Biodegradable Sol-gel Coatings of Waterborne Polyurethane/Gelatin Chemical Hybrids = 젤라틴 도입에 따른 수분산성 폴리우레탄의 물성 및 생분해능에 관한 연구

다국어 초록 (Multilingual Abstract)

Gelatin from cold fish skin has strong mechanical properties and biodegradability. Cold fish gelatin was introduced into waterborne polyurethane (WPU) by covalent bonding to reinforce and render biodegradability of WPU. For this, gelatin was chemically modified with vinyltrimethoxysilan (VTMS) via the sol-gel type reactions and incorporated into hydroxyl ethyl acrylate (HEA) termini of WPU by UV curing. Covalent incorporations provided the hybrids with enhanced water resistance, hardness, glassy and rubbery state moduli, yield strength, and thermal resistance of soft segment along with significantly enhanced biodegradability both in trypsin solution and soil.

다국어 초록 (Multilingual Abstract)

The alkyl acrylate copolymer (ACM) rubbers were synthesized and characterized. Various amounts of initiator, reducing agent etc were used at various temperatures to synthesize the rubbers. Ethyl acrylate (EA), butyl acrylate (BA), and methoxyethyl acrylate( MEA) were used as monomer and 2-chloroethyl acrylate as a functional monomer. Tetramethyl ethylene diamine (TMEDA) and potassium persulfate (KPS) were used as oxidant and reducing agent, respectively. The rate of polymerization (Rp) increased and the Mooney viscosity decreased with the increased amount of KPS. At low concentration of initiator (below 0.4 wt.% monomer), the ACM rubber wasn’t synthesized. According to the use of large amount of reducing agent, Rp increased clearly below five times as large as the amount of initiator. However, the use of very large amount of reducing agent (over ten times with initiator) lowered Rp . On the other hand, Rp increased and the Mooney viscosity decreased with the increased temperature.

목차 (Table of Contents)

• Chapter 1. Biodegradable sol-gel coatings of waterborne polyurethane/gelatin chemical hybrids
• 1.1 Abstract 1
• 1.2 Introduction 3
• 1.3 Experimental Section 5
• 1.3.1 Materials 5
• 1.3.2 Modification of gelatin 6
• 1.3.3 Synthesis of WPU and UV cure 6
• 1.3.4 Characterizations 7
• 1.4 Results and discussion 8
• 1.4.1 FT-IR measurements 8
• 1.4.2 Surface properties 8
• 1.4.3 Thermal properties 9
• 1.4.4 Dynamic mechanical and mechanical properties 11
• 1.4.5 Biodegradability 12
• 1.5 Conclusions 13
• 1.6 References 14
• Chapter 2. Synthesis and characteristic of alkyl acrylate copolymer in redox initiation systems by
• semibatch emulsion polymerization
• 2.1 Abstract 32
• 2.2 Introduction 34
• 2.3 Experimental Section 35
• 2.3.1 Materials 35
• 2.3.2 Polymerization 35
• 2.3.3 Characterizations 36
• 2.4 Results and discussion 37
• 2.4.1 Variation of initiator and reducing agent 37
• 2.4.2 Variation of reducing agent concentration 38
• 2.4.3 Variation of feed rate 39
• 2.4.4 Variation of temperature 39
• 2.4.5 Different method of input of initiator/reducing agent concentraton 40
• 2.4.6 Variation of emulsifier concentration 40
• 2.4.7 Variation of initiator/reducing agent at 8% emulsifier concentration 41
• 2.4.8 Variation of temperature at 8% emulsifier concentration 41
• 2.4.9 Variation of initiator/reducing agent and feed rate at 50 degree Celsius 42
• 2.4.10 Variation of feed rate at 30 degree Celsius 42
• 2.4.11 Excess concentration of emulsifier 43
• 2.5 Conclusions 43
• 2.6 References 45