• 대한약침학회지
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• 제25권4호
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• pp.317-325
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• 2022

Polymers are the major constructive material of pharmaceutical formulations that play a prime role in designing effective drug-delivery systems and releasing drugs at their sites of application. Polymers are composed of multiple repeating units of high molecular mass components with attendant properties. Most synthetic polymers are non-biocompatible, expensive, and extremely inclined to deliver adverse impacts. Meanwhile, edible polymers obtained from natural sources have gained remarkable recognition for their promising use in modern medicine. Moreover, polymers derived from natural sources are generally preferred due to certain of their unique features such as abundant availability, biocompatibility, nontoxicity, economical, safe, and effective functions that fit the purpose. Polysaccharides including starch, cellulose, hemicellulose, pectin, and mucilage are identified as a major class of naturally obtained molecules that have a substantial role as functional polymers. This review summarizes the potential role of polysaccharides derived from vegetable sources such as adhesives, anticaking agents, binders, disintegrants, emulsifiers, film-framing agents, and thickeners. This is simply an opportunity to abandon synthetic excipients that hurt our bodies and think back to nature from where we originate.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.216-216
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• 2006

A special group of polymers, those from renewable resources, has attracted an increasing amount of attention over the last two decades, due to two major reasons: environmental concerns and the limitations of our finite petroleum resources. Generally, polymers from renewable resources (PFRR) can be classified into three groups: (1) natural polymers, such as starch, protein and cellulose; (2) synthetic polymers from natural monomers, such as polylactic acid (PLA); and (3) polymers from microbial fermentation, such as polyhydroxybutyrate (PHB). Like many other petroleum based polymers, various properties of PFRR are also vastly improved through blending and composites formation.

• 자연과학논문집
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• 제5권1호
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• pp.59-65
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• 1992

아실옥시이미노(AOI)기를 갖는 포리마의 광반응 특성을 검토한 결과, 포리마 주쇄의 구조에 따라 주반응이 다른것을 알았다. 아크릴타입(AAPO)포리마에서는 아미노기의 생성이 주 반응임에 반해 메타크릴타입(MAAPO)포리마에서는 주쇄절단반응과 이중결합 생성반응이 주 반응임을 알았다. 또한 본 연구에서는 광반응의 메카니즘을 정량분석을 통해 철저히 규명함과 아울러 이들 주 반응에서 생성된 아미노기와 주쇄절단반응을 이용한 기능성고분자에의 응용에 대해서도 연구 검토하였다.

• Macromolecular Research
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• 제8권5호
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• pp.199-208
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• 2000

The recent development of biodegradable polymers for drug delivery system (DDS) has been investigated. The biodegradable polymers for DDS are mainly discussed in two categories: one category is natural biodegradable polymers such as polysaccharides, modified celluloses, poly(${\alpha}$-amino acid)s, modified proteins, and microbial biodegradable polymers; the other is synthetic biodegradable polymers such as poly(ester)s, poly(ortho ester)s, poly(phosphazene)s, poly(anhydride)s, poly(alkyl cyanoacrylate)s, and multiblock copolymers. The bioconjugate polymeric drug delivery systems have been also proposed for the design of biocompatible polymeric controlled drug delivery.

• Bulletin of the Korean Chemical Society
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• 제33권6호
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• pp.2017-2022
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• 2012

Three isostructural lanthanide coordination polymers, $[Ln(L)_3(H_2O)_2](H_2O)_3$ {Ln = Eu (1), Tb (2), Gd (3); L = $trans$-3-(3-pyridyl)acrylate, (3-py)-CH=CH-COO}, were prepared from HL, lanthanide nitrate, and NaOH in $H_2O$ by microwave heating. In all coordination polymers, the metal is bonded to eight oxygen atoms, and all pyridyl nitrogen atoms do not coordinate to the metals. All polymers have a 1-D loop-connected chain structure. The hydrogen atoms in the aqua ligands and lattice water molecules all participate in the hydrogen bonds of the O-$H{\cdots}O$ or O-$H{\cdots}N$ type. The hydrogen bonds connect the 1-D chains to create a 2-D network. Polymer 1 exhibited red luminescence in the solid state at room temperature.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1649-1654
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• 2003

We have investigated substituent effect on the stabilization energies, and nucleus-independent chemical shifts of pentafulvalenes and on the electronic structures of the corresponding polypentafulvalenes to design environmentally stable semiconductive or conductive polymers. Geometrical optimizations of the molecules were carried out at the density functional level of theory with B3LYP hybrid functional and 6-311+G(d) basis set. Stabilization energies were estimated using isodesmic and homodesmotic reactions. As a criterion of aromaticity nucleus-independent chemical shifts of the molecules were computed using GIAO approach. For the polymers the geometrical parameters were optimized through AM1 band calculations and the electronic structures were obtained through modified extended Huckel band calculations. It is found that strong electronwithdrawing substituents increase isodesmic and homodesmotic stabilization energies of pentafulvalene, though it does not increase the aromaticity. Nitro-substituted pentafulvalene is estimated to have stabilization energy as much as azulene. However, substitution either with electron-donating groups or with electronwithdrawing groups does not significantly affect the electronic structures of polypentafulvalene and poly (vinylenedioxypentafulvalene).

• Korean Chemical Engineering Research
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• 제43권1호
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• pp.176-180
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• 2005

방향족 Schiff base 메소제닉 단위와 폴리메틸렌 유연격자로 이루어진 한 계열의 주사슬 액정중합체와 네 계열 화합물의 액정성을 살펴보았다. 이들의 열적 성질과 액정성은 시차 주사 열분석기와 가열판이 부착된 편광현미경에 의하여 조사하였다. 중합체와 화합물 액정상의 성질은 중앙 폴리메틸렌 유연격자와 말단 알콕시기의 길이에 크게 의존하였다. 중합체 I과 계열 III 화합물은 녹는점과 등방성액체화 전이온도에서 짝수-홀수 효과를 보여 주었으나 계열 II와 IV 화합물은 등방성액체화 전이온도에서만 짝수-홀수 효과를 나타내었다. 편광현미경을 통하여 이들의 광학구조를 관찰하였을 때 네마틱과 스멕틱 액정상을 형성하였다.

• 자연과학논문집
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• 제9권1호
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• pp.89-93
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• 1997

여러 가지의 친수성기와 소수성기를 함유하는 폴리포스파진을 합성하고 이들 고분자의 가교 반응을 수행하였다. 사용한 치환기는 (2-메톡시에톡시)에톡시기와 2,2,2-트라이플로로에톡시, 페닐옥시, 알라닌 등이었다. 합성된 고분자의 가교는 감마선 조사, 자외선 조사 및 가교제와 감광제를 사용한 자외선 조사 등의 방법을 사용하여 가교시켰다. 세가지 방법 중에서 가교제와 감광제를 사용한 자외선 조사가 가장 좋은 결과를 주었다. 얻어진 고분자를 물에 담궈 하이드로젤을 얻어내었으며 이들의 성질을 간략히 조사한 결과 모든 경우 최저 임계온도를 나타내는 행동을 하였다.

• Bulletin of the Korean Chemical Society
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• 제21권3호
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• pp.321-327
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• 2000

Polynucleotide analogues containing pyrimidine (uracil and thynime) bases, $poly[(1'{\beta}-uracil-1-yl-2'.5'-dideoxy-D-glycero-pent-4'-enofuranose)-alt-(maleic$ acid)] (12) and $poly[(1'-{\beta}-thymin-1-yl-2'5'-dideoxy-D-glycero-pent-4'-enofuranose)-alt-(maleic$, acid)] (15), were synthesized by the altermating copolymerization of relevant nucleosied derivatives and maleic anhydride, and the subsequent hydrolysis. The polymers had quite similar structures to the natural polymes and were soluble in water, They showed high hypochromicities up to 49% and excimer fluorescence due to the base stacking, and polyelectrolyte behavior. Since the polymers had compact structrures, depyrimidinations, the release of pyrimidine bases from the polymer backbone, occurred in aqueous solutions with higher rates compared with those of the natural polymers.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.464-468
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• 1999

The effectiveness of current biodegradation test methods for degradable polymers under controlled composting conditions was studied in regards to the test temperature and compost condition. When biodegradability tests for the natural (starch, cellulose, PHB/HV) and synthetic (PCL, SG, PLA) polymers were conducted at temperature levels of 35 and $55^{\circ}C$ with compost cured at ambient temperature, the degradations of cellulose and starch were higher at $35^{\circ}C$ because of the priming effect. On the other hand, degradations of other polymers were higher at $55^{\circ}C$. In the biodegradation test at $55^{\circ}C$, compost harvested right after the thermophilic degradation stage showed higher biodegradation activities than the cured compost for both the synthetic aliphatic polyester (SG) and a natural polymer, cellulose. These results suggest that the biodegradation test conducted at $55^{\circ}C$ with the compost, harvested right after the thermophilic degradation stage during composting, showed the highest biodegradation activity under controlled composting conditions.