Bên cạnh PHÂN TÍCH ĐỀ THI THẬT TASK 2 (dạng advantages & disadvantages) Some students work while studying. Discuss the advantages and disadvantages of this trend and give your opinion?NGÀY 04/8/2020 IELTS WRITING GENERAL MÁY TÍNH (kèm bài được sửa hs đi thi), IELTS TUTOR cũng cung cấp luyện đề Nature works Polylactic acid (Đề thi IELTS READING 30/08/2023)
I. Kiến thức liên quan
II. Làm bài online
III. Nature works Polylactic acid (Đề thi IELTS READING 30/08/2023)
Nature works Polylactic acid
A dozen years ago, scientists at Cargill got the idea of converting lactic acid made from corn into plastic while examining possible new uses for materials produced from corn wet milling processes. In the past, several efforts had been made to develop plastics from lactic acid, but with limited success. Achieving this technological breakthrough didn’t come easily, but in time the efforts did succeed. A fermentation and distillation process using com was designed to create a polymer suitable for a broad variety of applications.
B
As an agricultural based firm, Cargill had taken this product as far as it could by 1997.
The company needed a partner with access to plastics markets and polymerization capabilities, and began discussions with The Dow Chemical Company. The next step was the formation of the joint venture that created Cargill Dow LLC. Cargill Dow’s product is the world’s first commercially available plastic made from annually renewable resources such as com:
- Nature Works™ PLA is a family of packaging polymers (carbon-based molecules) made from non-petroleum based resources.
- Ingeo is a family of polymers for fibers made in a similar manner.
C
By applying their unique technology to the processing of natural plant sugars, Cargill Dow has created a more environmentally friendly material that reaches the consumer in clothes, cups, packaging and other products. While Cargill Dow is a stand-alone business, it continues to leverage the agricultural processing, manufacturing and polymer expertise of the two parent companies in order to bring the best possible products to market. >> IELTS TUTOR lưu ý: Phân tích&Bài Sửa HS đạt 7.0"The diagram below shows how to recycle organic waste to produce fertiliser (compost)" IELTS WRITING TASK 1
D
The basic raw materials for PLA are carbon dioxide and water. Growing plants, like com, take these building blocks from the atmosphere and the soil. They are combined in the plant to make carbohydrates (sucrose and starch) through a process driven by photosynthesis. The process for making Nature Works PLA begins when a renewable resource such as corn is milled, separating starch from the raw material. Unrefined dextrose, in turn, is processed from the starch.
E
Cargill Dow turns the unrefined dextrose into lactic acid using a fermentation process similar to that used by beer and wine producers. This is the same lactic acid that is used as a food additive and is found in muscle tissue in the human body. Through a special condensation process, a lactide is formed. This lactide is purified through vacuum distillation and becomes a polymer (the base for Natureworks PLA) that is ready for use through a solvent-free melt process. Development of this new technology allows the company to “harvest” the carbon that living plants remove from the air through photosynthesis. Carbon is stored in plant starches, which can be broken down into natural plant sugars. The carbon and other elements in these natural sugars are then used to make Natureworks PLA. >> IELTS TUTOR lưu ý: PHÂN TÍCH ĐỀ THI 30/5/2020"Some education systems make students focus on certain subjects at the age of 15, while others require students to study a wide range of subjects until they leave school. What are the benefits of each system? Which is better?"IELTS WRITING TASK 2 (kèm bài sửa HS đạt 6.5)
F
Nature Works PLA fits all disposal systems and is fully compostable in commercial composting facilities. With the proper infrastructure, products made from this polymer can be recycled back to a monomer and re-used as a polymer. Thus, at the end of its life cycle, a product made from Nature Works PLA can be broken down into its simplest parts so that no sign of it remains.
G
PLA is now actively competing with traditional materials in packaging and fiber applications throughout the world; based on the technology’s success and promise, Cargill Dow is quickly becoming a premier player in the polymers market. This new polymer now competes head-on with petroleum-based materials like polyester. A wide range of products that vary in molecular weight and crystallinity can be produced, and the blend of physical properties of PLA makes it suited for a broad range of fiber and packaging applications. Fiber and non-woven applications include clothing, fiberfill, blankets and wipes. Packaging applications include packaging films and food and beverage containers.
H
As Nature Works PLA polymers are more oil- and grease-resistant and provide a better flavor and aroma barrier than existing petroleum-based polymers, grocery retailers are increasingly using this packaging for their fresh foods. As companies begin to explore this family of polymers, more potential applications are being identified. For example, PLA possess two properties that are particularly useful for drape fabrics and window furnishings. Their resistance to ultraviolet light is particularly appealing as this reduces the amount of fading in such fabrics, and their refractive index is low, which means fabrics constructed from these polymers can be made with deep colors without requiring large amounts of dye. In addition, sportswear makers have been drawn to the product as it has an inherent ability to take moisture away from the skin and when blended with cotton and wool, the result is garments that are lighter and better at absorbing moisture. >> IELTS TUTOR lưu ý: Phân tích & Sửa đề"Traffic and accommodation problems are increasing and the government should encourage some businesses to move from cities to rural areas. Does the advantages outweigh the disadvantages?" (ngày21/11/2020)
I
PLA combines inexpensive large-scale fermentation with chemical processing to produce a value-added polymer product that improves the environment as well. The source material for PLA is a natural sugar found in plants such as com and using such renewable feedstock presents several environmental benefits. As an alternative to traditional petroleum-based polymers, the production of PLA uses 20%-50% less fossil fuel and releases a lower amount of greenhouse gasses than comparable petroleumbased plastic; carbon dioxide in the atmosphere is removed when the feedstock is grown and is returned to the earth when the polymer is degraded. Because the company is using raw materials that can be regenerated year after year, it is both cost- competitive and environmentally responsible.
Questions 1-4
Write the letters A-F in boxes 1-4 on your answer sheet.
1 scientists manage to
2 Cargill needs to have contacts with
3 Nature work is used for
4 Ingeo is used to
A make things like clothes
B produce plastic from plant
C selling plastic in market
D fermentation process
E drape fabrics
F wrapping products
Write your answers in boxes 31-34 on your answer sheet.
Process: Polylactic acid

Questions 9-10
Choose the correct letter, A, B, c or D.
Write your answers in boxes 9-10 on your answer sheet.
9. Why did choose the PLA as material for food packaging?
A It smells good
B It can save food freshness
C It can be used on other materials
D Some other things need to be revised about it.
10. What is PLA packaging is used for?
A absorbing moisture
B composting facilities
C Packaging fresh food. >> IELTS TUTOR lưu ý: Phân tích +kèm sửa bài"The table below shows the number of visitors in the UK and their average spending from 2003 to 2008" IELTS WRITING TASK 1 (table)
D manufacturing
Questions 11-12
Which two features of PLA are correct?
A It takes in moisture of skin
B It is waterproof
C comfortable sportswear
D It’s fading under the sun
E It is only made in deep color
Questions 13-14
Which two features of PLA are correct?
A It is made of renewable raw materials
B It involves the removal of carbon dioxide
C It is no use of fossil fuel product
D It uses renewable raw resources
E It is sustenance which can absorb the CO2 in the atmosphere
IV. Giải thích từ vựng
A
Lactic acid
- Meaning: Axit lactic (một hợp chất hữu cơ được tìm thấy trong cơ thể và thực phẩm).
- IELTS TUTOR xét ví dụ từ bài đọc: Scientists at Cargill got the idea of converting lactic acid made from corn into plastic while examining possible new uses for materials produced from corn wet milling processes.
- Vietnamese: Các nhà khoa học tại Cargill đã nảy ra ý tưởng chuyển axit lactic từ ngô thành nhựa trong khi xem xét các cách sử dụng mới cho các nguyên liệu từ quá trình xay ngô ướt.
Polymer
- Meaning: Polyme (chất được tạo thành từ các chuỗi phân tử lặp lại).
- IELTS TUTOR xét ví dụ từ bài đọc: A fermentation and distillation process using corn was designed to create a polymer suitable for a broad variety of applications.
- Vietnamese: Một quá trình lên men và chưng cất sử dụng ngô đã được thiết kế để tạo ra một polyme phù hợp cho nhiều ứng dụng khác nhau.
Fermentation
- Meaning: Quá trình lên men.
- IELTS TUTOR xét ví dụ từ bài đọc: A fermentation and distillation process using corn was designed to create a polymer suitable for a broad variety of applications.
- Vietnamese: Một quá trình lên men và chưng cất sử dụng ngô đã được thiết kế để tạo ra một polyme phù hợp cho nhiều ứng dụng khác nhau.
Distillation
- Meaning: Quá trình chưng cất.
- IELTS TUTOR xét ví dụ từ bài đọc: A fermentation and distillation process using corn was designed to create a polymer suitable for a broad variety of applications.
- Vietnamese: Một quá trình lên men và chưng cất sử dụng ngô đã được thiết kế để tạo ra một polyme phù hợp cho nhiều ứng dụng khác nhau.
B
Agricultural-based firm
- Meaning: Công ty dựa trên nông nghiệp.
- IELTS TUTOR xét ví dụ từ bài đọc: As an agricultural-based firm, Cargill had taken this product as far as it could by 1997.
- Vietnamese: Là một công ty dựa trên nông nghiệp, Cargill đã phát triển sản phẩm này hết mức có thể vào năm 1997.
Joint venture
- Meaning: Liên doanh.
- IELTS TUTOR xét ví dụ từ bài đọc: The next step was the formation of the joint venture that created Cargill Dow LLC.
- Vietnamese: Bước tiếp theo là thành lập liên doanh tạo ra Cargill Dow LLC.
C
Environmentally friendly
- Meaning: Thân thiện với môi trường.
- IELTS TUTOR xét ví dụ từ bài đọc: Cargill Dow has created a more environmentally friendly material that reaches the consumer in clothes, cups, packaging and other products.
- Vietnamese: Cargill Dow đã tạo ra một vật liệu thân thiện hơn với môi trường mà người tiêu dùng có thể sử dụng trong quần áo, cốc, bao bì và các sản phẩm khác.
Leverage
- Meaning: Tận dụng (lợi thế hoặc nguồn lực).
- IELTS TUTOR xét ví dụ từ bài đọc: It continues to leverage the agricultural processing, manufacturing, and polymer expertise of the two parent companies.
- Vietnamese: Công ty tiếp tục tận dụng chuyên môn về chế biến nông nghiệp, sản xuất và polyme của hai công ty mẹ.
D
Photosynthesis
- Meaning: Quang hợp.
- IELTS TUTOR xét ví dụ từ bài đọc: They are combined in the plant to make carbohydrates (sucrose and starch) through a process driven by photosynthesis.
- Vietnamese: Chúng được kết hợp trong cây để tạo ra carbohydrate (sucrose và tinh bột) thông qua quá trình quang hợp.
Milled
- Meaning: Xay, nghiền.
- IELTS TUTOR xét ví dụ từ bài đọc: The process for making Nature Works PLA begins when a renewable resource such as corn is milled.
- Vietnamese: Quá trình sản xuất Nature Works PLA bắt đầu khi một nguồn tài nguyên tái tạo như ngô được xay.
E
Fermentation process
- Meaning: Quá trình lên men.
- IELTS TUTOR xét ví dụ từ bài đọc: Cargill Dow turns the unrefined dextrose into lactic acid using a fermentation process similar to that used by beer and wine producers.
- Vietnamese: Cargill Dow biến dextrose chưa tinh chế thành axit lactic bằng cách sử dụng một quy trình lên men tương tự như các nhà sản xuất bia và rượu vang.
Condensation process
- Meaning: Quá trình ngưng tụ.
- IELTS TUTOR xét ví dụ từ bài đọc: Through a special condensation process, a lactide is formed.
- Vietnamese: Thông qua một quá trình ngưng tụ đặc biệt, một lactide được hình thành.
Vacuum distillation
- Meaning: Chưng cất chân không.
- IELTS TUTOR xét ví dụ từ bài đọc: This lactide is purified through vacuum distillation.
- Vietnamese: Lactide này được tinh chế thông qua chưng cất chân không.
F
Compostable
- Meaning: Có thể phân hủy sinh học thành phân bón.
- IELTS TUTOR xét ví dụ từ bài đọc: Nature Works PLA fits all disposal systems and is fully compostable in commercial composting facilities.
- Vietnamese: Nature Works PLA phù hợp với tất cả các hệ thống xử lý rác thải và hoàn toàn có thể phân hủy trong các cơ sở ủ phân thương mại.
Infrastructure
- Meaning: Cơ sở hạ tầng.
- IELTS TUTOR xét ví dụ từ bài đọc: With the proper infrastructure, products made from this polymer can be recycled back to a monomer.
- Vietnamese: Với cơ sở hạ tầng phù hợp, các sản phẩm làm từ polyme này có thể được tái chế thành monomer.
G
Molecular weight
- Meaning: Trọng lượng phân tử.
- IELTS TUTOR xét ví dụ từ bài đọc: A wide range of products that vary in molecular weight and crystallinity can be produced.
- Vietnamese: Một loạt các sản phẩm có trọng lượng phân tử và độ kết tinh khác nhau có thể được sản xuất.
Crystallinity
- Meaning: Độ kết tinh.
- IELTS TUTOR xét ví dụ từ bài đọc: A wide range of products that vary in molecular weight and crystallinity can be produced.
- Vietnamese: Một loạt các sản phẩm có trọng lượng phân tử và độ kết tinh khác nhau có thể được sản xuất.
H
Refractive index
- Meaning: Chỉ số khúc xạ.
- IELTS TUTOR xét ví dụ từ bài đọc: Their refractive index is low, which means fabrics constructed from these polymers can be made with deep colors.
- Vietnamese: Chỉ số khúc xạ của chúng thấp, nghĩa là vải làm từ các polyme này có thể tạo ra màu sắc đậm.
Ultraviolet light
- Meaning: Tia cực tím.
- IELTS TUTOR xét ví dụ từ bài đọc: Their resistance to ultraviolet light is particularly appealing as this reduces the amount of fading in such fabrics.
- Vietnamese: Khả năng chống lại tia cực tím của chúng đặc biệt hấp dẫn vì điều này làm giảm mức độ phai màu của vải.
Absorbing moisture
- Meaning: Hấp thụ độ ẩm.
- IELTS TUTOR xét ví dụ từ bài đọc: The result is garments that are lighter and better at absorbing moisture.
- Vietnamese: Kết quả là quần áo nhẹ hơn và hấp thụ độ ẩm tốt hơn.
V. Đáp án
Đáp án:
1. B | 8. polymer |
2. C | 9. B |
3. F | 10. C |
4. A | 11. A |
5. starch | 12. D |
6. fermentation | 13. A |
7. condensation | 14. C |

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