A kind of elastic body toughening polylactic acid coblended matter material and preparation method thereof with shape memory effectTechnical field
The invention belongs to macromolecular material and preparation field thereof, particularly relate to a kind of elastic body toughening polylactic acid coblended matter material and preparation method thereof with shape memory effect.
Background technology
20th century appearance and the fast development thereof of synthesized polymer material greatly improved human life, and synthesized polymer material has been listed as the four big pillars in material field with iron and steel, timber and cement.Yet the production and consumption that synthesized polymer material is huge has also produced two key subjects: the environmental pollution that limited petroleum resources are caused by mass consumption and waste polymer.These problems have caused global great attention.21 century many countries will build Sustainable development resource recycling society as one of state basic policy, development environment close friend's biodegradated polymer materal worldwide is surging forward.
High-molecular weight gathers D, and L one lactic acid (PLA), macromole are the unformed state of random winding, and its second-order transition temperature is about 55 ℃, and in the above 5-10 of second-order transition temperature ℃ scope, glassy transition is a rubbery state.In numerous biodegradated polymer materals of having developed, poly(lactic acid) (PLA) is described as one of the most potential kind.Main because PLA has fully biodegradable and be the plant origin of raw material with the renewable resources, and be a kind of material of keeping nature " carbon cycle balance ".So the Application and Development of PLA can reduce the white pollution of polymeric scrap material to environment, save petroleum resources, suppress to increase the aggravation of the global greenhouse effect that causes owing to the clean quantity discharged of carbonic acid gas.
PLA is used for biomedicine field the earliest, the mid-90 in 20th century is successfully developed as industrial stable performance and cheap PLA resin by U.S. Cargill company, and a large amount of work is being done by many subsequently developed countries especially Japan aspect the Application and Development of PLA.Now, PLA has been applied to coating, tackiness agent, fiber and plastics every field.Change short period commodity such as material by being used for bag at first, develop into the commodity that agricultural water industry, civil construction industry, daily living article etc. have longer life cycle, even be used as the weather resistance commodity of automobile, the contour performance of field of electronics.
In recent years, to the PLA Study on Shape Memory Effect seldom, the report of minority occurs with the form of patent.ShikinamiAngewandte Chemie-International Edition, 2005.44:p.1188-1192 the shape-memory material of being made up of poly(lactic acid) is studied, obtained having the poly(lactic acid) of shape memory effect, biological degradability and absorbability preferably simultaneously, find that the poly lactic acid series shape-memory material can both return to initial shape more than 60 ℃ soon, and all demonstrate than higher shape recovery ratio.
Yet, under the PLA normal temperature a kind of hard and crisp material, flexibility and shock resistance are poor, and extension at break has only about 1-5%, and this inherent fragility has limited the range of application of PLA shape memory effect.If therefore PLA is under higher stretch ratio, demonstrating its excellent shape memory effect must carry out toughening modifying to PLA.PLA is carried out toughening modifying, mainly contain two kinds of methods of modification by copolymerization and blending and modifying at present.And blending and modifying possesses skills simply, economical and be easy to advantage such as industrialization, therefore attract investigator's concern more.Polymer International such as Zhang, 2004.53 (6):, and furtherd investigate the mechanical property of blend p.716-722 with branch-shape polymer and PLA blend.MacromolecularMaterials and Engineering such as Wong, 2004.289 (5):, improve extension at break and reach original 314%, and studied its mechanism of fracture p.447-456 with hyperbranched thing, flax fiber and PLA blend.Carbohydrate Polymers such as Ren, 2008.2008 (74): p.79-85 prepared poly(lactic acid)/terephthalic acid-hexanodioic acid-1 with extrusion by melting, 4-butyleneglycol terpolymer (PLA/PBAT) blend has been studied mechanical property, rheological property, thermal characteristics and the consistency of polylactic acid blend.The result shows that at PBAT content be at 30% o'clock, and the elongation at break maximum reaches 9%.Macromolecules such as Lin, 2007.40 (17): p.6257-6267 adopt the method for hyperbranched polydactyl acid, with hyperbranched polymer and poly(lactic acid) melt blending.Not only improve the toughness of poly(lactic acid), made its extension at break can reach 50%, also reduced the melt viscosity of poly(lactic acid) simultaneously, improved processing characteristics.Macromolecular Bioscience such as Hiroshi, 2007.7 (7): p.921-928 use Biodegradable polyurethane (PU) and PLA melt blending, PU is dispersed in micro-meter scale and plays the energy dispersive effect among the PLA, and the blend of preparing has good toughness.But it is big that present domestic and international research ubiquity the second material addition, the problem that elongation at break is not high.Generally between 10-50%, the extension at break of blend is generally between 10-50% for the second material addition.Adopt which kind of material and PLA blend, come the more effective PLA toughness of improving, have good shape memory effect simultaneously, be still urgent problem.(English is direct)
Polyamide elastomer is the multipolymer of a kind of polytetrahydrofuran or polyoxyethylene and nylon 6 ornylon 12, and main chain contains ehter bond and amido linkage.Polyamide elastomer and poly(lactic acid) belong to half-phase and hold system, and polytetrahydrofuran plays the effect that increases consistency.The adding of polyamide elastomer can increase the toughness of poly(lactic acid), makes it have higher elongation at break and shock resistance.
The general molecular formula of polyamide elastomer is as follows:
Summary of the invention
Technical problem to be solved by this invention provides a kind of elastic body toughening polylactic acid coblended matter material with shape memory effect and preparation method thereof, the poly-lactic acid material of this method preparation has very high toughness and elongation at break, than under do not rupture at Gao Lashen, can return to original shape by heating, demonstrate good memory effect.
A kind of elastic body toughening polylactic acid coblended matter material with shape memory effect of the present invention comprises that molecular weight is 80000-200000 poly(lactic acid) and polyamide elastomer, and its weight ratio is 70-95:5-30.
Described poly(lactic acid) and polyamide elastomer weight ratio are 90-95:5-10.
Described polyamide elastomer is the multipolymer of polytetrahydrofuran and nylon 6, polytetrahydrofuran andnylon 12, polyoxyethylene and nylon 6 or polyoxyethylene andnylon 12, and main chain contains ehter bond and amido linkage, is preferably the PEBAX of Arkema company.
A kind of preparation method with elastic body toughening polylactic acid coblended matter material of shape memory effect of the present invention comprises the following steps:
(1) with polyamide elastomer and poly(lactic acid) 70-95:5-30 blend by weight, blending temperature is 160-180 ℃, and screw speed is 30-70r/min, and the blend time is 5-10min;
(2) with blend 160-180 ℃ of following injection moulding, make thick 1mm, the dumbbell shape mechanics batten of length 8cm.
Mass ratio when described step (1) polyamide elastomer and polylactic acid blend is 5%, 10%, 20% or 30%.
Described step (1) blending temperature is 180 ℃, and screw speed is 50r/min, and the blend time is 5 minutes.
Described step (2) injection moulding temperature is 175 ℃.
The molecular weight of poly(lactic acid) of the present invention is 80000-200000, and fusing point is 140-170 ℃, and second-order transition temperature is 50-60 ℃, and the deformation recovery temperature is low, wide application.Polyamide elastomer plays toughness reinforcing purpose as additive, can adopt (1) European Polymer Journal,Volume 13, Issue 5,1977, the method of Pages 343-351 bibliographical information is prepared, be summarized as follows: with relative molecular mass is the poly suboxygen alkyl dibasic alcohol of 200-3000, is that the both-end carboxyl polyamides of 800-5000 carries out the melt phase polycondensation reflection and can obtain polyamide elastomer as polyethylene oxide dibasic alcohol, poly(propylene oxide) dibasic alcohol or polytetrahydrofuran dibasic alcohol and relative molecular weight.Temperature of reaction is 200-300 ℃, vacuum tightness<267Pa, reflection time〉2h, add four alkoxide compound class catalyzer and can improve speed of response, increase the molecular weight of resulting polymers.(2) also can adopt commercially available commercially produced product, be the product of PEBAX2533, PEBAX4033, PEBAX5533, PEBAX1074 or PEBAX4011 as the Atofina Chemicals company trade mark.
Performance test with elastic body toughening polylactic acid coblended matter of shape memory effect utilizes electronic tensile machine to carry out stretching experiment the dumbbell shape mechanics batten of above-mentioned preparation, chuck spacing 30mm, draw speed 5mm/min.
The shape memory function of shape-memory polymer is mainly derived from material internal exists not exclusively compatible two-phase---keep the stationary phase of moulding article shape and vary with temperature but softening-reversible change anti-phase of sclerosis can take place.Change rubbery state poly(lactic acid) (PLA) under the effect of external force, the elongation of material causes the spatial arrangement of molecular chain that directivity has been arranged, making molecular chain have to unfold along the direction of external force field comes, when this when being deformed into the shape of expectation, under the condition that keeps stress, with material cooled, but anti-phase enters vitreous state, molecular chain is frozen, and hardened material becomes stable solid shaped bodies; On the other hand, because macromolecular entanglement has stoped intermolecular slippage, solid shaped bodies after distortion is when being heated to rubbery state, thermal motion tries hard to make the molecular chain disordering, so that be returned to rolled state, this has just formed restorer, and the solid shaped bodies after the distortion returns to original shape, has promptly finished a memory circulation.
The present invention carries out blend by the ratio that changes polyamide elastomer and poly(lactic acid), can control the multiple performance of product, as second-order transition temperature, and mechanical strength, extension at break etc.General poly-lactic acid material is being stretched or during stress in bending, is being easy to fracture.The poly-lactic acid material of the present invention's preparation has overcome the more crisp shortcoming of pure poly(lactic acid), has very high toughness and elongation at break.Therefore under high stretch ratio, do not rupture, can return to original shape, demonstrate good shape memory effect by heating.
Description of drawings
Fig. 1 is the SEM photo.
Fig. 2 is the DMA test result.
Fig. 3 is a mechanical curves.
Fig. 4 is a shape memory restorability photo.
Fig. 5 is stretching for the first time and the photo that recovers the back secondary stretch.
Fig. 6 is the shape memory effect synoptic diagram.
Embodiment
Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiment only to be used to the present invention is described and be not used in and limit the scope of the invention.Should be understood that in addition those skilled in the art can make various changes or modifications the present invention after the content of having read the present invention's instruction, these equivalent form of values fall within the application's appended claims institute restricted portion equally.
Embodiment 1
Select the PEBAX 2533 of Arkema company for use, by weight 5% and poly(lactic acid) (molecular weight 80000) blend in Haake blend instrument.Blending temperature is 180 ℃, and screw speed is 50r/min, and the blend time is 5 minutes.
Blend 175 ℃ of following injection mouldings, is made thick 1mm, the dumbbell shape mechanics batten of length 8cm.Then blend is placed crystallization in about 30 minutes typing in 110 ℃.Tensile strength is 48.11MPa, and extension at break is 161.47%, the recovery extent 99% understretch ratio 100% situation.
The DMA curve is seen Fig. 2, and the SEM photo is seen Fig. 1 b, and mechanical property is seen Fig. 3 a, shape memory effect synoptic diagram 6.
Embodiment 2
Select the PEBAX 2533 of Arkema company for use, byweight 10% and poly(lactic acid) (molecular weight 100000) blend in Haake blend instrument.Blending temperature is 180 ℃, and screw speed is 50r/min, and the blend time is 5 minutes.
Blend 175 ℃ of following injection mouldings, is made thick 1mm, the dumbbell shape mechanics batten of length 8cm.Then blend is placed crystallization in about 30 minutes typing in 110 ℃.Tensile strength is 40.94MPa, and extension at break is 194.58%, the recovery extent 98% understretch ratio 100% situation.
The DMA curve is seen Fig. 2, and the SEM photo is seen Fig. 1 c, and mechanical property is seen Fig. 3 a, and shape memory recovers photo and sees Fig. 4, shape memory effect synoptic diagram 6.
Embodiment 3
Select the PEBAX 2533 of Arkema company for use, byweight 20% and poly(lactic acid) (molecular weight is 120000) blend in Haake blend instrument.Blending temperature is 180 ℃, and screw speed is 50r/min, and the blend time is 5 minutes.
Blend 175 ℃ of following injection mouldings, is made thick 1mm, the dumbbell shape mechanics batten of length 8cm.Then blend is placed crystallization in about 30 minutes typing in 110 ℃.Tensile strength is 23.69MPa, and extension at break is 184.62%, the recovery extent 94% understretch ratio 100% situation.
The DMA curve is seen Fig. 2, and mechanical property is seen Fig. 3 b, and shape memory effect is seen Fig. 6.
Embodiment 4
Select the PEBAX 2533 of Arkema company for use, byweight 30% and poly(lactic acid) (molecular weight 200000) blend in Haake blend instrument.Blending temperature is 180 ℃, and screw speed is 50r/min, and the blend time is 5 minutes.
Blend 175 ℃ of following injection mouldings, is made thick 1mm, the dumbbell shape mechanics batten of length 8cm.Then blend is placed crystallization in about 30 minutes typing in 110 ℃.Tensile strength is 24.58MPa, and extension at break is 367.17%, the recovery extent 90% understretch ratio 100% situation.
The DMA curve is seen Fig. 2, and mechanical property is seen Fig. 3 b, and shape memory effect is seen Fig. 6.
The various performance parameters of table 1 polylactic acid blend