Pdla katkısı ve kesit şeklinin, PLLA filament ipliklerinin morfoloji, termal ve hidrolitik bozunmalarına olan etkilerinin araştırılması
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Tarih
2022
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info:eu-repo/semantics/openAccess
Özet
Bu tez çalışmasında Poli L Laktik Asit (PLLA) polimerine katkı malzemesi katılarak ve özel kesitli düzeler kullanılarak yapısal ve fiziksel özellikleri geliştirilmiş PLLA filament iplikleri üretilmiştir. Katkı olarak Poli D Laktik Asit (PDLA), özel kesitli düze olarak da üçgen, artı, içi boş daire ve yassı kesitli düzeler kullanılmıştır. Bu çalışmanın amaçları; PLLA polimerinin sert-kırılgan yapısını azaltarak iplik üretim performansı iyileştirmek ve PLLA filament ipliklerin sünekliğini arttırmak, ürün fiziksel özelliklerini bozmadan termal ve hidrolitik bozunmayı hızlandırarak dolaylı biçimde PLLA'nın en büyük dezavantajlarından biri olarak görülen yavaş biyobozunma özelliğini iyileştirmektir. Tezin ilk kısmında öncelikle ekstrüzyon prosesinde PDLA katkılı (%3, %6 ve %9) PLLA karışımları üretilmiştir. Daha sonra bu karışımlardan aynı iplik eğirme parametreleri kullanılarak pilot ölçekli makinada FDY (tam çekimli iplik) filament iplikler üretilmiştir. Karışımlar viskozite, karboksil, kül, DSC testleriyle karakterize edilirken, filament iplikler viskozite, karboksil, mukavemet, kopma uzama, düzgünsüzlük, kaynama çekme ve DSC testleriyle karakterize edilmiştir. Katkının hem karışımlarda hem de filament ipliklerde % kristalinite değerini oldukça düşürdüğü tespit edilmiştir. Tezin ikinci kısmında ise PLLA polimerinden özel kesitlerde filament iplik üretimleri gerçekleştirilmiştir. Özel kesit olarak üçgen, artı, içi boş daire ve yassı kesitli düzeler kullanılırken referans olaraksa dairesel kesit kullanılmıştır. Aynı eğirme parametreleriyle üretilen FDY kalitesinde özel kesitli filament iplikler mukavemet, kopma uzama, düzgünsüzlük, kaynama çekme testleriyle karakterize edilmiştir. Dairesel ve yassı kesitli iplikler daha kararlı üretim performansı göstermiştir. Tezin son kısmında ise üretilen tüm ipliklerin hidrolitik ve termal bozunma davranışları hızlandırılmış şartlandırma testiyle karakterize edilmiştir. Referans olması bakımından dairesel kesitli Poli Etilen Teraftalat (PET) ipliği kullanılmıştır. Şartlandırma testi koşulları, 12 haftalık zaman diliminde filament ipliklerin 58°C±2°C, %50 bağıl neme maruz tutulması olarak uygulanmıştır. Şartlandırma testi, viskozite, karboksil, mukavemet, DSC ve SEM analizleriyle karakterize edilmiştir. Test sonuçları analiz edildiğinde özellikle PDLA katkısının ve artı/üçgen kesit şekilllerinin termal/hidrolitik bozunmayı arttırdığı ve tüm PLA ipliklerinin referans alınan PET ipliğine göre çok daha fazla termal/hidrolitik bozunmaya uğradığı tespit edilmiştir.
In this thesis, Poly L Lactic Acid (PLLA) filament yarns with modified/developed structure were produced by using additives and using special section spinnerets. Poly D Lactic Acid (PDLA) was used as additive, and triangular, plus, hollow circle, flat section spinnerets were used as special spinnerets. The aims of these study are; improving the yarn production performance by reducing the hard-brittle structure of the PLLA polymer, increasing the ductility of PLLA filament yarns by accelerating the thermal and hydrolytic degradation without deteriorating the physical properties of the product, indirectly improving the slow biodegradation property which is seen as one of the biggest disadvantages of PLLA. In the first part of the thesis, PLLA blends with PDLA (3%, 6%, 9%) were produced in the extrusion process. Then, FDY (full drawn yarn) filament yarns were produced from these blends using the same spinning parameters in a pilot scale machine. While the blends were characterized by viscosity, carboxyl, ash and DSC tests, filament yarns were characterized by viscosity, carboxyl, tensile, elongation at break, unevenness, boiling shrinkage and DSC tests. It has been determined that the PDLA additive significantly reduces the % crystallinity value in both blends and filament yarns. In the second part of the thesis, special cross sections of filament yarns were produced from PLLA polymer. Triangle, plus, hollow circle, flat cross sections are used as a special section, while circular section is used as a reference. By using the same spinning parameters, FDY filament yarns with special cross-sections were produced and then characterized by tensile, elongation at break, unevenness, boiling shrinkage tests. Circular and flat cross-section yarns showed more stable production performance. In the last part of the thesis, hydrolytic and thermal degradation behaviors of all yarns produced were characterized by accelerated conditioning test. For reference, circular cross-section Poly Ethylene Terephthalate (PET) yarn was used. Conditioning test were applied as exposing filament yarns to 58°C ± 2°C, 50% relative humidity over a twelve-week period. The conditioning test was characterized by viscosity, carboxyl, tensile, DSC and SEM analysis. When the test results were analyzed, it was determined that especially the PDLA additive and plus/triangle cross-section shapes increased the thermal/hydrolytic degradation and all PLA filament yarns were subjected to much more thermal/hydrolytic degradation than the reference PET yarn.
In this thesis, Poly L Lactic Acid (PLLA) filament yarns with modified/developed structure were produced by using additives and using special section spinnerets. Poly D Lactic Acid (PDLA) was used as additive, and triangular, plus, hollow circle, flat section spinnerets were used as special spinnerets. The aims of these study are; improving the yarn production performance by reducing the hard-brittle structure of the PLLA polymer, increasing the ductility of PLLA filament yarns by accelerating the thermal and hydrolytic degradation without deteriorating the physical properties of the product, indirectly improving the slow biodegradation property which is seen as one of the biggest disadvantages of PLLA. In the first part of the thesis, PLLA blends with PDLA (3%, 6%, 9%) were produced in the extrusion process. Then, FDY (full drawn yarn) filament yarns were produced from these blends using the same spinning parameters in a pilot scale machine. While the blends were characterized by viscosity, carboxyl, ash and DSC tests, filament yarns were characterized by viscosity, carboxyl, tensile, elongation at break, unevenness, boiling shrinkage and DSC tests. It has been determined that the PDLA additive significantly reduces the % crystallinity value in both blends and filament yarns. In the second part of the thesis, special cross sections of filament yarns were produced from PLLA polymer. Triangle, plus, hollow circle, flat cross sections are used as a special section, while circular section is used as a reference. By using the same spinning parameters, FDY filament yarns with special cross-sections were produced and then characterized by tensile, elongation at break, unevenness, boiling shrinkage tests. Circular and flat cross-section yarns showed more stable production performance. In the last part of the thesis, hydrolytic and thermal degradation behaviors of all yarns produced were characterized by accelerated conditioning test. For reference, circular cross-section Poly Ethylene Terephthalate (PET) yarn was used. Conditioning test were applied as exposing filament yarns to 58°C ± 2°C, 50% relative humidity over a twelve-week period. The conditioning test was characterized by viscosity, carboxyl, tensile, DSC and SEM analysis. When the test results were analyzed, it was determined that especially the PDLA additive and plus/triangle cross-section shapes increased the thermal/hydrolytic degradation and all PLA filament yarns were subjected to much more thermal/hydrolytic degradation than the reference PET yarn.
Açıklama
Anahtar Kelimeler
Sustainability, PLA, Filament Yarn, Hydrolytic and Thermal Degradation, Sürdürülebilirlik, PLA, Filament iplik, Hidrolitik ve Termal Bozunma
