【作者】 赵亮；

【导师】 那辉；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2020， 硕士

【摘要】 聚氨酯材料在当今社会生活中扮演着重要的角色,在家居、交通、建筑和体育领域等都能找它的身影。聚氨酯材料普遍有着硬度高、弹性佳、耐老化、耐磨、耐低温等优点,同时,不同分子结构和化学组成的聚氨酯材料又有着各自的特性。因此,聚氨酯材料可以满足多种多样的需求。聚氨酯材料功能和特性的多样性要归因于其合成原料的选择多样性。虽然聚氨酯的合成原料从种类上来看,主要只包括二异氰酸酯、多元醇和扩链剂三大类。但是,如果在每一类合成原料中选择不同的单体就可以改变聚氨酯材料的性能。比如,选择芳香类二异氰酸酯的聚氨酯材料要比使用脂肪类的二异氰酸酯聚氨酯材料的力学强度更高,但是更容易泛黄;由聚醚多元醇合成的聚氨酯材料要比由聚酯多元醇合成的聚氨酯材料柔性更好,但是耐氧化性差;选择二元胺类扩链剂的聚氨酯材料要比选择二元醇类扩链剂的聚氨酯材料的分子极性更强,并可以形成更多的氢键。氢键起着物理交联作用,氢键越多,分子间作用力越强,聚氨酯材料强度越高。除此之外,每一种合成原料的结构,分子量等自身性质也可能影响聚氨酯材料的性能。同时,在合成过程中加入的各种改性剂或助剂等,也都会对聚氨酯材料的性能造成一定的影响。因此,聚氨酯材料可以有繁多的品种和丰富的特性。丙烯酸酯改性水性聚氨酯涂料是一种有代表性的聚氨酯材料,其结构特点是在聚氨酯分子链末端用丙烯酸酯进行封端。末端丙烯酸酯上带有的双键结构可以在紫外光的照射下发生交联反应,从而使液体涂料固化成膜。这样保证了在使用较少溶剂的情况下,就可以使涂料在保存、运输和使用前都处于液体状态,而使用时可以快速成膜,达到涂料的功能。因此,这类产品被认为是一种环境友好型的涂料。从丙烯酸酯改性水性聚氨酯涂料的使用过程上来看,在聚氨酯分子链末端引入丙烯酸酯结构,经过紫外光辐照就可以使其从液态转变为固态。我们受此启发,猜想如果在聚氨酯主体结构中引入丙烯酸酯结构单元,通过调节其在聚合物中的含量,以及紫外光辐射时间的长短来调控聚氨酯的交联程度,就可以较精细地调控聚氨酯的性能。本论文以此为出发点,尝试合成丙烯酸型嵌段聚氨酯,并详细地研究其结构与性能的关系。首先,我们选择使用六亚甲基二异氰酸酯(HDI),聚己内酯(PCL),3,3′,5,5′-四甲基联苯二酚型丙烯酸树脂(TMBPEA)为原料,通过调控投料比例,合成一系列丙烯酸型嵌段聚氨酯,并对其进行紫外光辐照固化处理。X射线衍射和拉伸等测试结果表明:通过调节合成原料的投料比例和调控侧链双键的交联程度来可以影响本论文中所制备的聚氨酯的结晶能力,从而影响其力学性能。随着PCL投料比例的增加,聚氨酯材料的结晶度从33.01%增加到69.60%,杨氏模量从89.79±5.74 MPa增加到224.88±5.22 MPa,拉升强度从9.04±1.26 MPa增加到12.98±0.33 MPa,断裂伸长率从499.09±88.38%增加到776.51±67.39%。同时,聚氨酯材料的形状恢复率从6.2%增加到86.2%。而经过紫外光辐照固化后,随着辐照时间的增加,聚氨酯材料的凝胶含量从37.94±0.56%增加到69.30±1.08%,结晶度从64.12%下降到25.81%,杨氏模量从104.27±7.01 MPa下降到18.74±1.30 MPa,拉伸强度从14.06±0.94 MPa下降到7.27±1.48 MPa,断裂伸长率从55.44±3.78%增长到68.22±11.43%。因此,我们认为可以通过以调节投料比例为主,调控交联程度为辅的方式,较精细地调控聚氨酯材料的力学性能。其次,在使用较低PCL分子量合成丙烯酸型嵌段聚氨酯后,与投料比例相同的含有较高PCL分子量的同种聚氨酯材料相比,聚氨酯材料的结晶度增加至49.01%,杨氏模量,拉伸强度和断裂伸长率分别降低至142.98±2.46 MPa,7.83±0.12 MPa和246.52±115.88%,形状恢复率为86.7%。在此基础上,我们使用4,4′-二环己基甲烷二异氰酸酯(HDMI)代替六亚甲基二异氰酸酯(HDI),用间三氟甲基苯基对苯二酚型丙烯酸树脂(3F-PQEA)和1,1,1-三(4-羟苯基)乙烷(THE)分别代替3,3′,5,5′-四甲基联苯二酚型丙烯酸树脂(TMBPEA),通过控制变量的方式,探究不同化学结构对聚氨酯材料性能的影响。我们发现,在配料比相同的情况下,用HMDI替换HDI引入脂肪环结构后,聚氨酯材料的结晶度从45.21%下降到32.95%,杨氏模量从189.93±13.37 MPa下降到19.81±5.27 MPa,拉伸强度从11.36±2.23 MPa下降到6.37±1.46 MPa,断裂伸长率从537.77±104.26%下降到527.25±178.08%,而形状恢复率为41.0%。用3F-PQEA替换TMBPEA,在保持苯环含量的同时,在侧链引入苯环结构后,聚氨酯材料的结晶度下降到5.51%,同时杨氏模量,拉伸强度分别降到1.52±0.13 MPa和4.64±0.87 MPa,而断裂伸长率增加到804.57±63.34%,形状恢复率为68.4%。在使用THE替换TMBPEA后,聚氨酯材料成为交联型聚合物后,我们发现聚氨酯材料的结晶度和杨氏模量分别下降到5.30%和5.64±0.26MPa,拉伸强度和断裂伸长率分别增加到17.31±3.65 MPa和640.27±73.66%,形状恢复率为13.4%。以上结果说明,降低PCL的分子量、引入脂肪环结构和在保证苯环含量基本不变的同时在支链上引入苯环,都将降低聚氨酯材料的力学性能。交联型聚氨酯与丙烯酸型嵌段聚氨酯相比,韧性更强。更多还原

【Abstract】 Polyurethane materials play an important role in today’s social life.It can be found in the fields of house furnishing,transportation,architecture,sporting and so on.Polyurethane materials generally have high hardness,good elasticity,aging resistance,wear resistance,low temperature resistance and other advantages.And various polyurethane materials have their own characteristics;therefore,polyurethane materials can meet a variety of needs.The diversity of functions and properties of polyurethane materials are attributed to the diversity of choice of synthetic materials.Although there are mainly three types of polyurethane synthetic materials,including diisocyanates,polyols and chain extenders,the selection of different monomers in each category may change the properties of polyurethane materials.For example,polyurethane materials synthesized from aromatic diisocyanates are stronger than those with aliphatic diisocyanates,but they are more prone to yellowing.Polyurethane materials synthesized from polyether polyols are more flexible than those synthesized from polyester polyols,but they have poor oxygen resistance.And polyurethane materials with binary amine chain extenders have stronger molecular polarity and can form more hydrogen bonds than those with dialcohol chain extenders.In addition,the structure,molecular weight and other properties of each synthetic material may also affect the properties of polyurethane materials.At the same time,modifiers and various additives added in the synthesis process will have a certain impact on the properties of polyurethane materials,so polyurethane materials can have a wide variety of characteristics for many applications.There is a polyurethane material called acrylate modified waterborne polyurethane coating.It is featured by the introduction of acrylic structure at the end of polyurethane chain.In this way,the double bonds attached to the polymer backbone could induce crosslinking reaction under ultraviolet light,thus solidifying the liquid coating into a film.This ensures that with use of less solvent,coating can be liquid in the preservation,transport and before being used,but it can be shaped into films after being used to achieve the function of the coating.This product is considered to be an environmentally friendly coating.From the perspective of the application process of acrylate modified waterborne polyurethane coating,acrylic structure is only introduced at the end of the polyurethane molecular chain,which can be transformed from liquid to solid under ultraviolet light.We were inspired by that,it is suggested that if acrylic acid structure is introduced into the main structure of polyurethane,its properties can be regulated by adjusting its content and controlling its crosslinking degree.Based on this,this thesis attempts to synthesize acrylate type polyurethane and study the relationship between structure and properties of polyurethane.First,we chose hexamethylene diisocyanate(HDI),polycaprolactone(PCL),3,3’,5,5’-tetramethyldiphenyl acrylate resin(TMBPEA)as the raw materials to synthesize a series of polyurethane with double light energy acrylate by adjusting the feed ratio,and then treated them by UV crosslinking.After that,we performed X-ray diffraction test,tensile test and so on to find that the crystallization property of polyurethane in this thesis could be affected by adjusting the feeding ratio of raw materials and controlling the crosslinking degree,thus affecting its’ tensile property.With the increase of PCL feeding proportion,the degree of crystallinity of polyurethane increases from 33.01% to 69.60%,Young’s modulus increases from 89.79±5.74 MPa to 224.88±5.22 MPa,tensile strength increases from 9.04±1.26 MPa to 12.98±0.33 MPa,and strain at break increases from 499.09±88.38% to 776.51±67.39%.Meanwhile,the shape recovery rate of polyurethane increases from 6.2% to 86.2%.After UV crosslinking,the crosslinking degree of polyurethane increases from 37.94±0.56% to 69.30±1.08%,the degree of crystallinity decreases from 64.12% to 25.81%,Young’s modulus decreases from 104.27± 7.01 MPa to 18.74± 1.30 MPa,the tensile strength decreases from 14.06± 0.94 MPa to 7.27± 1.48 MPa,and stain at break increases from 55.44±3.78% to 68.22±11.43%.Therefore,we believed that we could control the properties of polyurethane materials more precisely by controlling the feed ratio and the degree of crosslinking.Secondly,we used PCL with lower molecule weight to synthesize the same kind of polyurethane.Compared with the one which had same feed ratio but higher molecule weight of PCL,the degree of crystallinity of polyurethane with lower molecule weight of PCL decreases to 49.01%.And Young’s modulus,tensile strength and stain at break decreases to 142.98±2.46 MPa,7.83±0.12 MPa and 246.52±115.88% respectively,and the shape recovery rate is 86.7%.On this basis,we used dicyclohexylmethane 4,4’-diisocyanate(HDMI)instead of hexamethylene diisocyanate(HDI),and(3-trifluoromethyl)phenyl hydroquinone epoxy arylate resin(3F-PQEA)and 1,1,1-tris(4-hydroxyphenyl)ethane(THE)instead of 3,3’,5,5’-tetramethybiphenyl epoxy arylate(TMBPEA)respectively,in order to explore the influence of different structure on the properties of polyurethane materials.We found that,after replacing HDI with HMDI to introduce aliphatic ring structure,the degree of crystallinity of polyurethane decreases from 45.21% to 32.95%,Young’s modulus decreases from 189.93± 13.37 MPa to 19.81± 5.27 MPa,tensile strength decreases from 11.36± 2.23 MPa to 6.37± 1.46 MPa,the strain at break decreases from 537.77±104.26% to 527.25±178.08%,and the shape recovery rate is 41.0%.After replacing TMBPEA with 3F-PQEA for changing the position of benzene ring while maintaining the content of benzene ring,the degree of crystallinity of polyurethane decreases to 5.51%,in the meantime,Young’s modulus and tensile strength respectively decrease to 1.52± 0.13 MPa and 4.64± 0.87 MPa,but strain at break increases to 804.57±63.34%,and the shape recovery rate is 68.4%.And after replacing TMBPEA with THE,the polyurethane material becomes crosslinked polymers.We found that the crystallinity and Young’s modulus of polyurethane decrease to 5.30% and 5.64±0.26 MPa,the tensile strength and strain at break increase to 17.31±.65 MPa and 640.27±73.66%,and the shape recovery rate is 13.4%.The above results show that the reducing molecular weight of PCL,the introduction of the structure of aliphatic ring structure and the introduction of the benzene ring on the branched chain while ensuring the content of the benzene ring is basically unchanged will reduce the mechanical properties of polyurethane materials.Compared with acrylate polyurethane block copolymers,crosslinked polyurethane has better toughness.更多还原