《绿色化学原则》PPT课件.ppt

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1、綠色化學的原則Anastas&Warner(1998)的十二條原則(化工技術,9(12),128,2001)盡量避免廢棄物的生成,從源頭源頭防治污染 盡量使得製程中所採用的原料,進入最終產品之中 盡量使得所使用與產生的物質對人體健康和環境無毒無害 盡量使得產品具有高效的功能與最低的毒性 盡量避免使用溶劑,分離試劑等助劑,如不可避免時,也要選用無毒無害的助劑綠色化學的原則綠色化學的原則(2)盡量降低製程的能耗,最好在溫和的溫度與壓力下進行 在技術可行和經濟合理的前提下,降量採用可再生資源代替消耗性資源 盡量避免使用與產生不必要的衍生物 盡量選用高選擇性的催化劑,這比使用化學劑量助劑更優越 改用溫

2、和的生物製程(酵素:生物觸媒)進量使產品在其成功終結後,不會永存於環境中,要能分解成無害的物質 綠色化學的原則綠色化學的原則(3)儘量在製程中即時線上監控,有可能產生的有害物質,並儘量避免產生這些有害物質 儘量使用與產生可降低意外事故如洩漏,爆炸,火災等的化學品綠色化學Green Chemistry替代性原料無毒性/低毒性替代性溶劑H2O新觸媒更有效率生物程序生物觸媒替代性產品提升製程效率Design Safer Chemicals藉由分子設計概念,使用各種合成化學(organic/inorganic)得到比較安全的化學品。早期focus:efficacy of chemicals,i.e.效

3、用好,成本低;如今修正為:必須注重對環境與與健康安全的影響與衝擊(or 毒性毒性)Green Chemistry is a source prevention approach;new chemical structural design safe and efficacious existing chemicals(toxic)structural redesign safe and efficaciousGeneral ApproachesReducing absorption;Use of toxic mechanismUse of structural-activity relatio

4、nshipUse of isosteric replacementUse of retrometabolic designIdentification of equally efficacious,less toxic chemical substitutesElimination of the need for associated toxic substancesACS,640,1996減少吸收減少吸收 降低效應降低效應 毒性物質之生物化學:知其原因,才有對策影響吸收的因素:physicochemical factors molecular size,MW,dissociation con

5、stant,solubility,lipophilicity,physical state(G,L or S),particle size;細胞膜內含有lipid,所以lipid solubility 在腸胃內吸收角色重要;表面積(m2)吸收層厚度(m)血流速(L/min)皮膚 小腸 肺部 Designing safer chemicals,ACS 640,1996Toxic MechanismElectrophilic chemical substancesElectrophilic metabolites(from metabolism)Reactions with nucleophile

6、sWith defensive systemReactions with nucleophilesOf non-defensive cellularMolecules,DNA,RNA,etc excretion toxicityPath I Path IIStructural Modifications1-(alkoxy)-2-propanolR-O-CH2-C(CH2)-HOH1-(alkoxy)-1-propanolR-O-CH(CH2)-CH2OHNo toxicityToxicityHexane2,5-dimethyl hexaneNeurotoxicityNo toxicity ex

7、pected;BP增加40oC藉由改變新陳代謝路徑達成降低毒性效果Use of Structure-Activity Relationship 近年來分子模擬的主要工作;sometimes called structure property relationship;From qualitative relationship to quantitative structure activity relationships(QSAR);後者定量關係之建立可以靠(i)correlation;or(ii)molecular simulation;用於發展藥物的技巧Some ExamplesPolye

8、oxylated nonylphenols:as surfactants/emulsifiers;Glycidyl ethers:as reagents for synthesis;Isosteric Replacements 一個新的定義:isosteres chemical substances,atoms,or substituents that possess near equal or similar molecular shape and volume,approximately the same distribution of electrons,and which exhibi

9、t similar physicochemical properties.範例:三者皆為液體,12&41 沸點皆為 81oC;Metallized azo dyes:M=Cr(toxic)M=Fe 色澤類似,但不具毒性Other Techniques retrometabolic design:soft drug 觀念,i.e.該物質很容易被新陳代謝作用轉換掉,e.g.hydrolysis step;因而毒性降低 Equally useful,less toxic substitutes:例如 acetoacetate 取代isocyanate in sealant and adhesive;

10、isothiazolones for organotin as antifoulant for ships;等 Elimination of the need for associated toxic substances:該物質本身無毒,但其輸送儲存時會用到毒性物質,e.g.油漆,水性比油性好,no or less VOC;Designing Biodegradable Chemicals p.157-171,ACS 640,1996;Microbial degradation is the major loss mechanism for most organic chemicals;一般

11、會增加生物分解阻力者:(a)含鹵素,esp.Cl,F;(b)太多支鏈,branched,such as quaternary C or tertiary N;(c)nitro-,nitroso-azo-arylamino groups;(d)polycyclic residues,尤其是超過三個以上;(e)aliphatic ether bonds,C-O-C;生物法合成的東西大概都可以被生物分解;Biodegradable Chemicals(2)比較喜歡:引入oxygen in the form of hydroxyl,aldehydic,carboxylic;unsubstituted linear alkyl chains(4)and phenyl rings;TPBS:tetrapropylene akylbenzene sulfonate;LAS:linear alkylbenzene sulfonate後者比前者容易被生物分解(一般用途:清潔劑)前:Ethoxylated ethanaminium quaternary ammonium salt後:ester analog of previous compound;比較容易為生物分解