Shanghai Daoqin Plastics Co., Ltd.

TPU brief introduction

thermoplastic polyurethane (TPU) 简称TPU, also 称PU hot plastics, is types oligomer more alcohol soft and 二异氰 acid ester - expand agent hard formed property copolymer.

TPU separation inner has -NH-COO-基团, its very more features 取决于 long binary alcohol types type, its hardness use hard ratio/proportion adjustment, it light aging property can add light stabilizer add improvement, meanwhile 也取决于异氰 acid ester is aromatic also is aliphatic.

aliphatic and aromatic 差别

aromatic acid ester used for in outer light 照射会 oxidation color combined. use aromatic poly acid ester made polyurethane ester coating material easy by oxidation, therefore, in cationic light lower, more easy 退化.

and versus 反, aliphatic acid ester main/primary used for manufacturing light stabilization coating material. in need for outer light or day light stabilization combined, automotive and many water property formulation in, use this category of product.

aliphatic acid ester

aliphatic poly acid ester make polyurethane ester coating material has chemical resistance and good resistant aging property. due to 不含苯基团, aliphatic acid ester application ensure in poor conditions lower 持久附 force.

aromatic acid ester

and aliphatic material versus ratio, this type product material make coating material resistant aging property 差（ yellowing ）, chemical resistance 差（ especially is relatively resistant alkali property ）. therefore aromatic poly acid main/primary by used for inner （ sheet/plate coating material, coating material and other ） or used for 底漆. make is 底漆, in automotive field/area use 越 越 less, is 底漆 泛黄会 effect/influence color, 并引起层间剥离.

generally 说, aromatic poly acid ester non main/primary used for coating material. ratio 如, 80% TDI product used for manufacturing soft 泡, 而65%MDI product used for manufacturing hard 泡.

polyether type TPU and polyester type TPU between in 差异

TPU soft can use multiple poly alcohol, large upper can separation is polyether and polyester types.

polyether type (Ether): high strength, hydrolysis resistant and high elastic property, low temperature property can good.

polyester type (Ester): relatively good tensile property can, property can, resistant loss property and resistant solvent agent property can and resistant relatively high temperature degree.

soft 质段 差异, for material property formed effect/influence lower:
resistant strong/high degree       polyester 系     >     polyether 系
撕裂 strong/high degree       polyester 系     >     polyether 系
wear resistant consumption property       polyester 系     >       polyether 系
resistant product property       polyester 系     >     polyether 系
wet gas property     polyester 系     <     polyether 系
low temperature impact property     polyester 系     <     polyether 系
transparent property         polyester 系     >     polyether 系
resistant property         polyester 系     <     polyether 系

七 large difference

production raw materials and formulation 差异

（1） polyether type TPU production raw materials main/primary has 4-4’—二苯基甲烷二异氰 acid ester （MDI）, poly hydrogen 呋喃（PTMEG）, 1, 4— butanediol （BDO）, its in MDI use amount in 40% left right, PTMEG约占40%, BDO约占20%.

（2） polyester type TPU production raw materials main/primary has 4-4’—二苯基甲烷二异氰 acid ester （MDI）, 1, 4— butanediol （BDO）, adipic acid （AA）, its in MDI use amount in 40%, AA约占35%, BDO约占25%.

separation quality distribution and effect/influence

polyether versus for separation quality distribution 遵循Poisson几 rate 方程, versus for separation quality distribution relatively narrow; polyester binary alcohol versus for separation quality distribution from Flory几 rate distribution, versus for separation quality distribution relatively wide.

soft molecular weight for polyurethane ester force property can has effect/influence, generally 说, false polyurethane ester molecular weight same, its soft is polyester, polyurethane ester strong/high degree as polyester alcohol molecular weight increase improve/increase; soft is polyether, polyurethane ester strong/high degree polyether alcohol molecular weight increase decline, elongation upper rise. this is is polyester type soft 段本身极 property relatively strong/high, molecular weight large structure property high, for improvement strong/high degree has 利, polyether soft 段则极 property relatively low, molecular weight increase large, polyurethane ester in hard versus for content decrease small, strong/high degree decline.

force property can comparison

polyether, polyester and other oligomer more alcohol formed soft 段. soft in polyurethane ester in large separation, different oligomer more alcohol and 二异氰 acid ester made polyurethane ester property can same. property strong/high polyester as soft to polyurethane ester elastomer and foam force property can relatively good. is, polyester made formed polyurethane ester property large ester 基, this type of polyurethane ester internal not only hard can formed hydrogen 键, but also soft upper property 基团也 can separation and hard upper property 基团形 formed hydrogen 键, make hard versus can more uniform distribution soft versus in, to elastic property crosslinked function. in room temperature lower certain polyester can formed soft crystallization, effect/influence polyurethane ester property can. polyester type polyurethane ester strong/high degree, oil resistant property, hot oxidation stability property ratio PPG polyether type high, hydrolysis resistant property can ratio polyether type 差.

hydrolysis stability property comparison

polyester type thermoplastic polyurethane (TPU) use carbon 化二亚 amine 进行保护 rear, hydrolysis resistant property has improve/increase. polyether ester type thermoplastic polyurethane (TPU) and polyether type thermoplastic polyurethane (TPU) in high temperature lower hydrolysis resistant property most good.

polyester easy water separation 子 侵袭而发生 fracture, hydrolysis formed acid also can catalytic polyester 进一步 hydrolysis. polyester types type for elastomer physical properties and resistant water property can has effect/influence. polyester alcohol raw materials in 亚甲基数目 increase, made polyester type polyurethane ester elastomer resistant water property improve/increase. ester content relatively small, its resistant water property relatively good. 同样, using/adopting long binary acid combined formed polyester, made polyurethane ester elastomer resistant water property ratio short binary acid polyester type polyurethane ester good.

resistant micro material property comparison

polyester type soft thermoplastic polyurethane (TPU) and wet long time 接触, by micro material 侵蚀, polyether type soft or hard thermoplastic polyurethane (TPU) and polyether type thermoplastic polyurethane (TPU) or hard thermoplastic polyurethane (TPU) usually 不会受 to micro material 侵蚀.

price comparison

polyether type polyurethane ester elastomer ratio polyester type polyurethane ester elastomer in price need high very more, its main/primary causes is:
① polyether type polyurethane ester elastomer tool good hydrolysis resistant property can, low temperature resistance property can, resistant bending property can.
②构 formed TPU soft polyether type more alcohol and polyester type more alcohol versus relatively lower, its production raw materials price relatively high.
③ polyether type more alcohol production process ratio polyester type more alcohol need complex very more.
④ polyether type more alcohol in reaction process in process conditions relatively difficult control.
⑤ in production polyether type more alcohol 时, for production equipment requirements relatively high, meanwhile, production process in also need attention/notes 采取一定 anti measures.

processing process property comparison

1, drying

positive 如我们 知道 that 样, polyurethane ester is property polymer, its in gas in slow slow wet. use wet TPU material melt processing molding, water in processing temperature degree lower gas 化, make products surface light slip, internal generate bubbles, material property reduce, therefore is ensure products property can and anti melt processing water separation gas 化引起 bubbles, in TPU processing front, generally need for material 粒进行 drying 处理.

我们 in front 面TPU ester type and ether type hydrolysis stability property comparison 时候也 already as analysis, due to polyester easy water separation 子 侵袭而发生 fracture, hydrolysis formed acid also can catalytic polyester 进一步 hydrolysis, usually lower, in and other conditions 时, polyester type TPU ratio polyether type TPU water amount need high very more, therefore in drying process in need for polyester type TPU尤 is attention/notes, need attention/notes will its 彻底烘 dry, for dry conditions control.

2, holding pressure stage/phase

polymer melt in injection molding 时, is stage/phase also is injection stage/phase, melt need internal pressure and external pressure combined function. holding pressure stage/phase, polymer melt will to high pressure function, in pressure lower, separation 子链段间 自由体积 need to pressure shrink, due to separation 子链间自由体积 decrease small, large separation 子链段 靠近 make separation function force add strong/high performance viscosity improve/increase, another, due to polyether type TPU its ether inner poly can relatively low, 键 旋转位垒 relatively small, from 而导致 reinforcement separation 子链 紧密链段间 function relatively small, therefore in pressure shrink 时, separation versus for relatively large, is viscosity performance can in relatively large scope/range inner 变化. another, due to polyether type TPU its separation relatively polyester type TPU而言 need many, its property relatively difficult formed, therefore in for polyether type TPU processing process in holding pressure 时, and polyester type TPU versus relatively 而言, polyether type TPU need control relatively long holding pressure time.

3, processing time

due to in generally lower, molecular weight increase make separation 子链段 add long, separation heavy 心移动越 slow, 链段间 versus for 位移抵消 machine more, separation long flexible add large, 缠结点 increase more, understanding and slip difficult, make flow process retardant force increase large, need time and can amount increase, performance viscosity for 剪切 敏感 property. usually lower polyester type TPU照 ratio polyether type TPU separation quality need large, its processing molding time relatively long.

4, processing temperature degree

due to usually lower polyester type TPU照 ratio polyether type TPU separation quality distribution relatively wide, its processing process in temperature degree relatively high. due to polyether type TPU nitrogen oxygen relatively easy fracture, therefore need versus for relatively low temperature degree can achieve for its processing.

5, pressure

due to polyester type TPU its separation inner poly can relatively large, its separation structure in nitrogen oxygen relatively difficult fracture, for its processing bad its separation 子键亦 need relatively high temperature degree and pressure.

6, cooling

due to polyester type TPU inner abrasion scratch relatively large, separation inner poly can relatively large, make its cooling make its positive 常状态 relatively difficult, therefore need relatively long cooling time.

7, flow property

due to polyether type TPU ether inner poly can relatively low, 键 旋转位垒 relatively small, polyether versus for separation quality increase, more 柔顺, its separation tool has high degree property, performance very good flow property, polyester type TPU则稍逊.

（本文转自公众号: polymer/macromolecule, 仅供参考学习）