CRYSTAF, DSC and SAXS Study of the Co-Crystallization, Phase Separation and Lamellar Packing of the Blends with Different Polyethylenes
The crystallization of polyethylene (PE) blends is a highly complex process, owing to the significant differences in crystallizability of the various PE components and the varying PE sequence distributions resulting from short- or long-chain branching. In this study, we examined both the resins and...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-04-01
|
| Series: | Polymers |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4360/15/8/1940 |
| _version_ | 1797603765671428096 |
|---|---|
| author | Xuerong Yao Ying Shi Yujing Tang Chunxia Luo Liping Hou Minqiao Ren Cui Zheng Li-Zhi Liu |
| author_facet | Xuerong Yao Ying Shi Yujing Tang Chunxia Luo Liping Hou Minqiao Ren Cui Zheng Li-Zhi Liu |
| author_sort | Xuerong Yao |
| collection | DOAJ |
| description | The crystallization of polyethylene (PE) blends is a highly complex process, owing to the significant differences in crystallizability of the various PE components and the varying PE sequence distributions resulting from short- or long-chain branching. In this study, we examined both the resins and their blends through crystallization analysis fractionation (CRYSTAF) to understand the PE sequence distribution and differential scanning calorimetry (DSC) to investigate the non-isothermal crystallization behavior of the bulk materials. Small-angle X-ray scattering (SAXS) was utilized to study the crystal packing structure. The results showed that the PE molecules in the blends crystallize at different rates during cooling, resulting in a complicated crystallization behavior characterized by nucleation, co-crystallization, and fractionation. We compared these behaviors to those of reference immiscible blends and found that the extent of the differences is related to the disparity in crystallizability between components. Furthermore, the lamellar packing of the blends is closely associated with their crystallization behaviors, and the crystalline structure varies significantly depending on the components’ compositions. Specifically, the lamellar packing of the HDPE/LLDPE and HDPE/LDPE blends is similar to that of the HDPE component owing to its strong crystallizability, while the lamellar packing of the LLDPE/LDPE blend is approximately an average of the two neat components. |
| first_indexed | 2024-03-11T04:36:39Z |
| format | Article |
| id | doaj.art-d11400ef57214ffb8c52323e5bd2be79 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-11T04:36:39Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-d11400ef57214ffb8c52323e5bd2be792023-11-17T21:02:44ZengMDPI AGPolymers2073-43602023-04-01158194010.3390/polym15081940CRYSTAF, DSC and SAXS Study of the Co-Crystallization, Phase Separation and Lamellar Packing of the Blends with Different PolyethylenesXuerong Yao0Ying Shi1Yujing Tang2Chunxia Luo3Liping Hou4Minqiao Ren5Cui Zheng6Li-Zhi Liu7SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., Beijing 100013, ChinaAdvanced Manufacturing Institute of Polymer Industry, Shenyang University of Chemical Technology, Shenyang 110142, ChinaSINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., Beijing 100013, ChinaSINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., Beijing 100013, ChinaSINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., Beijing 100013, ChinaSINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., Beijing 100013, ChinaSINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., Beijing 100013, ChinaAdvanced Manufacturing Institute of Polymer Industry, Shenyang University of Chemical Technology, Shenyang 110142, ChinaThe crystallization of polyethylene (PE) blends is a highly complex process, owing to the significant differences in crystallizability of the various PE components and the varying PE sequence distributions resulting from short- or long-chain branching. In this study, we examined both the resins and their blends through crystallization analysis fractionation (CRYSTAF) to understand the PE sequence distribution and differential scanning calorimetry (DSC) to investigate the non-isothermal crystallization behavior of the bulk materials. Small-angle X-ray scattering (SAXS) was utilized to study the crystal packing structure. The results showed that the PE molecules in the blends crystallize at different rates during cooling, resulting in a complicated crystallization behavior characterized by nucleation, co-crystallization, and fractionation. We compared these behaviors to those of reference immiscible blends and found that the extent of the differences is related to the disparity in crystallizability between components. Furthermore, the lamellar packing of the blends is closely associated with their crystallization behaviors, and the crystalline structure varies significantly depending on the components’ compositions. Specifically, the lamellar packing of the HDPE/LLDPE and HDPE/LDPE blends is similar to that of the HDPE component owing to its strong crystallizability, while the lamellar packing of the LLDPE/LDPE blend is approximately an average of the two neat components.https://www.mdpi.com/2073-4360/15/8/1940PE blendsco-crystallizationfractionationstructureCRYSTAFSAXS |
| spellingShingle | Xuerong Yao Ying Shi Yujing Tang Chunxia Luo Liping Hou Minqiao Ren Cui Zheng Li-Zhi Liu CRYSTAF, DSC and SAXS Study of the Co-Crystallization, Phase Separation and Lamellar Packing of the Blends with Different Polyethylenes Polymers PE blends co-crystallization fractionation structure CRYSTAF SAXS |
| title | CRYSTAF, DSC and SAXS Study of the Co-Crystallization, Phase Separation and Lamellar Packing of the Blends with Different Polyethylenes |
| title_full | CRYSTAF, DSC and SAXS Study of the Co-Crystallization, Phase Separation and Lamellar Packing of the Blends with Different Polyethylenes |
| title_fullStr | CRYSTAF, DSC and SAXS Study of the Co-Crystallization, Phase Separation and Lamellar Packing of the Blends with Different Polyethylenes |
| title_full_unstemmed | CRYSTAF, DSC and SAXS Study of the Co-Crystallization, Phase Separation and Lamellar Packing of the Blends with Different Polyethylenes |
| title_short | CRYSTAF, DSC and SAXS Study of the Co-Crystallization, Phase Separation and Lamellar Packing of the Blends with Different Polyethylenes |
| title_sort | crystaf dsc and saxs study of the co crystallization phase separation and lamellar packing of the blends with different polyethylenes |
| topic | PE blends co-crystallization fractionation structure CRYSTAF SAXS |
| url | https://www.mdpi.com/2073-4360/15/8/1940 |
| work_keys_str_mv | AT xuerongyao crystafdscandsaxsstudyofthecocrystallizationphaseseparationandlamellarpackingoftheblendswithdifferentpolyethylenes AT yingshi crystafdscandsaxsstudyofthecocrystallizationphaseseparationandlamellarpackingoftheblendswithdifferentpolyethylenes AT yujingtang crystafdscandsaxsstudyofthecocrystallizationphaseseparationandlamellarpackingoftheblendswithdifferentpolyethylenes AT chunxialuo crystafdscandsaxsstudyofthecocrystallizationphaseseparationandlamellarpackingoftheblendswithdifferentpolyethylenes AT lipinghou crystafdscandsaxsstudyofthecocrystallizationphaseseparationandlamellarpackingoftheblendswithdifferentpolyethylenes AT minqiaoren crystafdscandsaxsstudyofthecocrystallizationphaseseparationandlamellarpackingoftheblendswithdifferentpolyethylenes AT cuizheng crystafdscandsaxsstudyofthecocrystallizationphaseseparationandlamellarpackingoftheblendswithdifferentpolyethylenes AT lizhiliu crystafdscandsaxsstudyofthecocrystallizationphaseseparationandlamellarpackingoftheblendswithdifferentpolyethylenes |