이타콘산 기반 고흡수성 수지의 합성 및 특징

Abstract

본 논문은 환경 친화적 소재인 이타콘산을 이용한 고흡수성 수지 (super absorbent polymer, SAP) 합성에 관한 논문이다. 이타콘산과 비닐 술폰산의 공중합체에 카올린을 투입한 SAP 복합체를 제조하는 것이다. 카올린은 SAP 공중합체와 수소결합 등의 물리적인 상호작용을 통하여 겔 강도를 향상시키는 데 효과가 있는 것으로 알려져 있다. 중합은 이타콘산과 공단량체를 중화시킨 뒤 내부 가교제, 카올린, 열 개시제를 순차적으로 투입한 수용액 라디칼 중합법을 이용하였다. 제조된 SAP 복합체의 구조는 ATR-FTIR 및 XRD를 통해 분석하였고, SEM을 통해 SAP의 모폴로지를 관찰하였다. 이전 연구에서 도출한 최적 공단량체 비율인 이타콘산 대 비닐 술폰산 7:3을 적용하여 중합 온도, 중화도, 개시제 종류 및 함량, 내부 가교제 종류 및 함량, 카올린 함량 등의 요인이 SAP 복합체 성능에 미치는 영향을 고찰하였다. SAP 복합체의 성능은 보수능 (centrifuge retention capacity, CRC), 가압흡수능 (absorbency under load, AUL)을 측정하였다. 추가적으로 수가용 성분 측정을 통해 중합 온도가 SAP의 가교체 형성에 미치는 영향을 확인하였고, 내부가교제 종류 및 함량에 따른 탈수율을 측정하여 내부 가교밀도에 미치는 영향을 확인하였다.|Superabsorbent polymer (SAP) can absorb and retain water more than several ten times of their dry mass due to their three-dimensional hydrophilic structure. Many studies on the bio-based materials have been conducted. Kaolin was added to the copolymer of itaconic acid (IA) and vinyl sulfonic acid (VSA) to improve SAP properties such as centrifuge retention capacity (CRC), and absorbency under load (AUL). The polymerization was carried out by aqueous solution radical polymerization where IA and VSA were neutralized and then a crosslinker, kaolin and a thermal initiator were added in sequence. The structure of SAP composites was characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction analysis (XRD). Also, we observed the morphologies of the SAP composites using scanning electro microscope (SEM). We studied the changes of absorption properties of the SAP composites according to the polymerization temperature, degree of neutralization, type and content of initiator, type and content of inner-crosslinker, and kaolin content. As a result, we could investigate the effects of some synthetic factors on the absorption properties of the SAP composite.; Superabsorbent polymer (SAP) can absorb and retain water more than several ten times of their dry mass due to their three-dimensional hydrophilic structure. Many studies on the bio-based materials have been conducted. Kaolin was added to the copolymer of itaconic acid (IA) and vinyl sulfonic acid (VSA) to improve SAP properties such as centrifuge retention capacity (CRC), and absorbency under load (AUL). The polymerization was carried out by aqueous solution radical polymerization where IA and VSA were neutralized and then a crosslinker, kaolin and a thermal initiator were added in sequence. The structure of SAP composites was characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction analysis (XRD). Also, we observed the morphologies of the SAP composites using scanning electro microscope (SEM). We studied the changes of absorption properties of the SAP composites according to the polymerization temperature, degree of neutralization, type and content of initiator, type and content of inner-crosslinker, and kaolin content. As a result, we could investigate the effects of some synthetic factors on the absorption properties of the SAP composite.