4,4'-Methylene bis(o-chloroaniline)과 1,3-propanediol bis(p-aminobenzoate) 가교제를 사용한 폴리우레탄 코팅필름과 열가소성 탄성체의 제조와 특성 비교 연구

김정기 全北大學校 2005 국내박사

Polyurethane is a versatile polymeric material, which can be tailored to meet diversified demands of modern technologies, such as coatings, adhesives, reaction molding plastics, fibers, foams, rubbers, thermoplastic elastomers, and composites. Elastomeric polyurethanes are usually prepared from polyol, diisocyanate, and diol or diamine as a crosslinking agent, and they exhibit various properties, depending on the chemical structure and ratios of the compositions. Effects of various factors on properties of polyurethanes have been extensively studied and well known. 4,4'-Methylene bis(o-chloroaniline)(MOCA) has been widely used as a crosslinking agent, but classified as a toxic chemical. Thus, its use will be limited in the near future. However, effects of alternatives of MOCA on properties of polyurethans have not been reported in detail in the literature. In this research, polyurethane coating films and thermoplastic polyurethanes(TPU) were prepared using 1.3-propanediol bis(p-aminobenzoate)(PDBA) as an alternative to MOCA. Their pot life, thermal stability and mechanical properties were investigated in order to find out an optimum recipe to be utilized easily in the field of polyurethane manufacturing. The base parts of polyurethane coatings were prepared by melting MOCA or PDBA in polyoxypropylene(Mn=2000), followed by the addition of the various additives. The NCO-terminated toluene diisocyanate prepolymer was used as a curing agent. The polyurethane coating films were prepared by mixing the base part with the curing agent in an appropriate ratio at room temperature. The polyurethane coatings prepared using PDBA exhibited higher initial viscosity, but much longer pot life, compared to those prepared using MOCA under the same conditions, due to lower reactivity of PDBA. The tensile strength and tear strength of the coating films were much weaker. However, the pot life, tensile strength, elongation, and tear strength of the coating films, prepared using PDBA in the presence of an increased amount of catalyst, were close to those of the coating films prepared using MOCA. The prepolymer of TPU was prepared with poly(tetramethylene ether)glycol, 4,4'-methylene bis(phenyl isocyanate) (MDI) and 1,4-butanediol. TPU was prepared by mixing prepolymer with the crosslinking agent, MOCA, PDBA, in different ratios. The experimental results of TGA and DSC of TPUs prepared using PDBA were very close to those of TPUs prepared using MOCA. The elongation of TPU prepared using PDBA was silimar to that of TPU prepared using MOCA, but the tensile strength of TPU prepared from PDBA was greater than that of TPU prepared from MOCA. Thus, it can be concluded that PDBA, which is environmentally much more friendly, can substitute toxic MOCA in the preparation of polyurethane coatings and TPUs as long as the reactivity of PDBA is enhanced using appropriate amounts of catalyst or appropriate feed ratios of components are used.

Synthesis and Mechanical Properties of Water-soluble Polyurethane

임기영 대진대학교 대학원 2005 국내석사

수용성폴리우레탄은 사용하는 폴리올, 이소시아네이트, 촉매 및 사슬 연장제에 따라서 매우 다른 물성을 갖는다. 일반적으로 폴리올에 의한 유연한 물성과 이소시아네이트에 의한 경직된 물성으로 폴리우레탄의 물성이 결정된다. 경직된 물성을 나타내는 hard segment는 사용하는 사슬연장제에 따라 우레탄 및 우레아 결합을 형성하게 된다. 따라서 본 논문에서는 사슬 연장제로서 물을 사용하여 우레탄과 우레아 결합을 갖게 하여 경직된 rigidness를 갖는 수용성폴리우레탄을 합성하고자 하였다. 기계적 특성이 우수하고 내화학성을 갖는 수용성폴리우레탄 소재를 만들기 위하여 물을 함유한 폴리프로필렌 글리콜과 이소시아네이트를 사용하여 고기능성 수용성폴리우레탄을 합성하였다. 합성시 발현하는 반응을 파악하기 위하여 반응시의 Free NCO의 함량의 변화를 측정하였으며 합성된 폴리우레탄을 필름화하여 FT-IR spectra를 사용하여 우레탄 및 우레아에 의한 특성 스펙트럼을 확인함으로서 합성된 폴리우레탄의 구조를 파악하고자 하였다. 또한 물의 함량과 사용 폴리올과 이소시아네이트의 당량비에 따른 합성 폴리우레탄의 열적성질, 흐름특성, 그리고 기계적 특성을 고찰하였다. Water-soluble polyurethane is the most versatile class of polymers for the coating and leather material. Water-soluble polyurethane need to have chemical stability and good mechanical property. In this study, high performance water-soluble polyurethane was synthesis by water containing and isocyanate. Water in PPG is used as the chain extender to produce urea link. The structure of synthesized water-soluble polyurethane was identified by FT-IR spectra and push-pull scale and water content. Self-levelling ability and mechanical properties were also investigated. It has been found that water in PPG caused the formation of urea link which provide the rigid property of water-soluble polyurethane. Urea links are more pronounced with increasing NCO/OH ratio and water content. Hydrogen bonding between soft segment and rigid segment were dissosiated and reacted free NCO in urethane. Viscosity was become more densely increasing with water content and NCO/OH ratio. In high ratio of NCO/OH, the modulus and tensile strength was dramticaly increased.

Synthesis and Characterization of Highly Flexible Polyurethane Crosslinked with Slide-ring Polyrotaxane Composed of Poly(propylene glycol)-methyl-β-cyclodextrin

이지현 부산대학교 대학원 2023 국내석사

Highly stretchable low covered movable slide-ring polymer was synthesized by crosslinking poly(propylene glycol)-methyl-β-cyclodextrin polyrotaxane with diisocyanate. β-Cyclodextrin is capable of forming an inclusion complex with poly(propylene glycol) (PPG), the complex formed by the interaction between methyl-β-cyclodextrin (Me-β-CD) and PPG exhibits temperature-dependent phase transitions. Low covered methylated polyrotaxane was pre-synthesized from Me-β-CD and PPG. The incorporation of polyrotaxane into polyurethane endows it with high elongation properties, thanks to the slide-ring structure of the polyrotaxane. The slide ring movement of crosslinked Me-β-CD on polyurethane backbone allows to stretch without deformation. Low-covered polyrotaxane presents an opportunity for polyurethane to achieve outstanding elongation properties by enabling easier movement of ring-shaped molecules along the slip chains compared to the full-covered polyrotaxane. This innovative slide-ring structure polyurethane offers versatile applications in diverse industries such as biomedical devices, displays, and electronic materials. The low covered polyrotaxane was characterized by FT-IR, 1H-NMR and UV-vis spectroscopies. The molecular weight and crystal structure were measured by GPC and XRD, respectively. The polyurethane was characterized by FT-IR, DSC, and TGA. In addition, and the elongation of polyurethane according to the content of polyrotaxane was shown using Universal Tasting machine (UTM).

Polydimethylsiloxane (PDMS) 기반의 수분산 폴리우레탄 코팅제 합성 및 특성 연구

배은혜 부산대학교 대학원 2023 국내석사

여름철 북극항로의 개방으로 신규 극지 운항 선박 또는 극지 해양플랜트의 수요가 증가하고 있다. 그렇기에 기존의 케이블은 -40℃ 정도의 저온 특성을 필요로 하였으나 더 극한 환경에서 운항하는 선박이 늘어남에 따라 극지 운항 선박에 사용되는 케이블은 최대 -60℃ 수준에서 유연성을 유지하는 저온 특성이 요구되고 있다. 본 연구에서는 polyol로 polyether polyol type인 poly(tetramethylene ether glycol) (PTMG)와 기능성 polyol로 저온특성과 유연성, 내수성이 우수한 polydimethylsiloxane (PDMS)를 혼합하여 사용하였으며 isocyanate로 isophorone diisocyanate를 사용하여 수분산 폴리우레탄 코팅 수지 (SWPU)를 합성하였다. 그리고 필름을 제조하여 그 특성을 분석하였다. FT-IR과 XRD, PSA를 통해 SWPU의 기본적인 화학구조와 결정 구조, 그리고 입자 크기를 분석하였고 그 결과 합성이 잘 이루어졌음을 확인하였다. 또한 TGA, DSC, DMA 분석을 통해 PDMS의 함량이 증가함에 따라 열적 특성이 향상되었음을 확인하였고 SWPU-2에서 제일 낮은 Tg를 갖는 것을 알 수 있었다. UTM을 이용하여 기계적 특성을 평가하였고 SWPU-2에서 제일 높은 강도와 연신율을 갖는 것을 확인하였다. 접촉각을 통해 표면 특성을 분석하였고 증류수와 해수에서의 팽윤비를 분석하여 PDMS의 함량이 증가함에 따라 접촉각이 증가하고, 팽윤비는 감소하였음을 확인하였다. 수분산 폴리우레탄 (SWPU)의 특성 분석을 통해 PDMS가 우수한 저온특성, 유연성, 내수성을 부여할 수 있음을 나타내었다. 또한 인장강도와 신장율, DMA, DSC 분석을 고려하였을 때 PTMG와 PDMS의 몰비가 1.495 : 0.005인 SWPU-2에서 최적의 특성을 가진다고 할 수 있다. With the opening of the Northern Sea Route in summer, the demand for new polar vessels or polar offshore plants is increasing. Therefore, the existing cables required low-temperature characteristics of about -40°C, but as the number of ships operating in more extreme environments increases, cables used for polar-operated ships are required to have low-temperature characteristics that maintain flexibility at a maximum level of –60°C. In this study, poly(tetramethylene ether glycol) (PTMG), a polyether polyol type, and polydimethylsiloxane (PDMS), which have excellent low-temperature characteristics, flexibility, and water resistance, were used as a functional polyol. Then, waterborne polyurethane coating resin (SWPU) was synthesized using isophorone diisocyanate as isocyanate. Then, a film was prepared and its properties were analyzed. The basic chemical structure, crystal structure, and particle size of SWPU were analyzed through FT-IR, XRD, and PSA, and as a result, it was confirmed that the synthesis was successful. In addition, through TGA, DSC, and DMA analysis, it was confirmed that the thermal properties were improved as the content of PDMS increased, and it was found that SWPU-2 had the lowest Tg. The mechanical properties were evaluated using UTM, and it was confirmed that SWPU-2 had the highest strength and elongation. The surface properties were analyzed through the contact angle, and the swelling ratio in distilled water and seawater was analyzed to confirm that the contact angle increased and the swelling ratio decreased as the content of PDMS increased. Through characterization of waterborne polyurethane (SWPU), it was shown that PDMS can impart excellent low-temperature properties, flexibility, and water resistance. In addition, considering the tensile strength, elongation, DMA, and DSC analysis, SWPU-2 with a molar ratio of PTMG and PDMS of 1.495 : 0.005 shows the best characteristics.

환경친화적 발포제를 이용해 합성한 폴리우레탄 폼의 기계적 강도, 열적 거동 및 모폴로지에 관한 연구

최건형 연세대학교 2004 국내박사

환경친화적인 발포제를 이용한 초저온용 폴리우레탄 단열재 시스템을 개발하기 위해 HFC-365mfc 및 물과 시클로펜탄(cyclopentane)을 발포제로 사용하여 폴리우레탄 폼을 합성하였다. 원료물질이 폴리우레탄 폼의 물성에 미치는 영향을 관찰하기위해 각각의 발포제와 원료물질을 변화시키며 합성한 폴리우레탄 폼의 기계적 강도와 열적거동 및 모폴로지에 관한 연구를 수행하였다. 합성된 폴리우레탄 폼의 열적거동 및 모폴로지는 시차주사열분석기(Differential Scanning Calorimeter, DSC), 열전도도 측정기(Thermal Conductivity Meter), 적외선분광분석기(Fourier Transform Infrared Spectrometer, FT-IR), 주사전자현미경(Scanning Electron Microscope, SEM)을 이용하여 측정하였다. 기계적 강도는 초저온 챔버가 부착된 만능시험기(Universal testing machine, UTM)를 이용하여 측정하였으며 난연성은 ASTM 방법에 따라 특별히 제작된 난연성 측정장치를 이용하여 측정하였다. 화학적 발포제인 물을 발포제로 사용하여 합성된 폴리우레탄 폼의 경우 하나의 유리전이온도(Tg)만을 관찰할 수 있었다. 이를 통하여 합성된 폴리우레탄 폼이 연질 폴리우레탄 폼과는 달리 수소결합의 강도에 기인한 상 분리된 구조가 아닌, 가교구조를 형성하고 있는 구조임을 확인할 수 있었다. 또한 하드 세그먼트의 함량이 43%에서 83%로 증가할 수 록 유리전이온도도 54.2 ℃에서 118 ℃로 증가하였으며, 이는 제조된 경질 폴리우레탄이 가교구조임을 확인시켜주는 결과이다. 화학적 발포제인 물의 첨가량이 증가할수록 가교도 상승과 우레아 형성으로 인하여 유리전이온도가 증가하여 합성된 폴리우레탄 폼의 기계적 물성이 향상됨을 확인하였다. 계면활성제가 폴리우레탄 폼에 미치는 영향을 파악하기 위해 계면활성제의 양을 변화시켜 폼의 물성을 측정하였다. 계면활성제의 양이 0 php에서 3 php로 증가함에 따라 유리전이온도는 88 ℃에서 81 ℃로 감소하였고, 압축강도는 0.7 Mpa에서 증가하다가 최대치 1.7 Mpa을 나타낸 후, 다시 1.4 Mpa로 안정화되었다. 이는 계면활성제가 기포안정제로서 작용함과 동시에 가교도의 감소를 일으키는 것이 아니라 유연성을 부여하는 역할을 한다는 것을 알 수 있었다. 계면활성제는 단열재의 셀을 작고 균일하게 형성되도록 도와주기 때문에 셀 구조의 조밀성을 확인할 수 있었으며 실험에 의해 최적의 계면활성제 함량이 0.33 php 임을 확인하였다. 촉매에 따른 영향을 규명하기위해 서로 다른 구조를 갖는 촉매를 사용하여 촉매의 종류와 양에 따른 반응 속도 및 생성된 폼의 물성변화를 측정하였다. 촉매의 양이 증가하게 되면 발포 반응과 겔화반응이 모두가 빨라진다는 것을 알 수 있었으며 화학적 발포제인 물의 양이 증가하게 되면 물과 이소시아네이트의 우레아 형성반응이 급격히 진행되고 반응열의 증가로 인하여 발포반응의 속도가 빨라진다는 것을 알 수 있었다. 화학적 발포제를 사용한 경우 촉매에 따른 반응시간의 변화가 생성된 폼의 강도에 큰 영향을 미치지 않았으나 물리적 발포제를 사용한 경우에는 촉매의 양이 증가함에 따라 기계적 강도가 증가하는 결과를 나타내었다. 이는 촉매량의 증가에 따른 반응속도의 증가가 기공을 미세하게 하여 폼에 가해지는 하중을 분산시키기 때문임을 SEM을 통하여 확인하였다. 뿐만 아니라 촉매의 첨가량 증가에 따른 미세 기공의 형성으로 인해 폴리우레탄 폼의 열전도도도 향상시킬 수 있음을 확인하였다. 폴리올이 폴리우레탄 폼의 물성에 미치는 영향을 파악하기 위하여 물리적 발포제인 HFC-365mfc를 사용한 시스템에서 폴리올의 작용기와 수산가를 변화시키며 폴리우레탄 폼을 합성하였다. 플라스틱 폼에서 압축강도는 밀도의 함수로 알려져 있다. 그러나 본 연구 결과에서는 동일밀도에서도 폴리올의 수산가와 작용기가 각각 290, 3에서 400, 4 그리고 450, 4∼5로 증가함에 따라 폴리우레탄 폼의 압축강도가 각각 8.4에서 9.7, 13.2 kgf㎠로 증가하는 경향을 나타내었다. 수산가와 작용기에 따른 기계적 물성의 증가가 가교도의 상승에 기인함을 확인하기 위해 Tg를 측정한 결과 수산가와 작용기가 290, 3에서 400, 4 그리고 450, 4∼5로 증가함에 따라 Tg는 63 ℃에서 129 ℃, 162 ℃로 증가함을 확인하였다. 이는 수산가와 작용기가 증가하면 폴리우레탄 폼의 가교도가 증가됨을 의미한다. 따라서 밀도뿐만 아니라 폴리올의 작용기와 수산가에 의한 가교도의 증감이 폴리우레탄 폼의 기계적 물성에 많은 영향을 끼치는 중요한 인자임을 확인하였다. 화학적 발포제를 사용하여 합성된 폴리우레탄 폼의 경우에도 폴리올의 수산가와 작용기가 증가할수록 압축강도와 Tg가 증가하는 경향을 나타내었으나 물리적 발포제를 사용한 것과 같은 큰 변화를 나타내지는 않았다. 이는 물을 발포제로 사용한 경우 물과 이소시아네이트의 초기 반응이 폴리올과 이소시아네이트의 반응에 의한 영향을 상쇄시켜 작용기와 수산가 변화에 따른 영향이 크게 나타나지 않기 때문이다. 따라서 화학적 발포제를 사용하여 제조된 폴리우레탄 폼은 물리적 발포제를 사용하여 합성된 폼과는 달리 폴리올의 작용기와 수산가에 의한 가교도의 증감이 폼의 기계적 물성에 큰 영향을 끼치지 않음을 확인하였다. NCO Index가 증가함에 따라 폼의 밀도와 압축강도가 증가하였고 NCO Index는 120 정도에서 가장 안정한 물성을 지니는 폴리우레탄 폼을 단열재를 합성할 수 있음을 실험적으로 확인하였다. The purpose of this study was to develop a cryogenic insulation system using environment-friendly blowing agents. Polyurethane foams were manufactured using cyclopentane, water, and HFC-365mfc as the blowing agents. The mechanical properties, thermal behavior, and morphology of the agents were then closely studied and compared. Additionally, the effects of the physical properties of the polyurethane foams on the characteristics of the raw materials used were studied in an effort to improve insulating efficiency and mechanical properties. Polyurethanes were synthesized using the 4,4''-diphenylmethane diisocyanate (PMDI), polyether polyol, and 1,4-butane diol. Thermal behavior and morphology were measured by a differential scanning calorimeter (DSC), thermal conductivity meter, fourier transform infrared spectrometer (FT-IR), and scanning electron microscope (SEM). Mechanical properties were measured by universal testing machine (UTM), utilizing various testing jigs and a cryogenic chamber. When examining rigid polyurethane foams prepared from distilled water as a chemical blowing agent, the glass transition temperature (Tg) was found to be related to the crosslinking density, but not to the strength of hydrogen bonding. Additionally, as the amount of hard segment was increased from 43 percent to 83 percent, the Tg rose from 54.2 ℃ to 118 ℃. This result meant that the main structure of the polyurethane was crosslinking. As the amount of distilled water was increased, the Tg rose, owing to the accrual of crosslinking and the formation of urea. As well, the raised value of the Tg resulted in an improvement of the mechanical properties of the PUF. It was found that the amount of the surfactant added as a plasticizer had no significant influence on the density of the PUF. It was also revealed that the mechanical strength of the PUF rose as the content of the surfactant increased. This can be explained because the properties of the surfactant play a role in making the cell structure smaller and more uniform. Further observations reveal that the cream time and gel time shorten if the catalysts content increase. The kinetic rate of PUF forming expands with the rise of distilled water as a chemical blowing agent. This is attributed to an increase of heat in the reaction. When larger amounts of catalysts are used, the cell size of the PUF decreases because the rate of blowing gas formation amplifies. From this study, the effect of mixed polyol on the physical properties of PUF was determined. A PUF insulation with excellent physical properties and thermal behavior can be synthesized within a range of 400~460 of the OH value of mixed polyol. If cyclopentane is exclusively used as the blowing agent, it is found that the synthetic PUF becomes unstable, producing internal cracks. This results in nonuniform blowing because of the temperature sensitivity of the reactants. As the NCO Index was increased, the density and compressive strength of the PUF insulation rose. It was established that the most chemically stable PUF insulation is manufactured at 120 on the NCO Index. The effects of individual blowing agents (CFC-11, HCFC-141b, and HFC-365mfc) on PUF synthetics were evaluated and the possibility of substitution as an environment-friendly blowing agent was investigated. As the OH value and functionality of polyol were increased, the density, compressive strength, and Tg rose as well. As well, there was an observable decrease in cell size. The quantity and type of catalysts used had no significant influence on the Tg, but resulted in a heightening of the mechanical strength. The PUF synthesized with using HFC-365mfc as the blowing agent showed similar characteristics to the existing PUF synthesized with using CFC-11 or HCFC-141b in kinetic rate, reaction temperature, mechanical properties, thermal behavior, and cell morphology. Thus, after careful experimentation, calculation, and comparison, the results of this study put forth the possibility of an alternative, environment-friendly blowing agent.

Synthesis and Characterization of Polyrotaxane-based Polyurethane with Improved Mechanical Strength and Elongation

곽수민 부산대학교 대학원 2023 국내석사

Highly stretchable polymers have gotten much attention due to a wide range of applications including biomedical materials, automobiles, etc. Because of slide-ring structure, polyrotaxane has been frequently used to endow polymers with stretchability. In this study, polyrotaxane was used as a chain extender of polyurethane to improve both tensile strength and elongation. Highly stretchable polymer synthesized by crosslinking polyurethane with pre-synthesized polyrotaxane consists of polypropylene glycol (PPG) with low-covered cyclodextrin (CD) which acts as chain extender and crosslinker, respectively. Polyrotaxane was synthesized by threading beta cyclodextrin (β-CD) along the axis of PPG-diamine polymer backbone, followed by end-capped with 2,4,6-trinitrobenzene sulfonic acid (TNBS). The synthesized polyurethane and polyrotaxane were characterized by 1H-NMR and FT-IR spectroscopies. The coverage of cyclodextrin on polyrotaxane was adjusted by the mole ratio of PPG and β-CD. DSC and TGA were used to characterize thermal properties of polyurethane. A tensile test was also conducted to measure tensile strength and elongation. DMA was used to characterize elasticity and crosslink density. As a result, an increase in the tensile strength and elongation of the polyrotaxane as the content of polyrotaxane increased was confirmed. This study suggests that polyurethane containing polyrotaxane can be used as a new class of highly stretchable polymers.

Highly Stretchable Polyurethane Elastomer Incorporating Slidable Polyrotaxane Crosslinker

이채준 부산대학교 대학원 2024 국내석사

The study focuses on enhancing the elasticity and strength of polyurethane using polyrotaxanes with a sliding-ring effect. Polyrotaxanes were employed to harness the host-guest interaction capability inherent in cyclodextrins for the encapsulation of poly(propylene) glycol, followed by end-capping using DMT-MM and N-(triphenylmethyl) glycine. The resulting polyrotaxane was them methylated by reacting with CH3I to adjust the hydroxyl group, and the resulting methylated polyrotaxane was used as a chain extender in the synthesis of polyurethane. The polyurethane thus produced allows for the sliding of crosslinking points, due to the presence of slidable methyl-beta cyclodextrin within the polyrotaxane. The synthesized polyrotaxane and its methylated one as well as slidable polyurethane methylated polyrotaxanes were characterized for their structural properties using FT-IR, 1H-NMR, and XRD, while their thermal properties were determined through DSC. The elongation and tensile strength of the polyurethane were assessed using UTM.

Vegetable Oil-based Hyperbranched Polymers as Eco-Friendly Precursors for Polyurethane

김호안 부산대학교 대학원 2020 국내석사

Hyperbranched polymer (HBP) and dendrimers are multi-branched, three–dimensional structured polymers with distinctive properties that are different from linear polymers. Our interest to use vegetable oils, which is a renewable raw material as an effective platform for the synthesis of HBP as green polyols. Unsaturated bonds containing soybean oil and hydroxyl groups containing castor oil are used for synthesizing of sustainable polyols. In the case of soybean oil based polyols, epoxidation and ring-opening reaction were carried out. HBP were synthesized via simple batch monomer addition polymerization of glycidol using heterogeneous double metal cyanide (DMC) catalysts. Vegetable oil-based HBP were successfully incorporated as a replacement for conventional polyols to produce flexible polyurethane foams. Increased Vegetable oil-based HBP in the mixture increased the rate of reaction and phase mixing due to the availability of primary hydroxyl groups. Polyurethane foams with the addition of vegetable oil-based HBP, the cell walls became thinner, the amount of broken cells increased and the cell size decreased. Polyurethane foams with vegetable oil-based HBP resulted in improvements of thermal properties. Densities of the resultant composites were increased as a result of increased vegetable oil-based HBP content. 하이퍼 브랜치 폴리머 (HBP) 및 덴드리머는 선형 폴리머와는 다른 독특한 특성을 갖는 다 분기 3차원 구조화 된 폴리머이다. 또한, HBP는 덴드리머보다 더 쉽게 제조 될 수있다. 따라서, 실용적인 관점에서, HBP는 덴드리머보다 더 유용 할 수 있다. 녹색 폴리올로서 HBP의 합성을 위한 효과적인 플랫폼으로서 재생 가능한 원료 인 식물성 오일을 사용하는 것에 대한 우리의 관심. 콩기름 및 피마 자유를 함유하는 히드록실기를 함유하는 불포화 결합은 지속 가능한 폴리올의 합성에 사용된다. 대두유 기반 폴리올의 경우, 에폭시화 및 개환 반응이 수행되었다. 이종 이중 금속 시안화물 (DMC) 촉매를 사용하여 글리시돌의 간단한 배치 단량체 첨가 중합을 통해 HBP를 합성하였다. 개시제로서 다양한 식물성오일을 사용하여 과분지형 중합체를 제조하기 위한 광범위한 연구가 수행되었다. 잠재 고리 형 AB2 형 단량체의 개환 다 분기 중합 (ROMBP)은 광범위한 폴리 글리시돌을 달성하기위한 주요 반응이다. 복잡한 거대 분자 구조로서 생성 된 중합체는 주변에 제어 가능한 수의 히드록 실기를 함유한다는 것을 고려하면, 신규 한 폴리우레탄의 설계 및 새로운 적용을 위한 생체 적합성 빌딩 블록에 유용한 녹색 원료가 될 수 있다. 플렉서블 폴리우레탄 폼을 제조하기 위해 식물성 오일 계 HBP가 통상적 인 폴리올의 대체물로서 성공적으로 통합되었다. 혼합물에서 식물성 오일-기반 HBP의 증가는 일차 하이드 록실 그룹의 이용 가능성으로 인해 반응 및 상 혼합 속도를 증가시켰다. 가교 결합 밀도를 증가시키는 하이퍼-브랜치 폴리머의 높은 기능성은 폴리우레탄의 열 특성을 향상시킨다. 식물성 오일-기반 HBP 함량이 증가함에 따라 생성 된 복합체의 밀도가 증가되었다. 주사 전자 현미경 (SEM)을 사용하여 형태를 조사 하였다. 식물성 유성 HBP 함량이 증가함에 따라, 세포 크기는 감소 하였다. 식물성 오일-기반 폴리올로부터 제조 된 폴리 우레탄 폼에 대한 많은 연구가 있지만, 식물성 오일-기반 고분 지형 폴리머로부터 제조 된 폴리 우레탄 폼에 대한 연구는 거의 없다. 본 연구는 바이오 폼을 제조하는 간단한 방법을 제공하는 한편, 합성 폴리올 대신에 식물성 오일을 성공적으로 사용하여 농업 자원에 가치를 부가 할 수있다.

글리콜 환경에서의 음향센서 몰딩재 사용수명예측 연구

박나영 금오공과대학교 대학원 2023 국내석사

본 연구는 음향센서를 보호하는 몰딩부인 폴리우레탄이 글리콜 환경에서 음향센서를 장기간 보관하여 사용하게 될 경우, 얼마의 수명을 갖는지 알아보는데 그 목적이 있다. 폴리우레탄이 글리콜에 장기간 노출되면 폴리우레탄의 soft segment와 hard segment 가 글리콜과 반응하여 가수분해 또는 글리콜 분해를 유발할 수 있다[1]. 따라서 글리콜 환경에서 수 십년 간 사용이 필요한 품목에 폴리우레탄을 적용하는 경우 사용 시 주의가 필요하다. 본 연구에서는 이러한 상황에 따라 기존 가속수명시험을 재설계 및 시험하여 가속 계수를 구하였으며, 시험을 통해 구한 가속 계수를 이용하여 음향센서부 사용 조건에서의 폴리우레탄 사용 수명을 계산하였다. 또한 폴리우레탄의 종류에 따라 폴리에스테르 우레탄(AU)과 폴리에테르 우레탄(EU)을 각각 시험하여 비교함으로써 폴리우레탄의 종류에 따른 글리콜 저항성 및 사용 수명을 알 수 있었으며, 글리콜 환경에서 사용할 소재를 선정할 때 고려해야 할 핵심요소도 추가로 확인할 수 있었다. The purpose of this study was to find out how long the molding part, polyurethane, that protects the acoustic sensor, will have a service life when the acoustic sensor is stored and used in a glycol environment for a long time. When polyurethane is exposed to glycol for a long time, the soft and hard segments of polyurethane may react with glycol, resulting in hydrolysis or glycolysis. Therefore, if polyurethane is applied to items that require decades of use in a glycol environment, caution is required when used. In this study, the acceleration factor was calculated by redesigning and testing the existing acceleration life test according to this situation, and the service life of polyurethane under the operating conditions of the acoustic sensor unit was calculated using the acceleration factor obtained through the test. In addition, by testing and comparing polyester and polyether urethane according to the type of polyurethane, glycol resistance and service life depending on the type of polyurethane were identified, and key factors to consider when selecting a material to be used in a glycol environment could be additionally confirmed.

나노 무기충전제 및 난연제 첨가 폴리우레탄 복합체의 제조 및 난연 특성

구동철 忠南大學校 2007 국내박사

In this study, to prepare polyurethanes composites of fine properties, PTMG(Polytetramethyleneglycol) and IPDI(Isoporonediisocyanate) were used with various additives which were divided inorganic filler into flame retardant. MMT, OLS(organo modificated layered MMT), silica and CaCO₃ were used as the inorganic fillers and Al(OH)₃, Bi₂O₃ and TCP as the flame retardants. Such prepared PU composites were determined by method of thermal, mechanical and retardant analysis according to the kind and content of additives. The structures and surface properties of such synthesized PU nanocomposites were confirmed by the measurement of FT-IR and X-ray diffraction, respectively. The result of XRD analysis showed that compared with d-spacing of pure CaCO₃, that of CaCO₃ after PU composites synthesis was enlarged about 1.49Å and that compared with d-spacing of pure Bi₂O₃, that after Bi₂O₃ PU composites synthesis was enlarged about 1.35Å. The result of FT-IR analysis showed that all peaks of NCO group was disappeared at 2270cm^(-1), it means that PU was synthesized The thermal stabilities of the PU nanocomposites were studied by using the TGA and DSC analysis. The thermal stabilities of nanocomposites were higher than that of the pure PU resin. Also, SEM photographs showed that most filler layers were dispersed homogeneously into the matrix polymer in nano-scale, although some particles of silica were agglomerated. UTM was used to examine mechanical properties which could determine tensile stength, elogation and tearing energy. As a result, it was observed that tensile strength of PU composites adding 2wt% silica increased about 2.5 times than that of pure PU. The result of elongation test showed that elongation of PU composites adding 2wt% silica increased about 1.5 times than that of pure PU. The result of tearing energy analysis confirmed that tearing energy value of PU composites with CaCO₃ or Al(OH)3 was most superior. The flame retardancy of polyurethane resin could be improved by addition of nano-scaled fillers. Limited oxygen index(L.O.I.) and corn calorimeter was used to thoroughly determine the flame retardancy of polyurethane nanocomposites systems according to the kind and the contents of vareous fillers and retardant. The L.O.I. values increased from flammable region (L.O.I.<19) to nonflammable region (L.O.I.>20), .in content more than 2wt% additives. Especially, PU composites compounded with polyurethane and hybrid(Bi₂O₃+MMT)additives was improved in flame retardancy better than that added other fillers or pure polyurethane resin. Summarizing the study result so far, thermal properties by TGA analysis confirmed that PU composites with Bi₂O₃ was most superior. Mechnical properties by UTM analysis confirmed that PU composites adding silica was most superior but inflammable properties confirmed that silica was worst. Therefore, this study showed that PU composites with hybrid (MMT+Bi₂O₃) satisfied all of mechanical properties and inflammable properties