{"id":24156,"date":"2024-07-22T09:33:37","date_gmt":"2024-07-22T07:33:37","guid":{"rendered":"https:\/\/www.linseis.com\/melting-point-crystallization-and-glass-transition-in-polymers\/"},"modified":"2024-08-27T10:26:24","modified_gmt":"2024-08-27T08:26:24","slug":"melting-point-crystallization-and-glass-transition-in-polymers","status":"publish","type":"post","link":"https:\/\/www.linseis.com\/en\/wiki\/melting-point-crystallization-and-glass-transition-in-polymers\/","title":{"rendered":"Melting point, crystallization, and glass transition in polymers"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"24156\" class=\"elementor elementor-24156 elementor-14796\" 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-4862a37 elementor-toc--minimized-on-tablet elementor-widget elementor-widget-table-of-contents\" data-id=\"4862a37\" 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__4862a37\" 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__4862a37\" 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__4862a37\" 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-8a9139e elementor-widget elementor-widget-heading\" data-id=\"8a9139e\" 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\">Melting and crystallization<\/h2>\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>The change in the physical state of a<strong> solid from solid to liquid is known as melting<\/strong>. The heat supplied dissolves the crystal lattice with the temperature of the material remaining constant during the entire melting process. So, there is a defined melting temperature.<\/p>\n<p>The reversal of this first order phase, the <strong>transition from the amorphous-liquid state of the melt to the crystalline state, is called crystallization<\/strong>. It is a kinetically controlled process and depends primarily on nucleation. Therefore, the crystallization temperature is always below the thermodynamically controlled melting temperature.<\/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-a96105b elementor-widget elementor-widget-heading\" data-id=\"a96105b\" 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\">Glass transition<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e538af1 elementor-widget elementor-widget-text-editor\" data-id=\"e538af1\" 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>Non-crystalline materials such as polymers, on the other hand, have a glass transition. This is where completely or partially<strong> amorphous polymers change from a highly viscous or rubber-elastic, flexible state to a glass-like or hard-elastic, brittle state<\/strong>. To characterize the glass transition, the glass transition temperature Tg expresses the point at which half of the change in the <a href=\"https:\/\/www.linseis.com\/en\/properties\/specific-heat-capacity\/\"><strong>specific heat capacity<\/strong><\/a> is reached. It is also called the glass transition temperature or softening temperature.<\/p><p>The thermal glass transition is observed when a melt which cannot crystallize is supercooled. The so-called cooperative molecular movements, such as rearrangements of main chain segments, side chain rotations, and end group rotations, then \u201cfreeze.\u201d This results in sudden changes in mechanical and thermodynamic properties such as <a href=\"https:\/\/www.linseis.com\/en\/properties\/youngs-modulus\/\"><strong>modulus of elasticity<\/strong><\/a>, specific heat capacity, and <a href=\"https:\/\/www.linseis.com\/en\/properties\/linear-expansion-coefficient\/\"><strong>the coefficient of thermal expansion<\/strong><\/a>.<\/p><p><strong>The cooling rate has a decisive influence on the glass transition temperature.<\/strong> If the melt is cooled down quickly, the glass transition temperature is higher. With an infinitely slow cooling, there is no glass transition, since no amorphous partial areas result.<\/p><p>Many common plastics are partially crystalline: they therefore have a glass transition temperature below which the amorphous phase freezes. At the same time, they also have a melting temperature at which the crystalline area dissolves.<\/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-48f57e6 elementor-widget elementor-widget-heading\" data-id=\"48f57e6\" 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\"> Polymers can be classified based on their glass transition<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0c9d099 elementor-widget elementor-widget-text-editor\" data-id=\"0c9d099\" 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<section class=\"container\">\n<div class=\"row\">\n<div class=\"spb_content_element col-sm-12 spb_text_column\">\n<div class=\"spb_wrapper clearfix\">\n<p>Since <strong>every plastic has a specific glass transition<\/strong>, this is an important parameter for characterizing the material. Therefore, the determination of the glass transition temperature is often used in thermal analysis, in order to make such statements as the dimensional stability of a polymer under the action of heat.<\/p>\n<p>For example, elastomers are only used in the rubber-elastic range, i.e. above the glass transition temperature. In contrast, amorphous thermoplastics are only used below T<sub>g<\/sub>.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n<section class=\"container\">\n<div class=\"row\">\n<div class=\"spb_content_element col-sm-12 spb_text_column\">\n<div class=\"spb_wrapper clearfix\">\n<p>Since the glass transition depends on the type of plastic and its manufacture, information on changes in the material can be obtained by determining the T<sub>g<\/sub>.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\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-47f98c6 elementor-widget elementor-widget-spacer\" data-id=\"47f98c6\" 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-96bbf54 elementor-widget elementor-widget-spacer\" data-id=\"96bbf54\" 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-ec070c6 elementor-widget elementor-widget-text-editor\" data-id=\"ec070c6\" 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>Among other things, the following relationships exist:<\/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-9b6de7f elementor-widget elementor-widget-text-editor\" data-id=\"9b6de7f\" 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<ul>\n<li>Chemical structure: the more flexible the main chain, the lower the T<sub>g<\/sub><\/li>\n<li>Molar mass: the T<sub>g<\/sub>\u00a0increases as molar mass increases<\/li>\n<li>Molecular orientation, e.g. T<sub>g<\/sub>\u00a0increases in foils<\/li>\n<li>Crosslinking, the T<sub>g<\/sub>\u00a0increases as the degree of crosslinking increases<\/li>\n<li>Plasticizers: the T<sub>g<\/sub>\u00a0decreases as the plasticizer content increases.<\/li>\n<\/ul>\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-ad2f93d elementor-widget elementor-widget-spacer\" data-id=\"ad2f93d\" 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-0b5a111 elementor-widget elementor-widget-spacer\" data-id=\"0b5a111\" 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-aecb021 elementor-widget elementor-widget-text-editor\" data-id=\"aecb021\" 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 glass transition temperature also provides information on the physical aging of plastics, which occurs as an enthalpy relaxation peak in DSC measurements. Polymer mixtures can also be characterized using Tg. If the polymers are immiscible, the individual components appear phase-separated so that they exist side-by-side and several glass transitions can be measured. A comparison with the pure components can provide information about the proportions and quality of the mixing process.<\/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-ed917bc elementor-widget elementor-widget-spacer\" data-id=\"ed917bc\" 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-92336ab elementor-widget elementor-widget-spacer\" data-id=\"92336ab\" 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-c223453 elementor-widget elementor-widget-text-editor\" data-id=\"c223453\" 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>Further information on determining the <a href=\"https:\/\/www.linseis.com\/en\/wiki\/glass-transition-temperature\/\"><strong>glass transition temperature<\/strong><\/a>.<\/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-8db1afe elementor-widget elementor-widget-spacer\" data-id=\"8db1afe\" 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>Melting point, crystallization and glass transition in polymers &#8211; The change in the aggregate state of a solid from solid to liquid is called melting.<\/p>\n","protected":false},"author":3,"featured_media":14806,"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-24156","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\/24156","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=24156"}],"version-history":[{"count":0,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts\/24156\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/media\/14806"}],"wp:attachment":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/media?parent=24156"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/categories?post=24156"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/tags?post=24156"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}