The role of thermal treatment on themorphology and phase behaviour ofhigh hard block content thermoplastic polyurethanes
Başlık çevirisi mevcut değil.
- Tez No: 715413
- Danışmanlar: Belirtilmemiş.
- Tez Türü: Yüksek Lisans
- Konular: Metalurji Mühendisliği, Metallurgical Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2017
- Dil: İngilizce
- Üniversite: The University of Manchester
- Enstitü: Yurtdışı Enstitü
- Ana Bilim Dalı: Belirtilmemiş.
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 101
Özet
Özet yok.
Özet (Çeviri)
Thermoplastic polyurethanes (TPUs) are defined as linear di-block copolymers consisting of statistically-alternating hard segments (HS) and soft segments (SS). Due to their various application areas, considerable attention has been aroused to these materials. The excellent properties of TPUs are generally ascribed to their microphase-separated nature resulting from the thermodynamic incompatibility between hard segments and soft segments. The effect of different thermal treatments (melt-quenched, isothermally annealed) on the micro phase separation, crystallinity and mechanical properties of the 70 % HS (w/w) TPUs has been investigated. The SS was based on poly(propylene oxide), end capped with ethylene oxide (EO-PPO-EO), and the HS on a 4,4'-methylene diphenyldiisocyanate (MDI) chain extended by 1,5-pentanediol (15PD). By correlating the TGA results with GPC results, it has been concluded that no considerable degradation was presented by our samples. Two high temperature melting endotherms were observed on the DSC thermographs of the meltquenched samples. Lower temperature endotherm was attributed to melting of the crystallites residing on the HS, while higher temperature endotherm was considered to belong to the microphase mixing of the two segments. High temperature endotherms of the melt-quenched samples shifted to higher temperatures upon annealing suggesting increased phase separation due to annealing process. DMTA experiments provided further support to this interpretation by indicating that young modulus and HS glass transition temperature (𝑇𝑔𝐻𝑆) of the melt quenched samples was increased by annealing due to better phase separation. Increased mechanical properties by annealing were also observed on the tensile testing. FTIR measurements provide evidence that the increase in the 𝑇𝑔𝐻𝑆 of the melt quenched sample due to annealing was not caused by the increase in the strength of the hydrogen bonding. WAXS spectrum of the melt-quenched sample revealed that these materials were amorphous. Crystallinity of these materials was seen to have increased by annealing and positive correlation was found between the annealing time and the extent of crystallinity.
Benzer Tezler
- Kömürün mineral içeriğinin yanma özelliklerine etkisi
The Effect of mineral matter content of coal on its combustion properties
HANZADE AÇMA
- Mikro ark oksidasyon işlemi uygulanmış silisyum karbür takviyeli az91d magnezyum alaşımının korozyon ve aşınma özelliklerinin incelenmesi
Investigation on wear and corrosion properties of micro arc oxidized sic reinforced az91d magnesium alloy
MEHMET RAGIP MUHAFFEL
Yüksek Lisans
Türkçe
2012
Metalurji Mühendisliğiİstanbul Teknik ÜniversitesiMetalurji ve Makine Mühendisliği Ana Bilim Dalı
PROF. DR. HÜSEYİN ÇİMENOĞLU
- Yüzey işlemleri öncesi cam yüzeyine uygulanan çözeltilerin etkileri
Effects of solutions applied to the glass surface before surface treatment
SEMİN CANBAZOĞLU
- Soğuk sprey eklemeli imalat yöntemiyle üretilen ınconel 718 süperalaşımının yüzey özelliklerine kutu alüminyumlama işleminin etkisi
Effect of pack aluminizing process on surface properties of inconel 718 superalloy produced by cold spray additive manufacturing
OSMAN KAHRAMAN
Yüksek Lisans
Türkçe
2024
Metalurji Mühendisliğiİstanbul Teknik ÜniversitesiMetalurji ve Malzeme Mühendisliği Ana Bilim Dalı
PROF. DR. MURAT BAYDOĞAN
- Isıl olarak yeniden düzenlenmiş polimer membranlarla gaz ayırma
Gas separation by thermally rearranged polymer membranes
FATİH DURAK
Yüksek Lisans
Türkçe
2016
Kimya Mühendisliğiİstanbul ÜniversitesiKimya Mühendisliği Ana Bilim Dalı
YRD. DOÇ. MEHTAP ŞAFAK BOROĞLU