Abstract

Mixtures of low-density polyethylene (T_m = 108°C, enthalpy of melting 80 J g^–1) with 90 wt % indigo, lophine, bromcresol purple, spiropyran, phenol red, rhodamine, phenolphthalein, and fluorescein were subjected to plastic deformation under a pressure of 1 GPa on an anvils-type high-pressure apparatus. The study of deformed mixtures was carried out by the DSC method. The thermograms of heating the mixtures showed peaks of polymer melting with enthalpies, which varied from 25 to 170 J g^–1. The thermograms below the polymer temperature showed either endotherm peaks of melting of fine crystallites with maxima at 44–57°С, the enthalpies of which varied within 20–120 J g^–1, or exotherm peaks of crystallization of fine crystallites with maxima at 58–67°С and enthalpies from 20 up to 45 J g^–1. In the range of 81–86°С, in some mixtures, the exotherm process of cold polymer crystallization took place, the enthalpy of which varied from 75 to 290 J g^–1. At temperatures above the polymer T_m in the range 115–132°С, the heating thermograms showed exotherm peaks with enthalpies from 115 to 420 J g^–1, while, in the range 137–164°С, they showed endotherm peaks with enthalpies of 520–540 J g^–1. Crystallization of most mixtures from the melt was described by two peaks, one of which was always at 87°С, while the other could be at 48 or 112°С. The total enthalpies of crystallization varied from 40 to 82 J g^–1.

中文翻译：

---

低密度聚乙烯与 90 wt% 低分子量有机化合物的混合物在高压下塑性变形后的放热效应

摘要

低密度聚乙烯（T _m = 108°C，熔化焓 80 J g ^–1）与 90 wt% 靛蓝、洛芬、溴甲酚紫、螺吡喃、酚红、罗丹明、酚酞和荧光素的混合物进行塑性变形在 1 GPa 的压力下，在砧式高压装置上进行。变形混合物的研究是通过 DSC 方法进行的。加热混合物的热谱图显示了聚合物熔化焓的峰值，从 25 到 170 J g ^{–1 不等}。低于聚合物温度的热谱图显示了细晶粒熔化的吸热峰，最大值在 44–57°С，其焓在 20–120 J g ^–1范围内变化，或细晶粒结晶放热峰，最大值为 58–67°С，焓为 20 至 45 J g ^–1。在81-86°С范围内，一些混合物发生冷聚合物结晶的放热过程，其焓在75至290 J g ^{–1 之间变化}。在高于聚合物T _{m 的}温度范围内，在 115–132°С 范围内，加热热谱图显示出放热峰，焓为 115 至 420 J g ^–1，而在 137–164°С 范围内，它们显示出焓的吸热峰520–540 J g ^–1. 大多数混合物从熔体中结晶出两个峰，其中一个总是在 87°С，而另一个可能在 48 或 112°С。总结晶焓从 40 到 82 J g ^{–1 不等}。