저자는 과학 연구를위한 네덜란드 기구 (NWO)의 재정 지원에 감사드립니다 (보조금 023.007.020 잭 반 Schijndel에 수여).

1. 5 mol% 중탄산염을 가진 시리갈데히드의 녹색 Knoevenagel 응축
<ol><li>250mL 라운드 하단 플라스크에 실로산(20.81g, 200.0 mmol)과 주사기알데히드(36.4g, 200.0 mmol)를 추가합니다. 에틸 아세테이트 20.0 mL에 두 성분을 녹이고 플라스크에 암모늄 중탄산염(790 mg, 10.0 mmol)을 추가한다. 참고: 응축 반응의 완전한 완성을 보장하기 위해, 회전 증발기를 사용하여 에틸 아세테이트를 증류하고 반응 혼합물을 농축하여 용매가 없는 반응을 초래할 수 있다.</li>
	<li>시나피닉산으로 완전한 변환을 위해 교반하지 않고 열린 플라스크에서 90°C에서 2시간 동안 반응 혼합물을 보관하십시오. 참고: 이 반응 중에 몇 가지 형태학적 변화가 관찰됩니다. 반응 혼합물은 응축 단계 동안 물의 형성으로 인해 조밀한 회색 혼합물에서 용해된 노란색 혼합물로 변경됩니다. 응축수의 증발 후, 반응 혼합물은 다시 고화되어 전체 변환을 나타냅니다.</li>
	<li>시나피닉산 생성물의 작용에서, 포화 수성 NaHCO 3-용액의 100mL에서 잔류물을 용해한다. 용액을 비커로 옮기고 6M HCl을 사용하여 2의 pH로 산성화한다. 참고: 포화 수성 NaHCO3-솔루션을추가하는 동안 원유 제품은 천천히 용해되고 완전히 용해되기 위해 약간의 시간과 수동 스크래핑이 필요합니다. 일단 완전히 용해되고 비커로 옮겨지면 6 M HCl의 산성 용액이 드롭 와이즈를 추가합니다. 시나피닉 산은 빠르게 침전되고 CO2 가스가 방출되면 제품이 거품이 됩니다.</li>
	<li>생성된 잔류물을 진공 여과로 분리하고 탈염된 물로 세척합니다. 참고: 이 시점에서 제품의 순도는 HPLC에 의해 분석될 수 있습니다. 제품이 오염된 것처럼 보이는 경우 다음 정화 단계(예: 재결정화)를 적용해야 합니다.</li>
	<li>물에 탄올 (4:1, v/v)의 혼합물로 재구성 한 후 진공 여과로 결정을 분리하십시오. 진공 오븐에서 60°C에서 잔류물을 건조시켜 42.56g의 순수 시나피닉 산을 생성합니다. 참고: 시나피닉산의 순도는 융점 분석 및 HPLC에 의해 측정됩니다.</li>
</ol>2. 라니TM 니켈을 가진 디하이드로시나피닉 산을 향한 시나피닉 산의 수소화.
<ol><li>시나피닉산(33.6g, 150mmol)으로 450mL 플라스크(수소화 장치 사용)를 충전합니다. 2M NaOH 용액의 300mL에 시나피닉 산을 녹이고 장치에 플라스크를 장착하기 전에 니켈 슬러리 1.5g(재료 표참조)을 추가합니다. 참고 : 알칼리성 용액의 첨가로 인해 반응 혼합물의 색상이 변경됩니다. 시나피닉 산은 결정적인 형태로 노란색이 되지만, 기지에 의해 분해되면 용액의 색상이 빨간색으로 변경됩니다. 니켈의 첨가는 검은 색을 켭니다.</li>
	<li>3개의 바의 수소 가스로 반응기를 가압하고 3시간 동안 80°C에서 기계적으로 반응을 흔들어 줍니다.</li>
	<li>원자로를 실온으로 식히고 천천히 우울하게 합니다. 대부분의 니켈 촉매를 자석으로 회수한 다음 저압하에서 용액을 필터링합니다. 참고: 반응 혼합물은 여과 후에 보이는 빨간색에서 녹색으로 변경되어야 합니다. 주목할만한 색상 변화는 이중 결합의 수소화에 의해 컨쥬게이트 시스템이 중단되어 있기 때문입니다.</li>
	<li>4M HCl 용액으로 2의 pH를 향해 용액을 산성화합니다. 이어서, 에틸 아세테이트(4배 50mL)로 추출을 수행한다. MgSO4를통해 건조 한 후 감소 된 압력하에서 용매를 제거합니다. 진공 오븐에서 고체 제품 디하이드로시나피닉 산을 60°C에서 건조시십시오. 참고: 이론적으로 다결도 반응은 디하이드로시나피닉 산에서 처리될 수 있지만 몇 가지 실질적인 단점이 있습니다. 분자 구조로 인해, 디하이드로시나피닉산은 융점 위에 승화한다. 승화를 방지하고 반응성을 높이기 위해 아세틸화 반응을 수행할 수 있습니다.</li>
</ol>3. 아세틸화 단량체와 올리고머 (사전 중합체)를 향해 디하이드로시나피닉 산의 아세틸화.
<ol><li>디하이드로시나피닉산(22.6g, 100mmol)을 250mL 라운드 하부 플라스크에 넣고 아세트 안수(14.2mL, 150mmol) 및 아세테이트 나트륨(0.82g, 10mmol)을 넣습니다. 참고: 디하이드로시나피닉 산은 실온에서 아세트 성 수화물에 완전히 녹지 않습니다.</li>
	<li>용액을 90°C로 가열하여 디하이드로시나피닉 산을 4-아세톡시 디하이드로시나피닉 산과 아세틸화 올리고머로 완전히 변환하기 위해 1시간 동안 저어줍니다. 참고 : 모든 제품은 아세트 무수화물에 용해 되어 있습니다. 4-아세톡시 디하이드로시나피닉산의 총 강수량을 증가시키기 위해 다음 단계에서 소량의 수용성 용매를 첨가한다.</li>
	<li>고체를 25mL의 아세톤으로 녹이고 침전물(용매-비 용매)을 0.1 M HCl의 250mL로 끌어들이고 진공 상태에서 적극적으로 교반하고 필터를 한다. 참고: 최상의 결과는 완전히 침전된 흰색의 끈적끈적한 솔리드를 보여줍니다. 제품 용액이 HCl 용액에 너무 빨리 추가되면 제품은 산성 용액의 하단에 갈색 액체로 유지됩니다. 이러한 상황에서, 에틸 아세테이트(4배 50mL)로 전체 제품 용액을 추출한다. MgSO4를통해 건조 한 후, 감소 된 압력하에서 에틸 아세테이트를 제거하십시오. 이 제품은 4-아세톡시 디하이드로시나피닉 산 및 프리폴리머입니다.</li>
</ol>4. 아세틸화 단량체와 올리고머의 중합.
<ol><li>모노머, 4-아세톡시 디하이드로시나피닉산(20.8g, 100mmol)을 넣고 100mL 라운드 하단 플라스크에 사전 폴리머를 넣고 미세하게 가루된 NaOH(400 mg, 10.0 mmol)를 추가합니다. 100 rpm에서 교반하는 동안 열린 플라스크에서 140 °C의 설정 온도에서 반응 혼합물을 3 시간 동안 가열합니다. 참고 : 이 반응 동안, 물과 아세트산은 열린 플라스크에서 응축. 증기의 pH는 아세트산의 응축을 확인하기 위해 측정될 수 있다. 반응 제품의 형태는 용융 상태에서 컴팩트한 밝은 갈색 제품으로 변경됩니다. 설정은 응축수의 증발을 촉진하고 산화를 방지하기 위해 질소 흐름을 실시한다. 이러한 반응은 일반적으로 혼합물의 높은 점도로 인해 기계적 교반기로 교반됩니다. 그러나 자기 교반기의 사용은 충분하며 이 스케일에서는 차이가 무시할 수 있습니다.</li>
	<li>아연(II)아세테이트(180 mg, 1mmol) 및 플라스크에 1,2자일렌의 25.0mL을 추가하여 용매 보조 중합화를 설정한다. 세트 온도를 160°C로 올립니다. 참고: 1,2자일렌의 역류와 중합의 완전한 반응성을 보장하기 위해 세트 온도를 160°C로 올립니다. 반응 자체의 온도는 1,2자일렌의 비등점으로 인해 144°C로 유지됩니다.</li>
	<li>딘 스타크 헤드를 사용하여 일정한 물과 아세트산 제거로 3시간 동안 144°C에서 혼합물을 역류합니다. 참고: 1,2-자일렌을 추가하고 반응 플라스크를 필요한 온도로 가열한 후 시약은 점도가 낮은 갈색 슬러리를 형성합니다. 이러한 낮은 점도는 중합체의 최종 그룹의 이동성에 도움이 되는 것으로 추정되며, 반응성을 촉진한다.</li>
	<li>반응 혼합물을 식히고 진공(<10mbar)을 적용하여 1,2자일렌을 제거합니다. 참고: 반응 혼합물은 용매를 증발시키면서 고화되어 오프 화이트 고체로 변합니다.</li>
	<li>중합의 최종 단계에서 온도를 240°C로 올리고 30분 동안 고진공 <1mbar를 적용한다. 참고: 이 단계에서 는 중합단계에서 사슬 길이를 실질적으로 높이기 위해 소량의 응축만 필요하기 때문에 이 단계에서 는 약간의 응축만이 증발합니다.</li>
	<li>폴리머 폴리-S를 실온으로 냉각하고 메탄올로 세척하여 4-아세톡시 디하이드로시나피닉산 및 사전 중합체를 제거합니다. 얻어진 제품은 밝은 갈색 고체입니다. 참고: 공정 후 폴리에스테르의 체인 길이 및 열 특성은 GPC 및 DSC에 의해 조사됩니다.</li>
</ol>5. 1 M NaOH에서 폴리-S의 중합을 위한 대표적인 절차:
<ol><li>다중-S를 180 μm 보다 작은 입자로 미세하게 갈아서 체로 체로 하여 가수분해성 분해를 측정합니다. 참고: 입자를 필요한 크기로 연마하려면 박격포를 사용하고 액체 질소 냉각 폴리-S로 유봉한 다음 기계적 체질 단계를 수행합니다.</li>
	<li>폴리-S 20 mg의 여러 테스트 튜브를 로드하고 1 M NaOH 솔루션의 1.0 mL을 추가합니다. 제어된 환경 인큐베이터 셰이커를 사용하여 500rpm의 교반과 함께 3개의 다른 온도(RT, 50 및 80°C)에서 튜브를 배양합니다. 참고: 이 반응에 여러 항목이 있는 가열 블록/셰이커를 사용하여 모든 반응이 정확히 동일한(열) 조건에서 이루어지도록 합니다.</li>
	<li>0.5 M H2SO4의 1.0mL로 정규 시간 간격으로 테스트 튜브를 중화하고 냉각 후 메탄올 2.0mL을 추가합니다. 참고: 소량의 폴리-S와 1M NaOH의 1.0mL만이 사용되며, 이러한 농도는 메탄올을 첨가한 후 HPLC에 직접 주입될 수 있으며 더 이상 희석을 필요로 하지 않기 때문에 사용된다.</li>
	<li>자동 샘플러를 사용하여 0.45 μm PTFE 주사기 필터를 사용하여 모든 샘플을 필터링하고 HPLC에 주입 (20 μL). λ = 254 nm에서 흡광도를 모니터링하고 알려진 디하이드로시나피닉 산 표준 솔루션의 교정 곡선으로부터 농도를 계산합니다. 참고: 교정 곡선의 표준 용액은 중합 후 의 작업업과 동일한 용매 혼합물로 이루어져야 합니다.</li>
</ol>

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디하이드로시나피닉산이 반응용기에서 가열되었을 때, 시동물질의 승화가 발생했으며, 진공이 적용되었을 때 이러한 효과가 향상되었다. 아세틸화는 승화를 피하기 위해 디하이드로시나피닉 산에서 수행되었습니다. 크리첼도르프 외12,27은 아세틸화뿐만 아니라 유사하게 디고머화가 발생했다는 것을 인식했다. 그러나, 이러한 에스테르화된 단량체와 ...

중합체 폐기물의 소각과는 달리 화학 적 재활용은 단량체를 회수 할 수있는 가능성을 제공합니다. 화학적 재활용은 이러한 중합체 물질이 화학적으로1을생산되기 때문에 중합체 물질의 기술적 수명이 끝날 때 논리적인 선택이다. 중합체 물질을 화학적으로 재활용하는 방법에는 두 가지가 있다, 용해 및 분자 재활용2. 열분해를 통해 중합체 물질은 극한 조건3,4를사용하여 더 높은 가치의 제품으로 변형된다. 분자 재활용은 중합화를 사용하여 시작 물질을 회수하는 효율적인 방법입니다. 중합 후, 단황 단위는 처녀 중합물질로 재중화될 수있다 5. 더 큰 규모로 분자 재활용을 적용하는 적절한 단량제의 가용성이 원하고 있습니다. 현재의 플라스틱 문제는 사회가 튼튼하고 견고한 중합체 물질을 요구한다고 규정하고 있습니다. 동시에, 동일한 중합체 물질이 쉽게 재활용가능하고 환경에서 견디지 못하는 것이 바람직하다. 현재 열 및 기계적 특성이 좋은 현재 중합재료는 쉽게 폴리머화하지 않는다6.
혈관 식물에서 흔히 발견되는 Lignin은 세계 천연 탄소 함량의 30%를 담당하며 셀룰로오스 다음으로 두 번째로 풍부한 바이오 폴리머입니다. Lignin은 복잡한 비정질 구조를 가지고 있으며 화석 물질에서 추출한 방향족을 대체하기에 적합한 대안으로 보입니다. 리그닌의 입체 구조는 나무에 강도와 강성뿐만 아니라 저하에 대한 저항을 제공합니다. 화학적으로 말하자면, 리그닌은 매우 복잡한 폴리페놀 열집합입니다. 그것은 세 가지 다른 메톡시 페닐 프로판 구조의 다양한 구성으로 구성되어 있습니다. 시링일, 구아실 및 p-하이드록시페닐(종종 S, G, H로 약식)은 모노리그놀 시나필 알코올, 침엽수 알코올 및 p-쿠메릴 알코올7에서유래된다. 이러한 단위의 분포는 바이오매스 유형마다 다르며, 예를 들어, 대부분 과아실 단위와 과아실 및 실링일 유닛8,9의나무로 구성된 과아실 단위로 구성된다. 나무나 식물과 같은 재생 가능한 천연 공급원은 혁신적인 폴리머소재(10)를위해 재설계된 단량체의 생산에 바람직하다. 천연 공급원으로부터 분리되고 합성된 이들 모노머는 소위 바이오기반폴리머(11)로중합된다.
방향족 카복실산은전자상의이유로 동등한 알리팔성 카복실산보다 여러 주 의 크기가 적다. 다양한 상업용 폴리에스테르는 알리팔성 카복실산 대신 방향족 카복실산을 사용합니다. 그 결과, 폴리에스테르섬유(에틸렌 테레프탈레이트)(PET) 섬유로 만든 섬유는 세척 중 가수 분해에 거의 민감하지 않거나, 예를 들어,비(13)에민감하다. 폴리에스테르의 분자 재활용이 원할 때, 폴리머의 축적에 알리파성 에스테르를 사용하는 것이 좋습니다.
언급 된 이유로, 우리는 4 하이드록시 -3,5-디하이드로신산14에서폴리 에스테르를 만드는 가능성을 조사했다. Kricheldorf15,마이어16및 밀러17,18에 의한 이전 연구는 4-하이드록시-3,5-디메톡시 디하이드로신산을 사용하여 폴리머를 구축하는 것이 어렵다는 것을 보여줍니다. 탈카복틸화와 교차 연결은 중합을 방해하고, 그래서 이러한 합성의 성공을 제한. 또한 다결도의 메커니즘은 불분명했습니다. 제시된 논문은 폴리에스테르 폴리(dihydrosinapinic acid)가 정기적으로 고수율로 합성될 수 있는 조건을 설명하므로 분자재활용가능한 반 방향족 폴리에스테르를 사용하는 길을 열어줍니다.
우리는 주사기알데히드와 말론산19,20사이의 응축 반응을 사용하여 시나피닉 산을 합성하는 녹색이고 효율적인 방법을 개발했습니다. 이 녹색 Knoevenagel 후, 수소화는 가역 다결관화에 적합한 디하이드로시나피닉 산을 생성합니다. 이 간행물은 폴리-S라고 불리는 리그닌의 기체를 지칭하는 분자 재활용 가능한 폴리머 폴리(dihydrosinapinicacid)에 합성 단계를 시각화합니다. 중합체 물질을 분석한 후, 폴리-S는 비교적 유리한 조건하에서 단량제 디하이드로시나피닉산으로 비합화되고 거듭 재중화된다.

<table><tbody><tr><td>&lt;strong&gt;Reaction 1: Green Knoevenagel condensation&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Ammonium bicarbonate</td><td>Sigma Aldrich</td><td>&gt;99%</td><td></td></tr><tr><td>Ethanol</td><td>Boom</td><td>Technical grade</td><td></td></tr><tr><td>Ethyl acetate</td><td>Macron</td><td>99.8%</td><td></td></tr><tr><td>Hydrochloric acid</td><td>Boom</td><td>37%</td><td></td></tr><tr><td>Malonic acid</td><td>Sigma Aldrich</td><td>99%</td><td>used as received</td></tr><tr><td>Sodium bicarbonate</td><td>Sigma Aldrich</td><td>&gt;99.7%</td><td></td></tr><tr><td>Syringaldehyde</td><td>Sigma Aldrich</td><td>98%</td><td>used as received</td></tr><tr><td>&lt;strong&gt;Reaction 2: Hydrogenation&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Magnesium sulfate</td><td>Macron</td><td>99%</td><td>dried</td></tr><tr><td>Raney&amp;trade; nickel</td><td>Sigma Aldrich</td><td>&gt;89%</td><td></td></tr><tr><td>Sodium hydroxide</td><td>Boom</td><td>Technical grade</td><td>dissolved</td></tr><tr><td>&lt;strong&gt;Reaction 3: Acetylation&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Acetic anhydride</td><td>Macron</td><td>&gt;98%</td><td></td></tr><tr><td>Acetone</td><td>Macron</td><td>&gt;99.5%</td><td></td></tr><tr><td>Sodium acetate</td><td>Sigma Aldrich</td><td>&gt;99%</td><td></td></tr><tr><td>&lt;strong&gt;Reaction 4A: Polymerisation&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>1,2-xylene</td><td>Macron</td><td>&gt;98%</td><td></td></tr><tr><td>Sodium hydroxide</td><td>Boom</td><td>Technical grade</td><td>finely powdered</td></tr><tr><td>Zinc(II)acetate</td><td>Sigma Aldrich</td><td>99.99%</td><td></td></tr><tr><td>&lt;strong&gt;Reaction 4B: Depolymerisation&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Sodium hydroxide</td><td>Boom</td><td>Technical grade</td><td>dissolved</td></tr><tr><td>Sulfuric acid</td><td>Macron</td><td>100%</td><td></td></tr><tr><td>&lt;strong&gt;Analysis&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>CDCl&lt;sub&gt;3&lt;/sub&gt;</td><td>Cambride Isotope Laboratories, Inc.</td><td>99.5%</td><td></td></tr><tr><td>CF&lt;sub&gt;3&lt;/sub&gt;COOD</td><td>Cambride Isotope Laboratories, Inc.</td><td>98%</td><td></td></tr><tr><td>Dimethylformamide</td><td>Macron</td><td>&gt;99.9%</td><td></td></tr><tr><td>Hexafluoro-2-propanol</td><td>TCI Chemicals</td><td>&gt;99%</td><td></td></tr><tr><td>Methanol</td><td>Macron</td><td>&gt;99.8%</td><td></td></tr><tr><td>Tetrahydrofuran</td><td>Macron</td><td>&gt;99.9%</td><td></td></tr></tbody></table>

designed for molecular recycling: a lignin-derived semi-aromatic biobased polymer

화학적으로 재활용 가능한 바이오 폴리머의 개발은 순환 경제를 추구하는 기회를 제공합니다. 화학적으로 재활용 가능한 바이오폴리머는 사용 단계 후 폐기 단계에서 폴리머 물질의 문제를 해결하기 위해 긍정적인 노력을 기울입니다. 본 논문에서, 리닌과 같은 바이오매스로부터 완전히 추출될 수 있는 생체 기반 반 방향족 폴리에스테르의 생산이 설명되고 시각화된다. 이 백서에 기재된 폴리머 폴리-S는 PET와 같은 특정 일반적으로 사용되는 플라스틱과 유사한 열 특성을 갖는다. 우리는 방향족 알데히드와 말론산에서 단량체를 효율적으로 생산할 수 있는 녹색 Knoevenagel 반응을 개발했습니다. 이 반응은 확장 가능한 것으로 입증되었으며 현저하게 낮은 계산 된 전자 계수를 가지고 있습니다. 리그노 파이토케미칼이 있는 폴리에스테르는 최소한의 손실로 효율적인 분자 재활용을 보여줍니다. 폴리에스테르 폴리(dihydrosinapinicacid) (poly-S)는 이러한 반 방향족 폴리에스테르의 예로 제시되고, 중합화, 비합합화 및 재중합이 설명된다.

시나피닉산은 그린 크노벤나겔 응축을 이용하여 주사기알데히드로부터 고순도 및 고수율(> 95%)으로 합성되었다. (지원 정보: 그림 S1) E-팩터는 폐기물 생산의 지표로, 더 많은 수의 폐기물이 더 많은 폐기물을 나타냅니다. E-계수는 총 재료 입력을 취하고 원하는 최종 제품의 양을 빼고 전체를 최종 제품의 양으로 나누어 계산합니다. 이 녹색 Knoevenagel 응축은 계산할 수 있는 1.0의 E 계수...

Watch this Scientific Journal Video about Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer at JoVE.com

Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer

원형 재료 경제에 대한 폐쇄 루프 접근 방식의 예는 여기에 설명되어 있습니다. 전체 지속 가능한 주기는 생물 기반 반 방향족 폴리 에스테르는 중합, 폴리머화에 의해 설계 된 다음 수확량 또는 최종 특성에 약간의 변화만으로 다시 중합화되는 곳을 제시합니다.

분자 재활용을 위해 설계: 리닌 유래 반 방향족 생물 기반 폴리머

The development of chemically recyclable biopolymers offers opportunities within the pursuit of a circular economy. Chemically recyclable biopolymers make ...

designed-for-molecular-recycling-lignin-derived-semi-aromatic

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Organic Chemistry

Chemistry

Unit 1

&alpha;-Carbon Chemistry: Enols, Enolates, and Enamines

SCIENTISTS IN ACTION

3.4K 조회수.  Avans University of Applied Science. 원형 재료 경제에 대한 폐쇄 루프 접근 방식의 예는 여기에 설명되어 있습니다. 전체 지속 가능한 주기는 생물 기반 반 방향족 폴리 에스테르는 중합, 폴리머화에 의해 설계 된 다음 수확량 또는 최종 특성에 약간의 변화만으로 다시 중합화되는 곳을 제시합니다.

비디오: Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer

Methods for Facilitating Microbial Growth on Pulp Mill Waste Streams and Characterization of the Biodegradation Potential of Cultured Microbes

The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high quality paper. Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. However, the recalcitrant nature of the lignocellulose resources, its chemical derivatives that constitute the majority of available organic carbon within black liquor, and its basic pH present challenges to microbial biodegradation of this waste material. Methods for the collection and modification of black liquor for microbial growth are aimed at utilization of this pulp waste to convert the lignin, organic acids, and polysaccharide degradation byproducts into valuable chemicals. The lignocellulose extraction techniques presented provide a reproducible method for preparation of lignocellulose growth substrates for understanding metabolic capacities of cultured microorganisms. Use of gas chromatography-mass spectrometry enables the identification and quantification of the fermentation products resulting from the growth of microorganisms on pulping waste. These methods when used together can facilitate the determination of the metabolic activity of microorganisms with potential to produce fermentation products that would provide greater value to the pulping system and reduce effluent waste, thereby increasing potential paper milling profits and offering additional uses for black liquor.

Industrial wastes can be collected and modified to analyze microbial growth. Lignocellulose extraction techniques provide components to analyze specific biodegradation ability. Gas chromatography-mass spectrometry identifies fermentation products of microorganisms grown on pulping waste. These methods determine the metabolic capacity of microorganisms to degrade pulping waste.

The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high ...

연구

환경과학

Towards Biomimicking Wood: Fabricated Free-standing Films of Nanocellulose, Lignin, and a Synthetic Polycation

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and lignin. Layer-by-layer (LbL) assembly process which relies on the assembly of oppositely charged molecules from aqueous solutions was used to build a freestanding composite film of isolated wood polymers of lignin and oxidized nanofibril cellulose (NFC). To facilitate the assembly of these negatively charged polymers, a positively charged polyelectrolyte, poly(diallyldimethylammomium chloride) (PDDA), was used as a linking layer to create this simplified model cell wall. The layered adsorption process was studied quantitatively using quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry. The results showed that layer mass/thickness per adsorbed layer increased as a function of total number of layers. The surface coverage of the adsorbed layers was studied with atomic force microscopy (AFM). Complete coverage of the surface with lignin in all the deposition cycles was found for the system, however, surface coverage by NFC increased with the number of layers. The adsorption process was carried out for 250 cycles (500 bilayers) on a cellulose acetate (CA) substrate. Transparent free-standing LBL assembled nanocomposite films were obtained when the CA substrate was later dissolved in acetone. Scanning electron microscopy (SEM) of the fractured cross-sections showed a lamellar structure, and the thickness per adsorption cycle (PDDA-Lignin-PDDA-NC) was estimated to be 17 nm for two different lignin types used in the study. The data indicates a film with highly controlled architecture where nanocellulose and lignin are spatially deposited on the nanoscale (a polymer-polymer nanocomposites), similar to what is observed in the native cell wall.

The objective of this research was to form synthetic plant cell wall tissue using layer-by-layer assembly of nanocellulose fibrils and isolated lignin assembled from dilute aqueous suspensions.&#160; Surface measurement techniques of quartz crystal microbalance and atomic force microscopy were used to monitor the formation of the polymer-polymer nanocomposite material.

Nanocellulose, 리그닌의 날조 된 자립형 필름, 및 합성 폴리 양이온 : Biomimicking 나무를 향하여

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and ...

화학

Pretreatment of Lignocellulosic Biomass with Low-cost Ionic Liquids

A number of ionic liquids (ILs) with economically attractive production costs have recently received growing interest as media for the delignification of a variety of lignocellulosic feedstocks. Here we demonstrate the use of these low-cost protic ILs in the deconstruction of lignocellulosic biomass (Ionosolv pretreatment), yielding cellulose and a purified lignin. In the most generic process, the protic ionic liquid is synthesized by accurate combination of aqueous acid and amine base. The water content is adjusted subsequently. For the delignification, the biomass is placed into a vessel with IL solution at elevated temperatures to dissolve the lignin and hemicellulose, leaving a cellulose-rich pulp ready for saccharification (hydrolysis to fermentable sugars). The lignin is later precipitated from the IL by the addition of water and recovered as a solid. The removal of the added water regenerates the ionic liquid, which can be reused multiple times. This protocol is useful to investigate the significant potential of protic ILs for use in commercial biomass pretreatment/lignin fractionation for producing biofuels or renewable chemicals and materials.

The pretreatment of lignocellulosic biomass with protic low-cost ionic liquids is shown, resulting in a delignified cellulose-rich pulp and a purified lignin. The pulp gives rise to high glucose yields after enzymatic saccharification.

저가 이온 성 액체와 리그 노 셀룰로오스 바이오 매스의 전처리

A number of ionic liquids (ILs) with economically attractive production costs have recently received growing interest as media for the delignification of ...

Extraction of Lignin with High &#946;-O-4 Content by Mild Ethanol Extraction and Its Effect on the Depolymerization Yield

Lignin valorization strategies are a key factor for achieving more economically competitive biorefineries based on lignocellulosic biomass. Most of the emerging elegant procedures to obtain specific aromatic products rely on the lignin substrate having a high content of the readily cleavable &#946;-O-4 linkage as present in the native lignin structure. This provides a miss-match with typical technical lignins that are highly degraded and therefore are low in &#946;-O-4 linkages. Therefore, the extraction yields, and the quality of the obtained lignin are of utmost importance to access new lignin valorization pathways. In this manuscript, a simple protocol is presented to obtain lignins with high &#946;-O-4 content by relatively mild ethanol extraction that can be applied to different lignocellulose sources. Furthermore, analysis procedures to determine the quality of the lignins are presented together with a depolymerization protocol that yields specific phenolic 2-arylmethyl-1,3-dioxolanes, which can be used to evaluate the obtained lignins. The presented results demonstrate the link between lignin quality and potential for the lignins to be depolymerized into specific monomeric aromatic chemicals. Overall, the extraction and depolymerization demonstrates a trade-off between the lignin extraction yield and the retention of the native aryl-ether structure and thus the potential of the lignin to be used as the substrate for the production of chemicals for higher-value applications.

Here, we present a protocol to perform ethanol extraction of lignin from several biomass sources. The effect of the extraction conditions on the lignin yield and &#946;-O-4 content are presented. Selective depolymerization is performed on the obtained lignins to obtain high aromatic monomer products.

온화한 에탄올 추출 및 Depolymerization 수율에 미치는 영향에 의해 높은 β-O-4 콘텐츠 리그 닌의 추출

Lignin valorization strategies are a key factor for achieving more economically competitive biorefineries based on lignocellulosic biomass. Most of the ...

Comprehensive Compositional Analysis of Plant Cell Walls (Lignocellulosic biomass) Part I: Lignin

The need for renewable, carbon neutral, and sustainable raw materials for industry and society has become one of the most pressing issues for the 21st century. This has rekindled interest in the use of plant products as industrial raw materials for the production of liquid fuels for transportation1 and other products such as biocomposite materials7. Plant biomass remains one of the greatest untapped reserves on the planet4. It is mostly comprised of cell walls that are composed of energy rich polymers including cellulose, various hemicelluloses (matrix polysaccharides, and the polyphenol lignin6 and thus sometimes termed lignocellulosics. However, plant cell walls have evolved to be recalcitrant to degradation as walls provide tensile strength to cells and the entire plants, ward off pathogens, and allow water to be transported throughout the plant; in the case of trees up to more the 100 m above ground level. Due to the various functions of walls, there is an immense structural diversity within the walls of different plant species and cell types within a single plant4. Hence, depending of what crop species, crop variety, or plant tissue is used for a biorefinery, the processing steps for depolymerization by chemical/enzymatic processes and subsequent fermentation of the various sugars to liquid biofuels need to be adjusted and optimized. This fact underpins the need for a thorough characterization of plant biomass feedstocks. Here we describe a comprehensive analytical methodology that enables the determination of the composition of lignocellulosics and is amenable to a medium to high-throughput analysis. In this first part we focus on the analysis of the polyphenol lignin (Figure 1). The method starts of with preparing destarched cell wall material. The resulting lignocellulosics are then split up to determine its lignin content by acetylbromide solubilization3, and its lignin composition in terms of its syringyl, guaiacyl- and p-hydroxyphenyl units5. The protocol for analyzing the carbohydrates in lignocellulosic biomass including cellulose content and matrix polysaccharide composition is discussed in Part II2.

Comprehensive Compositional Analysis of Plant Cell Walls Lignocellulosic biomass Part I: Lignin

Plant biomass is a major carbon-neutral renewable resource that could be used for the production of biofuels. Plant biomass consists mainly of cell walls, a structurally complex composite material termed lignocellulosics. Here we describe a protocol for a comprehensive analysis of the content and composition of the polyphenolic lignin.

식물 세포 벽의 종합 작곡 분석 (리그노셀룰로오스성 바이오 매스) 부 I : 리그닌

The need for renewable, carbon neutral, and sustainable raw materials for industry and society has become one of the most pressing issues for the 21st ...

생물학

Twin-Screw Extrusion Process to Produce Renewable Fiberboards

A versatile twin-screw extrusion process to provide an efficient thermo-mechano-chemical pre-treatment on lignocellulosic biomass before using it as source of mechanical reinforcement in fully bio-based fiberboards was developed. Various lignocellulosic crop by-products have already been successfully pre-treated through this process, e.g., cereal straws (especially rice), coriander straw, shives from oleaginous flax straw, and bark of both amaranth and sunflower stems.
The extrusion process results in a marked increase in the average fiber aspect ratio, leading to improved mechanical properties of fiberboards. The twin-screw extruder can also be fitted with a filtration module at the end of the barrel. The continuous extraction of various chemicals (e.g., free sugars, hemicelluloses, volatiles from essential oil fractions, etc.) from the lignocellulosic substrate, and the fiber refining can, therefore, be performed simultaneously.
The extruder can also be used for its mixing ability: a natural binder (e.g., Organosolv lignins, protein-based oilcakes, starch, etc.) can be added to the refined fibers at the end of the screw profile. The obtained premix is ready to be molded through hot pressing, with the natural binder contributing to fiberboard cohesion. Such a combined process in a single extruder pass improves the production time, production cost, and may lead to reduction in plant production size. Because all the operations are performed in a single step, fiber morphology is better preserved, thanks to a reduced residence time of the material inside the extruder, resulting in enhanced material performances. Such one-step extrusion operation may be at the origin of a valuable industrial process intensification.
Compared to commercial wood-based materials, these fully bio-based fiberboards do not emit any formaldehyde, and they could find various applications, e.g., intermediate containers, furniture, domestic flooring, shelving, general construction, etc.

A versatile twin-screw extrusion process to provide an efficient thermo-mechano-chemical pretreatment on lignocellulosic biomass was developed, which leads to an increased average fiber aspect ratio. A natural binder can also be added continuously after fiber refining, leading to bio-based fiberboards with improved mechanical properties after hot pressing of the obtained extruded material.

재생 가능한 섬유판 을 생산하는 트윈 나사 압출 공정

A versatile twin-screw extrusion process to provide an efficient thermo-mechano-chemical pre-treatment on lignocellulosic biomass before using it as ...

공학

Fractionation of Lignocellulosic Biomass using the OrganoCat Process

The shift from a petroleum-based to a more sustainable and bio-based economy requires the development of new refinery concepts to maintain the supply of raw materials and energy. For these novel and sustainable biorefinery concepts, it is important to use catalysts and solvents that are aligned with the principles of Green Chemistry. Therefore, the implementation of biogenic alternatives can be a promising solution. The lignocellulose pretreatment and fractionation process presented herein-OrganoCat-is an integrated fractionation of lignocellulose into its main components using biogenic acids such as 2,5-furandicarboxylic acid as catalyst. Hemicelluloses and other non-cellulosic polysaccharides are selectively depolymerized by the diluted acid and dissolved, while the crystalline cellulose remains in the solid pulp. In the presence of a second organic phase consisting of biogenic 2-methyltetrahydrofuran, disentangled lignin is extracted in situ. The process allows for the efficient fractionation of the three main components-lignin, cellulose, and non-cellulosic sugars. This helps to focus on the quality of the lignin, the improvement of enzymatic hydrolysis of the cellulose-enriched pulp, and the mild non-cellulosic sugar extraction with low degradation.

OrganoCat is a method for the pretreatment and fractionation of lignocellulose under mild conditions into lignin, fermentable sugars, and cellulose pulp. In a biogenic, biphasic solvent system of water and 2-methyltetrahydrofuran with 2,5-furancarboxylic acid as catalyst, the OrganoCat products are separated in situ for straightforward product recovery.

오가노캣 공정을 이용한 리뇨셀룰로오스 바이오매스의 분획

The shift from a petroleum-based to a more sustainable and bio-based economy requires the development of new refinery concepts to maintain the supply of ...

Ultrafast Lignin Extraction from Unusual Mediterranean Lignocellulosic Residues

Pretreatment is still the most expensive step in lignocellulosic biorefinery processes. It must be made cost-effective by minimizing chemical requirements as well as power and heat consumption and by using environment-friendly solvents. Deep eutectic solvents (DESs) are key, green, and low-cost solvents in sustainable biorefineries. They are transparent mixtures characterized by low freezing points resulting from at least one hydrogen bond donor and one hydrogen bond acceptor. Although DESs are promising solvents, it is necessary to combine them with an economic heating technology, such as microwave irradiation, for competitive profitability. Microwave irradiation is a promising strategy to shorten the heating time and boost fractionation because it can rapidly attain the appropriate temperature. The aim of this study was to develop a one-step, rapid method for biomass fractionation and lignin extraction using a low-cost and biodegradable solvent. 
In this study, a microwave-assisted DES pretreatment was conducted for 60 s at 800 W, using three kinds of DESs. The DES mixtures were facilely prepared from choline chloride (ChCl) and three hydrogen-bond donors (HBDs): a monocarboxylic acid (lactic acid), a dicarboxylic acid (oxalic acid), and urea. This pretreatment was used for biomass fractionation and lignin recovery from marine residues (Posidonia leaves and aegagropile), agri-food byproducts (almond shells and olive pomace), forest residues (pinecones), and perennial lignocellulosic grasses (Stipa tenacissima). Further analyses were conducted to determine the yield, purity, and molecular weight distribution of the recovered lignin. In addition, the effect of DESs on the chemical functional groups in the extracted lignin was determined by Fourier-transform infrared (FTIR) spectroscopy. The results indicate that the ChCl-oxalic acid mixture affords the highest lignin purity and the lowest yield. The present study demonstrates that the DES-microwave process is an ultrafast, efficient, and cost-competitive technology for lignocellulosic biomass fractionation.

Deep eutectic solvent-based, microwave-assisted pretreatment is a green, fast, and efficient process for lignocellulosic fractionation and high-purity lignin recovery.

특이한 지중해 리그놀룰로오스 잔류물에서 초고속 리닌 추출

Pretreatment is still the most expensive step in lignocellulosic biorefinery processes. It must be made cost-effective by minimizing chemical requirements ...

Quantitative 31P NMR Analysis of Lignins and Tannins

The development of sustainable biorefinery products is confronted, among others, with the challenge of lignin and tannin valorization. These abundant, renewable aromatic biopolymers have not been widely exploited due to their inherent structural complexity and high degrees of variability and species diversity. The lack of a defined primary structure for these polyphenols is further compounded with complex chemical alterations induced during processing, eventually imparting a large variety of structural features of extreme significance for any further utilization efforts.
Consequently, a protocol for the rapid, simple, and unequivocal identification and quantification of the various functional groups present in natural polyphenols, is a fundamental prerequisite for understanding and accordingly tailor their reactivity and eventual utility.
Quantitative 31P NMR offers the opportunity to rapidly and reliably identify unsubstituted, o-mono substituted, and o-disubstituted phenols, aliphatic OHs, and carboxylic acid moieties in lignins and tannins with broad application potential.
The methodology consists of an in situ quantitative lignin or tannin labeling procedure using a suitable 31P containing probe, followed by the acquisition of a quantitative 31P NMR spectrum in the presence of an internal standard. The high natural abundance of the 31P nucleus allows for small amounts of the sample (~30 mg) and short NMR acquisition times (~30-120 min) with well-resolved 31P signals that are highly dependent on the surrounding chemical environment of the labeled OH groups.

Quantitative 31P NMR Analysis of Lignins and Tannins

31P NMR is a powerful tool for the structural elucidation of polyphenols. This fast, easy, precise, quantitative, and highly reproducible analytical procedure, that allows for the quantification and differentiation of the different types of hydroxy, phenolic, and carboxylic groups in lignins and tannins has now become a routine analytical tool.

리닌과 탄닌의 정량적 31P NMR 분석

The development of sustainable biorefinery products is confronted, among others, with the challenge of lignin and tannin valorization. These abundant, ...

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

The growing consumption of synthetic polymers and the accumulation of polymer waste have led to a pressing need for new routes to sustainable materials. Achieving a closed-loop polymer economy via chemical recycling to monomer (CRM) is one such promising route. Our group recently reported a new CRM system based on polymers prepared by ring-opening metathesis polymerization (ROMP) of trans-cyclobutane fused cyclooctene (tCBCO) monomers. This system offers several key advantages, including the ease of polymerization at ambient temperatures, quantitative depolymerization to monomers under mild conditions, and a broad range of functionalities and thermomechanical properties. Here, we outline detailed protocols for the preparation of tCBCO-based monomers and their corresponding polymers, including the preparation of elastic polymer networks and compression molding of linear thermoplastic polymers. We also outline the preparation of high ring strain E-alkene tCBCO monomers and their living polymerization. Finally, the procedures for the depolymerization of linear polymers and polymer networks are also demonstrated.

Here, we describe protocols for the preparation of trans-cyclobutane fused cyclooctenes (tCBCO),&#160;their polymerization to prepare depolymerizable olefinic polymers, and the depolymerization of these polymers under mild conditions. Additionally, protocols for the preparation of depolymerizable networks and compression molding of rigid linear plastics based on this system are described.

융합 고리 사이클로옥텐 단량체를 기반으로 하는 해중합 가능한 올레핀 폴리머

The growing consumption of synthetic polymers and the accumulation of polymer waste have led to a pressing need for new routes to sustainable materials. ...