{"id":24177,"date":"2024-07-22T11:17:04","date_gmt":"2024-07-22T09:17:04","guid":{"rendered":"https:\/\/www.linseis.com\/curing-in-thermal-analysis\/"},"modified":"2024-09-13T15:14:27","modified_gmt":"2024-09-13T13:14:27","slug":"curing-in-thermal-analysis","status":"publish","type":"post","link":"https:\/\/www.linseis.com\/en\/wiki\/curing-in-thermal-analysis\/","title":{"rendered":"Curing in thermal analysis"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"24177\" class=\"elementor elementor-24177 elementor-15335\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-9eb8745 e-flex e-con-boxed e-con e-parent\" data-id=\"9eb8745\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-d0d9157 elementor-toc--minimized-on-tablet elementor-widget elementor-widget-table-of-contents\" data-id=\"d0d9157\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;headings_by_tags&quot;:[&quot;h2&quot;],&quot;exclude_headings_by_selector&quot;:[],&quot;marker_view&quot;:&quot;numbers&quot;,&quot;no_headings_message&quot;:&quot;No headings were found on this page.&quot;,&quot;minimize_box&quot;:&quot;yes&quot;,&quot;minimized_on&quot;:&quot;tablet&quot;,&quot;hierarchical_view&quot;:&quot;yes&quot;,&quot;min_height&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]},&quot;min_height_tablet&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]},&quot;min_height_mobile&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]}}\" data-widget_type=\"table-of-contents.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-toc__header\">\n\t\t\t\t\t\t<h4 class=\"elementor-toc__header-title\">\n\t\t\t\tTable of Contents\t\t\t<\/h4>\n\t\t\t\t\t\t\t\t\t\t<div class=\"elementor-toc__toggle-button elementor-toc__toggle-button--expand\" role=\"button\" tabindex=\"0\" aria-controls=\"elementor-toc__d0d9157\" aria-expanded=\"true\" aria-label=\"Open table of contents\"><svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-down\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M207.029 381.476L12.686 187.132c-9.373-9.373-9.373-24.569 0-33.941l22.667-22.667c9.357-9.357 24.522-9.375 33.901-.04L224 284.505l154.745-154.021c9.379-9.335 24.544-9.317 33.901.04l22.667 22.667c9.373 9.373 9.373 24.569 0 33.941L240.971 381.476c-9.373 9.372-24.569 9.372-33.942 0z\"><\/path><\/svg><\/div>\n\t\t\t\t<div class=\"elementor-toc__toggle-button elementor-toc__toggle-button--collapse\" role=\"button\" tabindex=\"0\" aria-controls=\"elementor-toc__d0d9157\" aria-expanded=\"true\" aria-label=\"Close table of contents\"><svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-up\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M240.971 130.524l194.343 194.343c9.373 9.373 9.373 24.569 0 33.941l-22.667 22.667c-9.357 9.357-24.522 9.375-33.901.04L224 227.495 69.255 381.516c-9.379 9.335-24.544 9.317-33.901-.04l-22.667-22.667c-9.373-9.373-9.373-24.569 0-33.941L207.03 130.525c9.372-9.373 24.568-9.373 33.941-.001z\"><\/path><\/svg><\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<div id=\"elementor-toc__d0d9157\" class=\"elementor-toc__body\">\n\t\t\t<div class=\"elementor-toc__spinner-container\">\n\t\t\t\t<svg class=\"elementor-toc__spinner eicon-animation-spin e-font-icon-svg e-eicon-loading\" aria-hidden=\"true\" viewBox=\"0 0 1000 1000\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M500 975V858C696 858 858 696 858 500S696 142 500 142 142 304 142 500H25C25 237 238 25 500 25S975 237 975 500 763 975 500 975Z\"><\/path><\/svg>\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ffaef65 elementor-widget elementor-widget-text-editor\" data-id=\"ffaef65\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Materials that are processed in a liquid state of aggregation generally require a certain amount of time to cure. During this time, chemical and physical processes take place, leading to the hardening of the material. These processes are associated with the release or absorption of heat.<\/p><p>By recording the corresponding quantities of heat using <a href=\"https:\/\/www.linseis.com\/en\/products\/dsc-differential-scanning-calorimetry\/\"><strong>differential scanning calorimetry (DSC)<\/strong><\/a>, the course of the processes can be observed as a function of defined environmental conditions. <strong>The results provide information about optimum conditions for curing and allow conclusions to be drawn about the quality parameters of the material under investigation.<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-dcb32f8 elementor-widget elementor-widget-heading\" data-id=\"dcb32f8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Curing of duroplasts and elastomers<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0de80db elementor-widget elementor-widget-text-editor\" data-id=\"0de80db\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Duromers or also duroplastics and elastomers are plastics that obtain their final strength by cross-linking macromolecules. Chemical bonds are formed at reactive groups.<\/p>\n<p><strong>The reactions start by raising the temperature and adding substances (hardeners) which form a bridge between the reactive groups.<\/strong><\/p>\n<p>Duromers form a close-meshed spatial network. They thus achieve a high degree of strength. The network of elastomers is wide-meshed. Its ball-shaped macromolecules can be pulled apart and return to their original state when the tensile force is removed. <strong>After complete cross-linking, the plastics are dimensionally stable. The process is called curing.<\/strong><\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-eac9a92 elementor-widget__width-initial elementor-widget elementor-widget-image\" data-id=\"eac9a92\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"800\" height=\"450\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Overview-of-plastic-molecules-2-1024x576-1.png\" class=\"attachment-large size-large wp-image-37534\" alt=\"\" srcset=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Overview-of-plastic-molecules-2-1024x576-1.png 1024w, https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Overview-of-plastic-molecules-2-1024x576-1-300x169.png 300w, https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Overview-of-plastic-molecules-2-1024x576-1-768x432.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Overview of the molecular structure of thermoplastics, elastomers and thermosets<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-580265d elementor-widget elementor-widget-heading\" data-id=\"580265d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Examples of amorphous thermoplastics:<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d7a825d elementor-widget elementor-widget-text-editor\" data-id=\"d7a825d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>PS in toys, bobbins and films, PVC in containers, pipes, films, sound and heat insulation, tablecloths<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7d5b5be elementor-widget elementor-widget-heading\" data-id=\"7d5b5be\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Examples of semi-crystalline thermoplastics:<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ae2cce9 elementor-widget elementor-widget-text-editor\" data-id=\"ae2cce9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>PE in containers, bottles, pipes, corrosion protection layers, PP in insulating films, pipes or adhesive tape<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-712d2d1 elementor-widget elementor-widget-heading\" data-id=\"712d2d1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Examples of thermosets:<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8b0ad1e elementor-widget elementor-widget-text-editor\" data-id=\"8b0ad1e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>PF (phenolic resin) and UP (polyester resin) in heat-resistant and electrically insulated handles<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8acdc97 elementor-widget elementor-widget-heading\" data-id=\"8acdc97\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Examples of elastomers:<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8eaf021 elementor-widget elementor-widget-text-editor\" data-id=\"8eaf021\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>polyurethane in resilient machine parts, sports fields, ski boots<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-993d023 elementor-widget elementor-widget-spacer\" data-id=\"993d023\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-eef0db3 elementor-widget elementor-widget-spacer\" data-id=\"eef0db3\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f9e01b4 elementor-widget elementor-widget-text-editor\" data-id=\"f9e01b4\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>During curing, a plastic passes through different phases. The starting material is usually in the form of a liquid solution. This means that the macromolecules are finely distributed in a solvent. At a minimum temperature that depends on the polymer system, cross-linking reactions begin in the solution, which results in a gel. The gel consists of the now insoluble, cross-linked components, the spaces between which enclose solvents. The mixture of sol and gel is initially rubber-elastic.<\/p><p>In thermoset systems, it reaches a glassy state with increasing cross-linking. Curing continues until the maximum degree of cure, at which point the sol is completely converted into a gel.<\/p><p>In elastomer systems, the gel retains its rubber-elastic state after complete cross-linking. The respective behavior is ultimately decisively determined by the <a href=\"https:\/\/www.linseis.com\/en\/wiki\/glass-transition-temperature\/\"><strong>glass transition temperature<\/strong><\/a> of the polymer system. In duromers it is above the curing temperature, in elastomers below. Above the glass transition temperature, the polymer is soft and the molecules are mobile, below it the material is rather solid and brittle.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c0d73d8 elementor-widget__width-initial elementor-widget elementor-widget-image\" data-id=\"c0d73d8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"560\" height=\"315\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Mechanismus-der-entropieelastischen-Formaenderung.png\" class=\"attachment-large size-large wp-image-15468\" alt=\"\" srcset=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Mechanismus-der-entropieelastischen-Formaenderung.png 560w, https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Mechanismus-der-entropieelastischen-Formaenderung-300x169.png 300w\" sizes=\"(max-width: 560px) 100vw, 560px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Mechanism of the cross-linking reaction (entropieelastic deformation)<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-def93a8 elementor-widget elementor-widget-heading\" data-id=\"def93a8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">The curing level<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-577bcd6 elementor-widget elementor-widget-text-editor\" data-id=\"577bcd6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>The period of time during which curing takes place depends on the material properties of the polymer system and the temperature.<\/p>\n<p>Below a system-dependent temperature limit, no significant cross-linking takes place. Although the sol becomes solid over a longer period of time, it can be liquefied again by heating.<\/p>\n<p>Above this temperature limit, the crosslinking reactions start after a certain \u201crest period\u201d. The \u201cresting time\u201d is shortened and the reaction rate increases as the temperature rises.<\/p>\n<p>The cross-linking reaction is irreversible. How long the initial mixture can be processed depends on the resting time. <strong>This period is called pot life. It can be extended by adding inhibitors and shortened by adding catalysts.<\/strong><\/p>\n<p>The reaction rate determines how much time the polymer system needs until complete curing. The addition of inhibitors or catalysts can also be controlled by this time period. However, the temperature at which the crosslinking takes place has a significant influence. How far this has progressed is described by the degree of curing. It is the percentage of the mixture that has already cross-linked. The maximum degree of curing is reached when the entire sol has been converted into a gel.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-59ede73 elementor-widget elementor-widget-heading\" data-id=\"59ede73\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">The enthalpy of reaction<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4188278 elementor-widget elementor-widget-text-editor\" data-id=\"4188278\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>The cross-linking reaction is exothermic, i.e. it takes place under release of heat. Since the processes take place at constant pressure, only the heat amount that is not consumed by heat-related volume changes can be determined. This portion is the reaction enthalpy. It can be determined by thermal analysis for the reaction that has been completed.<\/p>\n<p>By <strong>differential scanning calorimetry (DSC) can be determined, what heat quantity per time unit becomes free<\/strong>. This value corresponds to the reaction speed. The amount of heat released up to a certain point in time can be put into relation to the enthalpy of the reaction. <strong>This ratio is equal to the degree of curing.<\/strong><\/p>\n<p>The values obtained make it possible to determine the optimum curing temperature and degree of curing of samples, to determine the appropriate mixing ratio of sol and hardener and to assess the effectiveness of inhibitors and catalysts.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f96c1c0 elementor-widget elementor-widget-spacer\" data-id=\"f96c1c0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Materials that are processed in a liquid aggregate state generally require a certain amount of time to harden.<\/p>\n","protected":false},"author":3,"featured_media":15338,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[106],"tags":[],"class_list":["post-24177","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-wiki"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts\/24177","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/comments?post=24177"}],"version-history":[{"count":0,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts\/24177\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/media\/15338"}],"wp:attachment":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/media?parent=24177"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/categories?post=24177"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/tags?post=24177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}