Abstract
本研究旨在探討酚醛樹脂和不同的樹脂(苯氧樹脂, 聚丁二酸酯族及聚氧化乙烯)聚摻合物的相容性, 熱力學性質及分子的運動性. 由微分示差掃描儀, 固態核磁共振儀及Painter-Coleman結合模型等方法來探討. 由於苯氧樹脂, 聚丁二酸酯族及聚氧化乙烯等熱塑性樹脂均包含有氫鍵官能基, 會和酚醛樹脂產生分子間氫鍵, 所以這一些酚醛樹脂的聚摻合物均是相容, 其分子間氫鍵強度依序是酚醛樹脂/苯氧樹脂, 酚醛樹脂/聚丁二酸酯族, 最後為酚醛樹脂/聚氧化乙烯聚摻合物. 換言之, 氫鍵強度依序是羥基-羥基, 羰基-羥基, 而醚基-羥基之間的氫鍵強度最低. 由PCAM可以預測所有的酚醛樹脂聚摻合物的混合自由能均呈負值. 在高溫之下, 聚摻合物中的倫敦分散力(London dispersion force)將取代分子間氫鍵, 所以酚醛樹脂的聚摻合物會發生相分離的現象, 而焓的因素造成相分離的比重大於熵的因素. 如果不考慮聚摻合物的熱裂解溫度時相分離的溫度依序為聚氧化乙烯, 聚丁二酸醋族, 而苯氧樹脂最低. 因為酚醛樹脂/聚氧化乙烯聚摻合物的平均氫鍵強度最強, 須要在較高溫度時, 倫敦分散力才能取代氫鍵作用力. 酚醛樹脂聚摻合物的玻璃轉移溫度取決於改質高分子的結構, 改質高分子的結構會影響聚摻合物的平均氫鍵強度, 而直接影響聚摻合物的玻璃轉移溫度. 酚醛樹脂聚摻合物的平均氫鍵強度呈現正偏差, 如同酚醛樹脂/聚氧化乙烯聚摻合物. 相反的, 如果酚醛樹脂的聚摻合物的平均氫鍵強度減少時, 玻璃轉移溫度將呈現負偏差, 如同酚醛樹脂/苯氧樹脂, 酚醛樹脂/聚丁二酸酯族聚摻合物. 這一些改質高分子與酚醛樹脂聚摻合時, 會阻礙酚醛樹脂的自身氫鍵交互作用, 而建立新的分子間氫鍵. 如果新的分子間氫鍵可以彌補失去的酚醛樹脂的自身氫鍵, 結果玻璃轉移溫度呈現正偏差. 利用固態核磁共振的技術研究酚醛樹脂聚摻合物的分子運動性. 研究結果顯示分子運動性除了受自由體積的影響外,亦受改質高分子的性質影響. 當酚醛樹脂與苯氧樹脂聚摻合時, 其聚摻合物的剩餘體積呈正值, 酚醛樹脂的分子運動性將會增加. 當酚醛樹脂與聚氧化乙烯聚摻合時, 其聚摻合物的剩餘體積呈負值, 酚醛樹脂的分子運動性也將增加, 因為酚醛樹脂的交互作用的對象是柔軟的熱塑性樹脂. 這些酚醛樹脂的分子運動性均在固態核磁共振的技術中( 如化學位移, T1r 弛緩時間, T1弛緩時間分佈, 及交錯極化效率Tch)有完整的描述,當分子運動性增加時, T1弛媛時間, 交錯極化效率及T1r弛緩時間減少; 反之, 則增加. 酚醛樹脂加入結晶性的熱塑性樹脂, 如聚氧化烯, 聚丁二酸酯族時, 結晶性的熱塑性樹脂的結晶形態將會被破壞, 隨著酚醛樹脂量的增加可以使結晶完全破壞. 而結晶破壞的程度取決於熱塑性樹脂的結晶潛能及分子間氫鍵的強度. 本研究發現, 聚氧化乙烯的結晶潛能最高, 而單一分子間氫鍵強度最低, 所以須要以最多量的酚醛樹脂來破壞氧化乙烯的結晶, 其為它依序為聚丁二酸癸酯, 聚丁二酸辛酯, 最低為聚丁二酸已酸酯.The miscibility, and molecular interaction within novolactype phenolic resin blended various thermoplastic resin(i.e.phenoxy, poly adipic ester, and poly ethylene oxide)wereinvestigated. Differential scanning calorimetry (DSC), solidstate magnetic nuclear resonance (NMR)and Painter-ColemanAssociation Model(PCAM) were used to study the miscibility,thermodynamic properties and the molecular motion of phenolicblends. All the thermoplastic resin are miscible with novolactype phenolic resin, due to strong intermolecular hydrogenbonding present in the phenolic blend. The Gibbs freefreeenergies of various phenolic blends are negative through thewhole blend compositionsthat simulated from the PCAM model. Theorder of intermolecular hydrogen bonding strengthis phenolic/phenoxy, phenolic/poly adipic ester, and then phenolic/PEOblend. In other word,the hydrogen bonding strength of hydroxyl-hydroxyl is the strongth, carbonyl-carbonyl is the second, anthe ether-hydroxyl is the weakest on in this blend system. Thephase separationn would occur when the London dispersin forcedominates over the hydrogen bondingat higher temperature inphenolic blends. The order of phase separation temperature isPEO,poly adipic ester, and then phenoxy while the degradatintemperature is not consideredin this blend system. The enthalpicterm causes the phase separation is weightout thanthe entropicterm at higher temperature for phenolic blend. The glasstransition temperature of phenolic blend was dependent on themodifierstructure, as well as the average strength of hydrogenbonding of polymer blend. In the phenolic/PEO blend, the averagestrength of hydrogen bonding of phenolic blend increasedthatresults in the positive derivation of glass transitiontemperature. On the contrary,in the phenolic/phenoxy andphenolic/poly adipic ester blend system, the descreasingofaverage of hydrogen bonding leads to the negative derivationof glass transition temperature. The miscible modifier wouldhinder the self-association of phenolic, and forms theintermolecular hydrogen bonding. When the intermolecularhydrogen bondingcan compensate the loss of self-association ofphenolic, that resulting in a positivederivation of glasstransition temperature. The solid state NMR is used to studythe molecular motion and miscibility of phenolicblend, which isdependent on the free volume of phenolic blend. In the phenolic/phenoxyblend, the excess free volume of polymer blend ispositive. In the phenolic/PEO, due to the phenolic interactswith flexible thermoplastic chain, the molecular motionofphenolic is still increased when the excess free volune isnegative. The solid stateNMR (i.e. chemical shift, T1r timerelaxation. T1 relaxation time dispersion, and efficiency ofcross polarization) can interpret all of the molecular motion ofphenolic blend. When phenolic was added to the thermoplasticresin the crystallinity of PEO and poly adipic ester will bedecreased, and the crystalline would be destroyed completely.Thedegree of the decreasing of crystalline is dependent on thecrystallizatin polentialof thermoplastic reisn and also on thestrength of intermolecular hydrogen bonding. ThePEO exhibits thehighest crystallization and the lowest intermolecular hydrogenbondingwith phenolic, it need the most amount of phenolic todestroy the crystalline of PEO in the blend s