Compatibilization of LDPE/PA6 by Using a LDPE Functionalized with a Maleinized Hyperbranched Polyester Polyol

Carlos A. Ararat,María Judith Percino,Edwin A. Murillo 한국고분자학회 2020 Macromolecular Research Vol.28 No.3

Low density polyethylene (LDPE)/polyamide6 (PA) blends can lead to a synergy between the properties of these materials. These blends are employed mainly in the packing industry, especially in food factories. The problem of this system is that it is inmiscible, hence requires to be compatibilized. The aim of this study is to compatibilize blends of LDPE/PA6 using a LDPE modified with a maleinized hyperbranched polyol polyester (LDPE-g-MHBP) as a compatibilizing agent. Therefore blends of LDPE (50 wt%)/PA (50 wt%) were prepared by using proportions of 5 (Blend5), 10 (Blend10), 15 (Blend15) and 20 (Blend20) wt% of the LDPE-g-MHBP of the total mix. On the other hand, to determine the efficiency of the LDPE-g-MHBP as a compatibilizing agent, a Blend0 (blends of LDPE (50 wt%)/PA (50 wt%) without LDPE-g-MHBP) was used as the control sample. By infrared (IR) analysis was evidenced the interactions between PA and LDPE-g-MHBP. By differential scanning calorimetry analysis (DSC) was observed that the LDPE-g-MHBP increased the crystallinity of the LDPE phase, but the behavior was opposite to PA. The thermal stability and the viscosity of the blends obtained with LDPE-g-MHBP were higher than those of the Blend0. Scanning electron microscopy (SEM) analysis revealed that the LDPE-g-MHBP ostensibly improved the miscibility of the LDPE/PA blends.

Effect of irradiation and LDPE content on crystal formation of PP

Prashanta Dahal(프러산터 다할),Youn Cheol Kim(김연철) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.6

전자선 조사 폴리프로필렌과 블랜드의 결정화 거동은 고분자 가공시 중요한 변수중 하나이다. 저밀도폴리에틸렌 (linear low density polyethylene, LDPE) 함량에 따라 폴리프로필렌(polypropylene, PP)/LDPE 블렌드를 이축압출기를 이용 하여 제조하였다. 조사에 의한 가교반응을 용이하게 하기위해 가교조제로 trimethylolpropane-trimetacrylate (TMPTMA)를 PP/LDPE 블렌드 제조시 첨가하였다. PP/LDPE 블랜드의 조사가교 효율에 대한 LDPE 함량의 영향을 평가하였다. 조사시료 의 비등온 결정화과정과 결정구조를 DSC, X-선회절분석(X-ray diffraction, XRD), 그리고 편광현미경(polarized optical microscope, POM)을 이용하여 분석하였다. 조사 후 시료의 용융온도가 감소하는 것은 조사에 의한 PP 사슬의 절단에 의한 것으로 판단된다. Ozawa 지수, n이 4일 때 구형, 3일 때 디스크형, 2일 때 로드형의 결정구조를 나타낸다. Ozawa 분석 결과, 순수 PP의 n 값은 3.8, 30 wt%의 LDPE를 포함하는 시료의 n은 2.3을 나타내었다. LDPE 첨가와 조사에 의해 PP의 결정구조 가 구형에서 disk나 rod형으로 변화하는 것을 Ozawa 분석과 POM을 통해 확인하였다. XRD 스펙트럼의 16.1o에서 나타나는 β 형 결정구조가 조사 후 시편에서 사라지는데, 이는 가교결합에 의한 것으로 해석할 수 있다. The crystallization behavior of irradiated polypropylene (PP) and the blend is an important parameter for polymer processing. Blends of PP/low density polyethylene (LDPE) with different LDPE contents were prepared by melt mixing in a twin screw extruder. The effect of the LDPE content on the irradiation effectiveness of the PP/LDPE blend with trimethylolpropane-trimetacrylate (TMPTMA) as a crosslinking co-agent was investigated in conjunction with the LDPE loading in the blend. The non-isothermal crystallization and crystal structure were measured by DSC, X-ray diffraction (XRD), and polarized optical microscopy (POM). A decrease in the melting temperature of PP was observed due to irradiation, which may be due to the PP chain scissioning effect of irradiation. The Ozawa component n represents a rod shaped, disc shaped and sphere-shaped geometry of the crystal if the value corresponds to 2, 3 and 4, respectively. Based on Ozawa analysis, the values of n were 3.8 and 2.3 for the pure PP and PP blends with 30 wt% LDPE, respectively. The fact that the crystal geometry of PP changed from spherical to disc and rod shaped was confirmed by Ozawa analysis and POM. The β form XRD peak of the PP/LDPE blend at 16.1o disappeared after irradiation due to the crosslinking reaction.

연구 논문 : 우루시올을 활용한 폴리우루시올(PUOH)제조 및 LDPE/PUOH 복합필름 특성에 관한 연구

김도완 ( Do Wan Kim ),김인수 ( In Soo Kim ),서종철 ( Jong Chul Seo ),서정상 ( Jung Sang Seo ) 한국공업화학회 2012 공업화학 Vol.23 No.6

옻나무에서 추출한 우루시올은 우수한 열안정성, 항균성 및 항산화 특성을 가지고 있으나, 알러지를 유발한다고 알려져 있다. 본 연구에서는, 알러지 유발원을 가지고 있는 우루시올을 안전하고 편리하게 사용하기 위하여 폴리우루시올(Polyurushiol, 이하 PUOH) 분말을 제조하였다. 우선, 제조한 분말에 대한 FTIR, SEM, 항산화 및 항균성에 대한 테스트를 실시하였다. Twin screw extruder system을 이용하여 PUOH 분말의 함량 변화에 따른 LDPE/PUOH 복합필름을 제조하였고 액티브 패키징(active packaging) 소재로서의 실현 가능성을 확인하였다. 제조한 LDPE/PUOH 복합필름에 대한 화학적 구조, 모폴로지, 열적특성, 광학적 특성 그리고 항균성 테스트를 PUOH함량 변화에 따라 실시하였다. FTIR과 SEM 결과 PUOH 분말의 함량이 증가할수록 LDPE와 PUOH 분말 사이에 화학적 결합이나 상호작용이 약하며, 분산성 및 혼화성이 좋지 않음을 확인하였다. 열적특성은 PUOH의 함량이 3%까지만 향상시켰다. Pure LDPE와 비교해보면, PUOH의 함량이 증가할수록 LDPE/PUOH 복합필름의 자외선 흡수성과 E. coli에 대한 항균성이 증가하는 것을 확인하였다. LDPE/PUOH 복합필름을 패키징 소재로서 성능을 극대화하기 위해서는 PUOH 분말과 필름의 분산성 향상에 관한 추가적인 연구가 필요하다는 것을 확인하였다. Urushiol extracted from lacquer tree exhibits good thermal stabilities as well as antimicrobial andantioxidant properties. However, it has been known that the urushiol derivates bring out allergy. In this study, polyurushiol (PUOH) powders were successfully synthesized for the safe and convenient handling of allergic urushiol. First, the as-synthesized PUOH was confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), thermal gravimetric analyzer (TGA), antioxidant test and antimicrobial test. And then, six different LDPE/PUOH composite films were prepared via a twin screw extruder system and investigated their feasibility to use as active packaging materials. Their chemical structures, morphology, thermal optical and antimicrobial properties of the LDPE/PUOH composite films were investigated as a function of PUOH contents. FTIR and SEM results showed that LDPE/PUOH composite films have a weak interfacial interaction and poor dispersion with a high PUOH loading. The thermal properties increased up to 3 wt% as the content of PUOH increases. Compared to the pure LDPE films, LDPE/PUOH composite films are more effective in the UV absorbance and antibacterial activity against E. coli. To maximize the performance of LDPE/PUOH compositefilms as the packaging materials, further researches are required to enhance the dispersion of PUOH powders in the LDPE matrix.

3D 프린터 용 PLA/LDPE 고분자 블렌드 모노필라멘트

김유진,최혜미,신동수,김규식,장순호,오태환,Kim, Yu Jin,Choi, Hye Mi,Shin, Dong Soo,Kim, Gyu Sik,Jang, Soon Ho,Oh, Tae Hwan 한국섬유공학회 2018 한국섬유공학회지 Vol.55 No.3

In this study, the effects of a compatibilizer and the blend ratio of low-density polyethylene (LDPE) on the 3D printability of polylactic acid (PLA)/LDPE monofilaments were investigated. Two kinds of PLA and LDPE with different melt indices (MI) were selected for the PLA/LDPE blend monofilaments. An ethylene/butyl acrylate/glycidyl methacrylate terpolymer, having affinities for both PLA and LDPE, was used as a compatibilizer. The tensile strength of the PLA/LDPE monofilaments decreased with increasing amounts of LDPE. PLA with a lower MI of 6 showed better printability than PLA with higher MIs of 15-30, due to its higher viscosity. When the compatibilizer was added, the compatibility and 3D printability increased. The printability increased when the compatibilizer was added up to 20 wt.%, but decreased when LDPE was added at over 30 wt.%.

LDPE-나노 ZnO 복합필름의 기능성 및 재질안정성 평가

이우석,고성혁,Lee, Wooseok,Ko, Seonghyuk 한국포장학회 2018 한국포장학회지 Vol.24 No.1

In this work, nano ZnO was introduced into low density poly ethylene (LDPE) composites films with various contents (0, 0.5, 1.0, 3.0 and 5.0 wt%) by melt-extrusion. Their basic properties such as crystallinity, chemical bonds and surface morphology were examined by XRD, FTIR and SEM. XRD patterns and FTIR peaks intensity were increased in proportion to the ZnO contents. SEM images showed well dispersed nano ZnO in LDPE composite films. Antimicrobial functionality of LDPE-nano ZnO composite films was also studied and the presence of nano ZnO resulted in significant improvement of antimicrobial functionality compared to the pure LDPE film. To evaluate influence of nano ZnO on LDPE properties required as packaging material, thermal, mechanical, gas barrier and optical properties of LDPE-nano ZnO composite films were characterized with various analytical techniques including TGA, UTM, OTR, WVTR and UV-Vis spectroscopy. As a result, except optical and mechanical properties of LDPE, no significant effects were found in other properties. Opacity of pure LDPE was greatly increased with increasing concentration of nano ZnO and tensile strength was also improved at 0.5wt% ZnO content.

LDPE-나노 TiO₂ 복합 필름의 기능성 및 재질안정성 평가

이우석,고성혁,Lee, Wooseok,Ko, Seonghyuk 한국포장학회 2017 한국포장학회지 Vol.23 No.2

In this work, the effects of nano $TiO_2$ on functionality and stability of low density polyethylene (LDPE) composite films were investigated for food packaging application. LDPE-nano $TiO_2$ composite films were prepared with various $TiO_2$ contents (0, 0.5, 1.0, 3.0 and 5.0wt%) by melt-extrusion and their basic properties such as crystallinity, chemical bonds and surface morphology were examined by XRD, FTIR and SEM. Ultraviolet (UV) light barrier property of as-prepared LDPE-nano $TiO_2$ composite films was also studied and the presence of nano $TiO_2$ resulted in significant improvement of UV light barrier compared to the pure LDPE film. To evaluate influence of nano $TiO_2$ on LDPE properties required as packaging material, thermal, mechanical, gas barrier and optical properties of LDPE-nano $TiO_2$ composite films were characterized with various analytical techniques including TGA, UTM, OTR, WVTR and UV-vis spectroscopy. As a result, except optical property of LDPE, no significant effects were found in other properties. Opacity of pure LDPE was greatly increased with increasing concentration of nano $TiO_2$.

A Study of Thermal Properties of LDPE-Nanoclay Composite Films

Nattinee Bumbudsanpharoke,Seonghyuk Ko 한국포장학회 2015 한국포장학회지 Vol.21 No.3

This work focused on the study of thermal properties and kinetic behavior of LDPE- nanoclay composite films. The effect of nanoclay content (0.5, 1, 3, and 5 wt%) on thermal stability and crystallization characteristics of the nanocomposites were investigated by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The results from endothermic curve showed that the nanoclay played an important role in the crystallization of nanocomposites by acting as nucleating agent. From exothermic curve, there was a crystallization temperature shift which was attributed to crystallization process induced by nanoclay. The TGA results showed that the addition of nanoclay significantly increased the thermal stability of LDPE matrix, which was likely due to the characteristic of layered silicates/ clays dispersed in LDPE matrix as well as the formation of multilayered carbonaceous- silicate char. A well-known Coats- Redfern method was used to evaluate the decomposition activation energy of nanocomposite. It was demonstrated that introducing of nanoclay to LDPE matrix escalated the activation energy of nanocomposite decomposition resulting in thermal stability improvement.

LDPE/TPEE 블렌드 필름으로 보강된 아라미드 방검패드의 제조와 방검 성능

이일재,최진현,김지현,백두현 한국섬유공학회 2022 한국섬유공학회지 Vol.59 No.1

Anti-stab pads were prepared by laminating LDPE/TPEE blend films on aramidfabrics to improve the stab resistance. Poly(ethylene-co-glycidyl methacrylate) (EGMA) wasused as a compatibilizer to improve the compatibility of LDPE and TPEE. The properties ofthe LDPE/TPEE blends and anti-stab pads were analyzed according to the blend compositionand compatibilizer content. The surface and cross-section of the LDPE/TPEE blendsand anti-stab pads were observed by scanning electron microscopy (SEM), and thermalproperties were analyzed by differential scanning calorimetry (DSC). The rheological propertiesof the blends were analyzed by the rheometer, and the anti-stab properties wereanalyzed through the quasi-static test using a universal testing machine (UTM). The antistabpads showed best performance when EGMA content was 3 wt%, which was thoughtto be due to the compromise between the melt viscosity increasing effect and themechanical property enhancement effect of the LDPE/TPEE blends.

타포린 코팅층용 저밀도 폴리에틸렌 필름의 자외선 안정성

김윤진,최재호,임정남,Kim, Yoon Jin,Choi, Jae Ho,Im, Jung Nam 한국섬유공학회 2017 한국섬유공학회지 Vol.54 No.3

Tarpaulins are coated fabrics having various industrial applications. Environmental concerns related to the phthalate-plasticizer and limited recyclability of PVC tarpaulins have recently been raised. Although LDPE has been considered a good substitute for PVC, the poor UV stability and low adhesion of LDPE films limit their applications. In this study, various Hindered Amine Light Stabilizers(HALS) were compounded with LDPE. In addition, ethylene vinyl acetate(EVA) was also blended into LDPE in order to improve its adhesion. Although the initial tensile strength and elongation were decreased by the addition of HALS, the UV stability of the films was significantly improved. The adhesion of LDPE was improved by blending with EVA. The LDPE/EVA blended films maintained more than 90% of their tensile strength and elongation compared to their initial values, even after 1,000 hrs of UV irradiation, when the content of EVA were 12 and 18 wt%.

항균성물질이 함유된 세라믹 LDPE필름의 항균효과 및 식품의 저장성

김현수,성림식,유대식 한국생물공학회 2000 KSBB Journal Vol.26 No.4

다양한 식품의 미생물에의한 변패를 억제하고 저장성을 높 일수 있는 포장필름을 개발하기위하여, 미생물이 생산하는 천연 항균성 물질을 홉착시킨 합성 세라믹올 첨가하여 세라 믹 LDPE 필륨을 제조하였다. 천연 항균제로는 methanol자화 방선균 MO-16 및 MO-17균이 생산한 항세균제와 새로이 분 리한 방선균 No. 31이 생산한 항진균제를 사용하였다. 방선 균 No. 31이 생산한 항진균성 불질은 배양 4일째 항균효과가 우수하였으며, $121^{\circ}C$에서 15분간 열처리시에도 항균력이 유 지되는 내열성이 확인되었다. 제조한 세라믹 LDPE 필름의 미생불 생육 억제효과를 검토한 결과 조분쇄한 돈육의 경우 포장하여 실온 및 $4^{\circ}C$에서 보존시 시판필름에 비해 미생물 생육 억제효과가 우수하였다. 고제배지에 제조필름을 첨가하 여 E. coli에 대한 항균효과를 검토한 결과 첨가량에 따라 항 균효과가 우수한 것이 입증되었다 제조펼름으로 포장한 6종 류의 식품에 대한 저장성을 검토한 결과 시판필름에 비해 저 장성이 우수한 것이 확인되었으며 특히 양송이에 대한 저장 효과가 우수하였다. Low density polyethylene(LDPE) film was fabricated with the addition of synthetic ceramic which contained a natural antimicrobial agents. The antimicrobial agents used were isolated from culture broths of methylotropic actinomycetes strains MO-16 and MO-17, and Streptomyces sp. No. 31, which was newly isolated from soils as an antifungal agent. Four-day old culture broth of Streptomyces sp. No. 31 showed strong antifungal activity against Aspergilus niger, a test strain, and retained antimicrobial activity after heat treatment at $121^{\circ}C$ for 15 min. The ceramic LDPE film reduced the growth of total aerobic bacteria in packaged minced pork compared with commercial film. The film revealed a 40 to 50% growth inhibition of E. coli on a contained agar plate. In the storage testing of various packaged foods at room temperature for 30 days, the ceramic LDPE film showed excellent preservation compared with commercial film.