Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete Melting
While existing foam studies have identified processing parameters, such as high-pressure drop rate, and engineering measures, such as high melt strength, as key factors for improving foamability, there is a conspicuous absence of studies that directly relate foamability to material properties obtain...
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| Format: | Article |
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MDPI AG
2021-12-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/14/1/44 |
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| author | Mu Sung Kweon Mahmoud Embabi Maksim E. Shivokhin Anvit Gupta Xuejia Yan George Pehlert Patrick C. Lee |
| author_facet | Mu Sung Kweon Mahmoud Embabi Maksim E. Shivokhin Anvit Gupta Xuejia Yan George Pehlert Patrick C. Lee |
| author_sort | Mu Sung Kweon |
| collection | DOAJ |
| description | While existing foam studies have identified processing parameters, such as high-pressure drop rate, and engineering measures, such as high melt strength, as key factors for improving foamability, there is a conspicuous absence of studies that directly relate foamability to material properties obtained from fundamental characterization. To bridge this gap, this work presents batch foaming studies on one linear and two long-chain branched polypropylene (PP) resins to investigate how foamability is affected by partial melting (Method 1) and complete melting followed by undercooling (Method 2). At temperatures above the melting point, similar expansion was obtained using both foaming procedures within each resin, while the PP with the highest strain hardening ratio (13) exhibited the highest expansion ratio (45 ± 3). At low temperatures, the foamability of all resins was dramatically improved using Method 2 compared to Method 1, due to access to lower foaming temperatures (<150 °C) near the crystallization onset. Furthermore, Method 2 resulted in a more uniform cellular structure over a wider temperature range (120–170 °C compared to 155–175 °C). Overall, strong extensional hardening and low onset of crystallization were shown to give rise to foamability at high and low temperatures, respectively, suggesting that both characteristics can be appropriately used to tune the foamability of PP in industrial foaming applications. |
| first_indexed | 2024-03-10T03:26:24Z |
| format | Article |
| id | doaj.art-c83eeb70e05a417196c02a162e39f0f4 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T03:26:24Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-c83eeb70e05a417196c02a162e39f0f42023-11-23T12:09:02ZengMDPI AGPolymers2073-43602021-12-011414410.3390/polym14010044Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete MeltingMu Sung Kweon0Mahmoud Embabi1Maksim E. Shivokhin2Anvit Gupta3Xuejia Yan4George Pehlert5Patrick C. Lee6Multifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, CanadaMultifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, CanadaExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, TX 77520, USAExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, TX 77520, USAExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, TX 77520, USAExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, TX 77520, USAMultifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, CanadaWhile existing foam studies have identified processing parameters, such as high-pressure drop rate, and engineering measures, such as high melt strength, as key factors for improving foamability, there is a conspicuous absence of studies that directly relate foamability to material properties obtained from fundamental characterization. To bridge this gap, this work presents batch foaming studies on one linear and two long-chain branched polypropylene (PP) resins to investigate how foamability is affected by partial melting (Method 1) and complete melting followed by undercooling (Method 2). At temperatures above the melting point, similar expansion was obtained using both foaming procedures within each resin, while the PP with the highest strain hardening ratio (13) exhibited the highest expansion ratio (45 ± 3). At low temperatures, the foamability of all resins was dramatically improved using Method 2 compared to Method 1, due to access to lower foaming temperatures (<150 °C) near the crystallization onset. Furthermore, Method 2 resulted in a more uniform cellular structure over a wider temperature range (120–170 °C compared to 155–175 °C). Overall, strong extensional hardening and low onset of crystallization were shown to give rise to foamability at high and low temperatures, respectively, suggesting that both characteristics can be appropriately used to tune the foamability of PP in industrial foaming applications.https://www.mdpi.com/2073-4360/14/1/44linear and long-chain branched polypropylenebatch foaminghigh-pressure differential scanning calorimetrycrystallization onset temperatureextensional hardeningstrain hardening ratio |
| spellingShingle | Mu Sung Kweon Mahmoud Embabi Maksim E. Shivokhin Anvit Gupta Xuejia Yan George Pehlert Patrick C. Lee Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete Melting Polymers linear and long-chain branched polypropylene batch foaming high-pressure differential scanning calorimetry crystallization onset temperature extensional hardening strain hardening ratio |
| title | Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete Melting |
| title_full | Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete Melting |
| title_fullStr | Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete Melting |
| title_full_unstemmed | Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete Melting |
| title_short | Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete Melting |
| title_sort | tuning high and low temperature foaming behavior of linear and long chain branched polypropylene via partial and complete melting |
| topic | linear and long-chain branched polypropylene batch foaming high-pressure differential scanning calorimetry crystallization onset temperature extensional hardening strain hardening ratio |
| url | https://www.mdpi.com/2073-4360/14/1/44 |
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