ポリビニルピロリドンのモラ質量と濃度の食品包装用ポリミルク酸の物理機械的特性への影響
Contact us if these videos are not relevant.
Contact us if these videos are not relevant.
PubMedで要約を見る
まとめ
この要約は機械生成です。ポリミルク酸 (PLA) フィルムにポリビニルピロリドン (PVP) を加えると,生物分解性が向上する. 低分子量PVP (PVP10) は5〜10%で,食品包装の用途に最適のバランスをとります.
科学分野
- ポリマー科学
- 材料科学
- 持続可能な包装
背景
- ポリ乳酸 (PLA) は生物分解性ポリマーで,食品の包装に利用できる可能性がある.
- 生物分解性や溶解性を含むPLAの寿命終了後の性能を改善することは極めて重要です.
- 水性改良剤は,PLAの水吸収と分解率を高めることができます.
研究 の 目的
- ポリビニルピロリドン (PVP) がPLAフィルムに与える影響を調査する.
- 異なるPVPモラー質量 (PVP10とPVP40) がPLAの構造,熱,機械,光学,バリア特性に影響を与えるかを評価する.
- 生物分解性と包装性能の向上のために最適なPVP濃度を決定する.
主な方法
- 2つの異なる分子量PVP (PVP10,PVP40) の濃度が異なるPLAフィルムを溶かして挤出する.
- 熱分析 (DSC),スキャニング電子顕微鏡 (SEM),弱体化された総反射率フーリエ変換赤外線スペクトロスコピー (ATR-FTIR),機械的試験 (張力強度,硬度) および光学特性測定を用いた特徴付け.
- 水の吸収と分解の評価
主要な成果
- PVPの含有により,ガラスの移行温度がわずかに低下し,特にPVP10では,鎖の移動性が増加した.
- PVPを添加すると2段階の分解プロセスが観察されました.
- PVP10は5~10%の重量で良好な分散を示し,機械的整合性を保ち,PVP40は相分離と脆化をもたらした.
- 光学特性は変化し,不透明性と色差が増加し,光に敏感な製品には潜在的に有益です.
結論
- 低分子量PVP (PVP10) を5~10%で改造したPLAフィルムは,水に強い親和感を示し,包装に関連する性質の好ましいバランスをとる.
- PVP10は,食品包装におけるPLAの生物分解性と使用終了性能を改善するための有望な添加物です.
- 高分子量PVP (PVP40) は有害な相分離と機械的弱体化をもたらす.
関連する概念動画
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
For any given polymer, the weight average molecular weight (Mw) is higher than, if not equal to, the number average molecular weight (Mn). The only situation in which the weight average molecular weight and the number average molecular weight are equal is when a polymer consists only of chains with equal molecular weight. However, this never happens in a synthetic polymer, since it is difficult to control the polymerization process up to a molecular level with accuracy to a hundred percent.
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
Unlike small molecules with definite molecular weights, polymers are a mixture of individual polymer chains of varying lengths, each with a unique molecular weight. So, the molecular weight of a polymer is expressed as an average value based on the average size of the polymer chains. The two most common forms of averages used for polymers are the number average molecular weight and weight average molecular weight.
The number average molecular weight (Mn) is the summation of the number...
Carboxylic acids with lower molecular weight exhibit a sharp and unpleasant odor. They also have higher boiling and melting points than analogous compounds, such as aldehydes, ketones, and alcohols.
In addition to the dipole–dipole interaction of the polar carbonyl and hydroxyl bonds, strong intermolecular hydrogen bonding between carboxylic acid molecules dictates several physical properties.
The strong interaction causes the carboxylic acid molecules to exist in stable dimers,...