应热和反应温度
英文名称:	Plastics. Phenolic resins. Determination of heats and temperatures of reaction by differential scanning calorimetry
中标分类:	G31    合成树脂、塑料基础标准与通用方法
行业分类:	GB    国家标准
ICS分类:	83.080.10 83.080.10    热固性塑料 83.080.10
发布机构:	中华人民共和国国家质量监督检验检疫总局、中国国家标准化管理委员会
发布日期:	2016-06-14
实施日期:	2017-1-1
标准状态:	valid
翻译语言:	英文
文件格式:	PDF
翻译字数:	11000 字
交付时间:	1 个工作日

Plastics - Phenolic resins - Determination of heats and temperatures of reaction by differential scanning calorimetry 1 Scope 1.1 This standard specifies a method for the determination of heats and temperatures of reaction of phenolic resins by differential scanning calorimetry. 1.2 The method is applicable to phenolic resins with exothermic behaviour, such as resols or mixtures of novolaks with hexamethylenetetramine or other curing agents. 1.3 The method is useful for the characterization of products and for research. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 2035-2008 Terms and definitions for plastics (ISO 472: 1999, IDT) ISO 5725: 1986 Precision of test methods - Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 differential scanning calorimetry; DSC technique whereby the difference in energy absorbed or released by a polymer and by a reference material is measured as a function of temperature and/or time while the polymer and the reference are subjected to the same temperature schedule 3.2 phenolic resin a class of resins made by polycondensation of phenol, its homologues and/or derivatives, with aldehydes or ketones   3.3 novolac non-self-curing, soluble, fusible phenolic resins that remain stable when stored, the phenol nuclei of which are linked primarily by methylene bridges. Novolaks can be made to react further and crosslink by the addition of hardeners; heating is also usually necessary. See the content about novolac in GB/T 2035-2008. 3.4 resole soluble, fusible phenolic resins which, in contrast to novolaks, contain methylol groups and methylene-ether and sometimes also methyleneamine bridges, which are self-curing, crosslink into insoluble products when heated and/or mixed with catalysts, without addition of further reaction components, and are perishable and can be stored for a limited time only Note: For the purpose of this standard, the term “heat” and “heat of reaction” used throughout the text are equivalent to the terms “enthalpy” and “enthalpy of reaction”.

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Test method

1 范围 本标准规定了包装用氨基树脂、酚醛树脂中甲醛含量及其成型品中甲醛迁移量的高效液相色谱测定方法。 本标准适用于包装用氨基树脂、酚醛树脂中甲醛含量及其成型品中甲醛迁移量的测定。涂膜中甲醛迁移量的测定可参照使用。 2 规范性引用文件 下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。 GB/T 601 化学试剂 标准滴定溶液的制备 GB/T 5009.156 食品用包装材料及其制品的浸泡试验方法通则 GB/T 6682 分析实验室用水规格和试验方法 3 原理 样品经蒸馏或浸泡后得到的甲醛提取液，与2，4-二硝基苯肼(2，4-Dinitrophenylhydrazine， DNPH)进行衍生化反应，生成2，4-二硝基苯腙，采用高效液相色谱法测定甲醛含量。甲醛与2，4-二硝基苯肼的反应式如下： 2，4-二硝基苯肼及2，4-二硝基苯腙参考谱图见附录A。 4 试剂与材料 除非另有说明，所有试剂均为分析纯，水为GB/T 6682规定的一级水。 4.1 异丙醇。 4.2 乙腈(色谱纯)。 4.3 二硝基苯肼(DNPH)。 4.4 浓磷酸(85％)。 4.5 1％二硝基苯肼(DNPH)溶液：先将DNPH用25％的乙腈水溶液重结晶纯化，再称取纯化的DNPH 1g溶于100mL浓磷酸(85％)中(现配现用)。 4.6 硫酸溶液(1＋359)。 4.7 甲醛溶液：浓度约37％(质量分数)。 4.8 硫代硫酸钠标准滴定溶液(0.1mol/L)。 4.9 1％淀粉溶液：现配现用。 4.10 碘标准滴定溶液 。 4.11 氢氧化钠溶液(40g/L)。 4.12 硫酸溶液(1＋35)。 4.13 甲醛标准储备溶液。 4.13.1 配制：吸取10.0mL甲醛溶液(见4.7)移入装有100mL水的500mL容量瓶中，加入0.5mL硫酸溶液(见4.12)，用水稀释至刻度，该溶液为甲醛标准储备液。 4.13.2 标定：吸取甲醛标准储备液(见4.13.1)5.00mL溶液到250mL碘量瓶中，加入40.0mL碘标准滴定溶液(见4.10)，15mL氢氧化钠溶液(见4.11)，混匀，在18℃～26℃的环境中避光放置(15±1)min，然后加入20mL硫酸溶液(见4.12)，振荡。再放置10min，加入100mL水，摇匀，随后加入2mL淀粉溶液(见4.9)，过量的碘用硫代硫酸钠标准滴定溶液(见4.8)滴定到蓝色消失。平行测定3次。 按同样方式对空白溶液进行滴定。 4.13.3 浓度计算：按式(1)计算甲醛标准储备溶液浓度。